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org.apache.commons.net.nntp
Class NNTPClient

java.lang.Object
  extended by org.apache.commons.net.SocketClient
      extended by org.apache.commons.net.nntp.NNTP
          extended by org.apache.commons.net.nntp.NNTPClient

public class NNTPClient
extends NNTP

NNTPClient encapsulates all the functionality necessary to post and retrieve articles from an NNTP server. As with all classes derived from SocketClient, you must first connect to the server with connect before doing anything, and finally disconnect() after you're completely finished interacting with the server. Remember that the isAllowedToPost() method is defined in NNTP.

You should keep in mind that the NNTP server may choose to prematurely close a connection if the client has been idle for longer than a given time period or if the server is being shutdown by the operator or some other reason. The NNTP class will detect a premature NNTP server connection closing when it receives a NNTPReply.SERVICE_DISCONTINUED response to a command. When that occurs, the NNTP class method encountering that reply will throw an NNTPConnectionClosedException . NNTPConectionClosedException is a subclass of IOException and therefore need not be caught separately, but if you are going to catch it separately, its catch block must appear before the more general IOException catch block. When you encounter an NNTPConnectionClosedException , you must disconnect the connection with disconnect() to properly clean up the system resources used by NNTP. Before disconnecting, you may check the last reply code and text with getReplyCode and getReplyString .

Rather than list it separately for each method, we mention here that every method communicating with the server and throwing an IOException can also throw a MalformedServerReplyException , which is a subclass of IOException. A MalformedServerReplyException will be thrown when the reply received from the server deviates enough from the protocol specification that it cannot be interpreted in a useful manner despite attempts to be as lenient as possible.

Author:
Rory Winston, Ted Wise
See Also:
NNTP, NNTPConnectionClosedException, MalformedServerReplyException

Field Summary
 
Fields inherited from class org.apache.commons.net.nntp.NNTP
_commandSupport_, _reader_, _writer_, DEFAULT_PORT
 
Fields inherited from class org.apache.commons.net.SocketClient
_defaultPort_, _input_, _output_, _serverSocketFactory_, _socket_, _socketFactory_, _timeout_, connectTimeout, NETASCII_EOL
 
Constructor Summary
NNTPClient()
           
 
Method Summary
 boolean authenticate(String username, String password)
          Log into a news server by sending the AUTHINFO USER/AUTHINFO PASS command sequence.
 boolean completePendingCommand()
          There are a few NNTPClient methods that do not complete the entire sequence of NNTP commands to complete a transaction.
 Writer forwardArticle(String articleId)
           
 Iterable<Article> iterateArticleInfo(long lowArticleNumber, long highArticleNumber)
          Return article headers for all articles between lowArticleNumber and highArticleNumber, inclusively, using the XOVER command.
 Iterable<String> iterateNewNews(NewGroupsOrNewsQuery query)
          List all new articles added to the NNTP server since a particular date subject to the conditions of the specified query.
 Iterable<String> iterateNewNewsgroupListing(NewGroupsOrNewsQuery query)
          List all new newsgroups added to the NNTP server since a particular date subject to the conditions of the specified query.
 Iterable<NewsgroupInfo> iterateNewNewsgroups(NewGroupsOrNewsQuery query)
          List all new newsgroups added to the NNTP server since a particular date subject to the conditions of the specified query.
 Iterable<String> iterateNewsgroupListing()
          List all newsgroups served by the NNTP server.
 Iterable<String> iterateNewsgroupListing(String wildmat)
          List the newsgroups that match a given pattern.
 Iterable<NewsgroupInfo> iterateNewsgroups()
          List all newsgroups served by the NNTP server.
 Iterable<NewsgroupInfo> iterateNewsgroups(String wildmat)
          List the newsgroups that match a given pattern.
 String listHelp()
          List the command help from the server.
 String[] listNewNews(NewGroupsOrNewsQuery query)
          List all new articles added to the NNTP server since a particular date subject to the conditions of the specified query.
 NewsgroupInfo[] listNewNewsgroups(NewGroupsOrNewsQuery query)
          List all new newsgroups added to the NNTP server since a particular date subject to the conditions of the specified query.
 NewsgroupInfo[] listNewsgroups()
          List all newsgroups served by the NNTP server.
 NewsgroupInfo[] listNewsgroups(String wildmat)
          List the newsgroups that match a given pattern.
 String[] listOverviewFmt()
          Send a "LIST OVERVIEW.FMT" command to the server.
 boolean logout()
          Logs out of the news server gracefully by sending the QUIT command.
 Writer postArticle()
          Post an article to the NNTP server.
 Reader retrieveArticle()
          Same as retrieveArticle((String) null) Note: the return can be cast to a BufferedReader
 Reader retrieveArticle(int a)
          Deprecated. 3.0 use retrieveArticle(long) instead
 Reader retrieveArticle(int a, ArticlePointer ap)
          Deprecated. 3.0 use retrieveArticle(long, ArticleInfo) instead
 BufferedReader retrieveArticle(long articleNumber)
          Same as retrieveArticle(articleNumber, null)
 BufferedReader retrieveArticle(long articleNumber, ArticleInfo pointer)
          Retrieves an article from the currently selected newsgroup.
 Reader retrieveArticle(String articleId)
          Same as retrieveArticle(articleId, (ArticleInfo) null) Note: the return can be cast to a BufferedReader
 BufferedReader retrieveArticle(String articleId, ArticleInfo pointer)
          Retrieves an article from the NNTP server.
 Reader retrieveArticle(String a, ArticlePointer ap)
          Deprecated. 3.0 use retrieveArticle(String, ArticleInfo) instead
 Reader retrieveArticleBody()
          Same as retrieveArticleBody(null) Note: the return can be cast to a BufferedReader
 Reader retrieveArticleBody(int a)
          Deprecated. 3.0 use retrieveArticleBody(long) instead
 Reader retrieveArticleBody(int a, ArticlePointer ap)
          Deprecated. 3.0 use retrieveArticleBody(long, ArticleInfo) instead
 BufferedReader retrieveArticleBody(long articleNumber)
          Same as retrieveArticleBody(articleNumber, null)
 BufferedReader retrieveArticleBody(long articleNumber, ArticleInfo pointer)
          Retrieves an article body from the currently selected newsgroup.
 Reader retrieveArticleBody(String articleId)
          Same as retrieveArticleBody(articleId, (ArticleInfo) null) Note: the return can be cast to a BufferedReader
 BufferedReader retrieveArticleBody(String articleId, ArticleInfo pointer)
          Retrieves an article body from the NNTP server.
 Reader retrieveArticleBody(String a, ArticlePointer ap)
          Deprecated. 3.0 use retrieveArticleBody(String, ArticleInfo) instead
 Reader retrieveArticleHeader()
          Same as retrieveArticleHeader((String) null) Note: the return can be cast to a BufferedReader
 Reader retrieveArticleHeader(int a)
          Deprecated. 3.0 use retrieveArticleHeader(long) instead
 Reader retrieveArticleHeader(int a, ArticlePointer ap)
          Deprecated. 3.0 use retrieveArticleHeader(long, ArticleInfo) instead
 BufferedReader retrieveArticleHeader(long articleNumber)
          Same as retrieveArticleHeader(articleNumber, null)
 BufferedReader retrieveArticleHeader(long articleNumber, ArticleInfo pointer)
          Retrieves an article header from the currently selected newsgroup.
 Reader retrieveArticleHeader(String articleId)
          Same as retrieveArticleHeader(articleId, (ArticleInfo) null) Note: the return can be cast to a BufferedReader
 BufferedReader retrieveArticleHeader(String articleId, ArticleInfo pointer)
          Retrieves an article header from the NNTP server.
 Reader retrieveArticleHeader(String a, ArticlePointer ap)
          Deprecated. 3.0 use retrieveArticleHeader(String, ArticleInfo) instead
 Reader retrieveArticleInfo(int a)
          Deprecated. 3.0 use retrieveArticleInfo(long) instead
 Reader retrieveArticleInfo(int a, int b)
          Deprecated. 3.0 use retrieveArticleInfo(long, long) instead
 BufferedReader retrieveArticleInfo(long articleNumber)
          Return article headers for a specified post.
 BufferedReader retrieveArticleInfo(long lowArticleNumber, long highArticleNumber)
          Return article headers for all articles between lowArticleNumber and highArticleNumber, inclusively.
 Reader retrieveHeader(String a, int b)
          Deprecated. 3.0 use retrieveHeader(String, long) instead
 Reader retrieveHeader(String s, int l, int h)
          Deprecated. 3.0 use retrieveHeader(String, long, long) instead
 BufferedReader retrieveHeader(String header, long articleNumber)
          Return an article header for a specified post.
 BufferedReader retrieveHeader(String header, long lowArticleNumber, long highArticleNumber)
          Return an article header for all articles between lowArticleNumber and highArticleNumber, inclusively.
 boolean selectArticle(ArticleInfo pointer)
          Same as selectArticle((String) null, articleId) .
 boolean selectArticle(ArticlePointer ap)
          Deprecated. 3.0 use selectArticle(ArticleInfo) instead
 boolean selectArticle(int a)
          Deprecated. 3.0 use selectArticle(long) instead
 boolean selectArticle(int a, ArticlePointer ap)
          Deprecated. 3.0 use selectArticle(long, ArticleInfo) instead
 boolean selectArticle(long articleNumber)
          Same as selectArticle(articleNumber, null)
 boolean selectArticle(long articleNumber, ArticleInfo pointer)
          Select an article in the currently selected newsgroup by its number.
 boolean selectArticle(String articleId)
          Same as selectArticle(articleId, (ArticleInfo) null)
 boolean selectArticle(String articleId, ArticleInfo pointer)
          Select an article by its unique identifier (including enclosing < and >) and return its article number and id through the pointer parameter.
 boolean selectArticle(String a, ArticlePointer ap)
          Deprecated. 3.0 use selectArticle(String, ArticleInfo) instead
 boolean selectNewsgroup(String newsgroup)
          Same as selectNewsgroup(newsgroup, null)
 boolean selectNewsgroup(String newsgroup, NewsgroupInfo info)
          Select the specified newsgroup to be the target of for future article retrieval and posting operations.
 boolean selectNextArticle()
          Same as selectNextArticle((ArticleInfo) null)
 boolean selectNextArticle(ArticleInfo pointer)
          Select the article following the currently selected article in the currently selected newsgroup and return its number and unique id through the pointer parameter.
 boolean selectNextArticle(ArticlePointer ap)
          Deprecated. 3.0 use selectNextArticle(ArticleInfo) instead
 boolean selectPreviousArticle()
          Same as selectPreviousArticle((ArticleInfo) null)
 boolean selectPreviousArticle(ArticleInfo pointer)
          Select the article preceeding the currently selected article in the currently selected newsgroup and return its number and unique id through the pointer parameter.
 boolean selectPreviousArticle(ArticlePointer ap)
          Deprecated. 3.0 use selectPreviousArticle(ArticleInfo) instead
 
Methods inherited from class org.apache.commons.net.nntp.NNTP
_connectAction_, article, article, article, article, authinfoPass, authinfoUser, body, body, body, body, disconnect, getCommandSupport, getReply, getReplyCode, getReplyString, group, head, head, head, head, help, ihave, isAllowedToPost, last, list, listActive, newgroups, newnews, next, post, quit, sendCommand, sendCommand, sendCommand, sendCommand, stat, stat, stat, stat, xhdr, xover
 
Methods inherited from class org.apache.commons.net.SocketClient
addProtocolCommandListener, connect, connect, connect, connect, connect, connect, createCommandSupport, fireCommandSent, fireReplyReceived, getConnectTimeout, getDefaultPort, getDefaultTimeout, getKeepAlive, getLocalAddress, getLocalPort, getProxy, getReceiveBufferSize, getRemoteAddress, getRemotePort, getSendBufferSize, getServerSocketFactory, getSoLinger, getSoTimeout, getTcpNoDelay, isAvailable, isConnected, removeProtocolCommandListener, setConnectTimeout, setDefaultPort, setDefaultTimeout, setKeepAlive, setProxy, setReceiveBufferSize, setSendBufferSize, setServerSocketFactory, setSocketFactory, setSoLinger, setSoTimeout, setTcpNoDelay, verifyRemote
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

NNTPClient

public NNTPClient()
Method Detail

retrieveArticle

public BufferedReader retrieveArticle(String articleId,
                                      ArticleInfo pointer)
                               throws IOException
Retrieves an article from the NNTP server. The article is referenced by its unique article identifier (including the enclosing < and >). The article number and identifier contained in the server reply are returned through an ArticleInfo. The articleId field of the ArticleInfo cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format.

A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.

You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned BufferedReader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned BufferedReader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.

Parameters:
articleId - The unique article identifier of the article to retrieve. If this parameter is null, the currently selected article is retrieved.
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
A DotTerminatedMessageReader instance from which the article be read. null if the article does not exist.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

retrieveArticle

public Reader retrieveArticle(String articleId)
                       throws IOException
Same as retrieveArticle(articleId, (ArticleInfo) null) Note: the return can be cast to a BufferedReader

Throws:
IOException

retrieveArticle

public Reader retrieveArticle()
                       throws IOException
Same as retrieveArticle((String) null) Note: the return can be cast to a BufferedReader

Throws:
IOException

retrieveArticle

public BufferedReader retrieveArticle(long articleNumber,
                                      ArticleInfo pointer)
                               throws IOException
Retrieves an article from the currently selected newsgroup. The article is referenced by its article number. The article number and identifier contained in the server reply are returned through an ArticleInfo. The articleId field of the ArticleInfo cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format.

A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.

You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned BufferedReader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned BufferedReader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.

Parameters:
articleNumber - The number of the the article to retrieve.
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
A DotTerminatedMessageReader instance from which the article be read. null if the article does not exist.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

retrieveArticle

public BufferedReader retrieveArticle(long articleNumber)
                               throws IOException
Same as retrieveArticle(articleNumber, null)

Throws:
IOException

retrieveArticleHeader

public BufferedReader retrieveArticleHeader(String articleId,
                                            ArticleInfo pointer)
                                     throws IOException
Retrieves an article header from the NNTP server. The article is referenced by its unique article identifier (including the enclosing < and >). The article number and identifier contained in the server reply are returned through an ArticleInfo. The articleId field of the ArticleInfo cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format.

A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.

You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned BufferedReader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned BufferedReader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.

Parameters:
articleId - The unique article identifier of the article whose header is being retrieved. If this parameter is null, the header of the currently selected article is retrieved.
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
A DotTerminatedMessageReader instance from which the article header can be read. null if the article does not exist.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

retrieveArticleHeader

public Reader retrieveArticleHeader(String articleId)
                             throws IOException
Same as retrieveArticleHeader(articleId, (ArticleInfo) null) Note: the return can be cast to a BufferedReader

Throws:
IOException

retrieveArticleHeader

public Reader retrieveArticleHeader()
                             throws IOException
Same as retrieveArticleHeader((String) null) Note: the return can be cast to a BufferedReader

Throws:
IOException

retrieveArticleHeader

public BufferedReader retrieveArticleHeader(long articleNumber,
                                            ArticleInfo pointer)
                                     throws IOException
Retrieves an article header from the currently selected newsgroup. The article is referenced by its article number. The article number and identifier contained in the server reply are returned through an ArticleInfo. The articleId field of the ArticleInfo cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format.

A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.

You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned BufferedReader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned BufferedReader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.

Parameters:
articleNumber - The number of the the article whose header is being retrieved.
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
A DotTerminatedMessageReader instance from which the article header can be read. null if the article does not exist.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

retrieveArticleHeader

public BufferedReader retrieveArticleHeader(long articleNumber)
                                     throws IOException
Same as retrieveArticleHeader(articleNumber, null)

Throws:
IOException

retrieveArticleBody

public BufferedReader retrieveArticleBody(String articleId,
                                          ArticleInfo pointer)
                                   throws IOException
Retrieves an article body from the NNTP server. The article is referenced by its unique article identifier (including the enclosing < and >). The article number and identifier contained in the server reply are returned through an ArticleInfo. The articleId field of the ArticleInfo cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format.

A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.

You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned BufferedReader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned BufferedReader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.

Parameters:
articleId - The unique article identifier of the article whose body is being retrieved. If this parameter is null, the body of the currently selected article is retrieved.
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
A DotTerminatedMessageReader instance from which the article body can be read. null if the article does not exist.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

retrieveArticleBody

public Reader retrieveArticleBody(String articleId)
                           throws IOException
Same as retrieveArticleBody(articleId, (ArticleInfo) null) Note: the return can be cast to a BufferedReader

Throws:
IOException

retrieveArticleBody

public Reader retrieveArticleBody()
                           throws IOException
Same as retrieveArticleBody(null) Note: the return can be cast to a BufferedReader

Throws:
IOException

retrieveArticleBody

public BufferedReader retrieveArticleBody(long articleNumber,
                                          ArticleInfo pointer)
                                   throws IOException
Retrieves an article body from the currently selected newsgroup. The article is referenced by its article number. The article number and identifier contained in the server reply are returned through an ArticleInfo. The articleId field of the ArticleInfo cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format.

A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.

You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned BufferedReader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned BufferedReader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.

Parameters:
articleNumber - The number of the the article whose body is being retrieved.
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
A DotTerminatedMessageReader instance from which the article body can be read. null if the article does not exist.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

retrieveArticleBody

public BufferedReader retrieveArticleBody(long articleNumber)
                                   throws IOException
Same as retrieveArticleBody(articleNumber, null)

Throws:
IOException

selectNewsgroup

public boolean selectNewsgroup(String newsgroup,
                               NewsgroupInfo info)
                        throws IOException
Select the specified newsgroup to be the target of for future article retrieval and posting operations. Also return the newsgroup information contained in the server reply through the info parameter.

Parameters:
newsgroup - The newsgroup to select.
info - A parameter through which the newsgroup information of the selected newsgroup contained in the server reply is returned. Set this to null if you do not desire this information.
Returns:
True if the newsgroup exists and was selected, false otherwise.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

selectNewsgroup

public boolean selectNewsgroup(String newsgroup)
                        throws IOException
Same as selectNewsgroup(newsgroup, null)

Throws:
IOException

listHelp

public String listHelp()
                throws IOException
List the command help from the server.

Returns:
The sever help information.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

listOverviewFmt

public String[] listOverviewFmt()
                         throws IOException
Send a "LIST OVERVIEW.FMT" command to the server.

Returns:
the contents of the Overview format, of null if the command failed
Throws:
IOException

selectArticle

public boolean selectArticle(String articleId,
                             ArticleInfo pointer)
                      throws IOException
Select an article by its unique identifier (including enclosing < and >) and return its article number and id through the pointer parameter. This is achieved through the STAT command. According to RFC 977, this will NOT set the current article pointer on the server. To do that, you must reference the article by its number.

Parameters:
articleId - The unique article identifier of the article that is being selectedd. If this parameter is null, the body of the current article is selected
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
True if successful, false if not.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

selectArticle

public boolean selectArticle(String articleId)
                      throws IOException
Same as selectArticle(articleId, (ArticleInfo) null)

Throws:
IOException

selectArticle

public boolean selectArticle(ArticleInfo pointer)
                      throws IOException
Same as selectArticle((String) null, articleId) . Useful for retrieving the current article number.

Throws:
IOException

selectArticle

public boolean selectArticle(long articleNumber,
                             ArticleInfo pointer)
                      throws IOException
Select an article in the currently selected newsgroup by its number. and return its article number and id through the pointer parameter. This is achieved through the STAT command. According to RFC 977, this WILL set the current article pointer on the server. Use this command to select an article before retrieving it, or to obtain an article's unique identifier given its number.

Parameters:
articleNumber - The number of the article to select from the currently selected newsgroup.
pointer - A parameter through which to return the article's number and unique id. Although the articleId field cannot always be trusted because of server deviations from RFC 977 reply formats, we haven't found a server that misformats this information in response to this particular command. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
True if successful, false if not.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

selectArticle

public boolean selectArticle(long articleNumber)
                      throws IOException
Same as selectArticle(articleNumber, null)

Throws:
IOException

selectPreviousArticle

public boolean selectPreviousArticle(ArticleInfo pointer)
                              throws IOException
Select the article preceeding the currently selected article in the currently selected newsgroup and return its number and unique id through the pointer parameter. Because of deviating server implementations, the articleId information cannot be trusted. To obtain the article identifier, issue a selectArticle(pointer.articleNumber, pointer) immediately afterward.

Parameters:
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
True if successful, false if not (e.g., there is no previous article).
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

selectPreviousArticle

public boolean selectPreviousArticle()
                              throws IOException
Same as selectPreviousArticle((ArticleInfo) null)

Throws:
IOException

selectNextArticle

public boolean selectNextArticle(ArticleInfo pointer)
                          throws IOException
Select the article following the currently selected article in the currently selected newsgroup and return its number and unique id through the pointer parameter. Because of deviating server implementations, the articleId information cannot be trusted. To obtain the article identifier, issue a selectArticle(pointer.articleNumber, pointer) immediately afterward.

Parameters:
pointer - A parameter through which to return the article's number and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information.
Returns:
True if successful, false if not (e.g., there is no following article).
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

selectNextArticle

public boolean selectNextArticle()
                          throws IOException
Same as selectNextArticle((ArticleInfo) null)

Throws:
IOException

listNewsgroups

public NewsgroupInfo[] listNewsgroups()
                               throws IOException
List all newsgroups served by the NNTP server. If no newsgroups are served, a zero length array will be returned. If the command fails, null will be returned. The method uses the "LIST" command.

Returns:
An array of NewsgroupInfo instances containing the information for each newsgroup served by the NNTP server. If no newsgroups are served, a zero length array will be returned. If the command fails, null will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
See Also:
iterateNewsgroupListing(), iterateNewsgroups()

iterateNewsgroupListing

public Iterable<String> iterateNewsgroupListing()
                                         throws IOException
List all newsgroups served by the NNTP server. If no newsgroups are served, no entries will be returned. The method uses the "LIST" command.

Returns:
An iterable of NewsgroupInfo instances containing the information for each newsgroup served by the NNTP server. If no newsgroups are served, no entries will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
Since:
3.0

iterateNewsgroups

public Iterable<NewsgroupInfo> iterateNewsgroups()
                                          throws IOException
List all newsgroups served by the NNTP server. If no newsgroups are served, no entries will be returned. The method uses the "LIST" command.

Returns:
An iterable of Strings containing the raw information for each newsgroup served by the NNTP server. If no newsgroups are served, no entries will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
Since:
3.0

listNewsgroups

public NewsgroupInfo[] listNewsgroups(String wildmat)
                               throws IOException
List the newsgroups that match a given pattern. Uses the "LIST ACTIVE" command.

Parameters:
wildmat - a pseudo-regex pattern (cf. RFC 2980)
Returns:
An array of NewsgroupInfo instances containing the information for each newsgroup served by the NNTP server corresponding to the supplied pattern. If no such newsgroups are served, a zero length array will be returned. If the command fails, null will be returned.
Throws:
IOException
See Also:
iterateNewsgroupListing(String), iterateNewsgroups(String)

iterateNewsgroupListing

public Iterable<String> iterateNewsgroupListing(String wildmat)
                                         throws IOException
List the newsgroups that match a given pattern. Uses the "LIST ACTIVE" command.

Parameters:
wildmat - a pseudo-regex pattern (cf. RFC 2980)
Returns:
An iterable of Strings containing the raw information for each newsgroup served by the NNTP server corresponding to the supplied pattern. If no such newsgroups are served, no entries will be returned.
Throws:
IOException
Since:
3.0

iterateNewsgroups

public Iterable<NewsgroupInfo> iterateNewsgroups(String wildmat)
                                          throws IOException
List the newsgroups that match a given pattern. Uses the "LIST ACTIVE" command.

Parameters:
wildmat - a pseudo-regex pattern (cf. RFC 2980)
Returns:
An iterable NewsgroupInfo instances containing the information for each newsgroup served by the NNTP server corresponding to the supplied pattern. If no such newsgroups are served, no entries will be returned.
Throws:
IOException
Since:
3.0

listNewNewsgroups

public NewsgroupInfo[] listNewNewsgroups(NewGroupsOrNewsQuery query)
                                  throws IOException
List all new newsgroups added to the NNTP server since a particular date subject to the conditions of the specified query. If no new newsgroups were added, a zero length array will be returned. If the command fails, null will be returned. This uses the "NEWGROUPS" command.

Parameters:
query - The query restricting how to search for new newsgroups.
Returns:
An array of NewsgroupInfo instances containing the information for each new newsgroup added to the NNTP server. If no newsgroups were added, a zero length array will be returned. If the command fails, null will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
See Also:
iterateNewNewsgroups(NewGroupsOrNewsQuery), iterateNewNewsgroupListing(NewGroupsOrNewsQuery)

iterateNewNewsgroupListing

public Iterable<String> iterateNewNewsgroupListing(NewGroupsOrNewsQuery query)
                                            throws IOException
List all new newsgroups added to the NNTP server since a particular date subject to the conditions of the specified query. If no new newsgroups were added, no entries will be returned. This uses the "NEWGROUPS" command.

Parameters:
query - The query restricting how to search for new newsgroups.
Returns:
An iterable of Strings containing the raw information for each new newsgroup added to the NNTP server. If no newsgroups were added, no entries will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
Since:
3.0

iterateNewNewsgroups

public Iterable<NewsgroupInfo> iterateNewNewsgroups(NewGroupsOrNewsQuery query)
                                             throws IOException
List all new newsgroups added to the NNTP server since a particular date subject to the conditions of the specified query. If no new newsgroups were added, no entries will be returned. This uses the "NEWGROUPS" command.

Parameters:
query - The query restricting how to search for new newsgroups.
Returns:
An iterable of NewsgroupInfo instances containing the information for each new newsgroup added to the NNTP server. If no newsgroups were added, no entries will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
Since:
3.0

listNewNews

public String[] listNewNews(NewGroupsOrNewsQuery query)
                     throws IOException
List all new articles added to the NNTP server since a particular date subject to the conditions of the specified query. If no new new news is found, a zero length array will be returned. If the command fails, null will be returned. You must add at least one newsgroup to the query, else the command will fail. Each String in the returned array is a unique message identifier including the enclosing < and >. This uses the "NEWNEWS" command.

Parameters:
query - The query restricting how to search for new news. You must add at least one newsgroup to the query.
Returns:
An array of String instances containing the unique message identifiers for each new article added to the NNTP server. If no new news is found, a zero length array will be returned. If the command fails, null will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
See Also:
iterateNewNews(NewGroupsOrNewsQuery)

iterateNewNews

public Iterable<String> iterateNewNews(NewGroupsOrNewsQuery query)
                                throws IOException
List all new articles added to the NNTP server since a particular date subject to the conditions of the specified query. If no new new news is found, no entries will be returned. This uses the "NEWNEWS" command. You must add at least one newsgroup to the query, else the command will fail. Each String which is returned is a unique message identifier including the enclosing < and >.

Parameters:
query - The query restricting how to search for new news. You must add at least one newsgroup to the query.
Returns:
An iterator of String instances containing the unique message identifiers for each new article added to the NNTP server. If no new news is found, no strings will be returned.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.
Since:
3.0

completePendingCommand

public boolean completePendingCommand()
                               throws IOException
There are a few NNTPClient methods that do not complete the entire sequence of NNTP commands to complete a transaction. These commands require some action by the programmer after the reception of a positive preliminary command. After the programmer's code completes its actions, it must call this method to receive the completion reply from the server and verify the success of the entire transaction.

For example 

 writer = client.postArticle();
 if(writer == null) // failure
   return false;
 header = new SimpleNNTPHeader("foobar@foo.com", "Just testing");
 header.addNewsgroup("alt.test");
 writer.write(header.toString());
 writer.write("This is just a test");
 writer.close();
 if(!client.completePendingCommand()) // failure
   return false;

Returns:
True if successfully completed, false if not.
Throws:
NNTPConnectionClosedException - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

postArticle

public Writer postArticle()
                   throws IOException
Post an article to the NNTP server. This method returns a DotTerminatedMessageWriter instance to which the article can be written. Null is returned if the posting attempt fails. You should check isAllowedToPost() before trying to post. However, a posting attempt can fail due to malformed headers.

You must not issue any commands to the NNTP server (i.e., call any (other methods) until you finish writing to the returned Writer instance and close it. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned Writer actually writes directly to the NNTP connection. After you close the writer, you can execute new commands. If you do not follow these requirements your program will not work properly.

Different NNTP servers will require different header formats, but you can use the provided SimpleNNTPHeader class to construct the bare minimum acceptable header for most news readers. To construct more complicated headers you should refer to RFC 822. When the Java Mail API is finalized, you will be able to use it to compose fully compliant Internet text messages. The DotTerminatedMessageWriter takes care of doubling line-leading dots and ending the message with a single dot upon closing, so all you have to worry about is writing the header and the message.

Upon closing the returned Writer, you need to call completePendingCommand() to finalize the posting and verify its success or failure from the server reply.

Returns:
A DotTerminatedMessageWriter to which the article (including header) can be written. Returns null if the command fails.
Throws:
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

forwardArticle

public Writer forwardArticle(String articleId)
                      throws IOException
Throws:
IOException

logout

public boolean logout()
               throws IOException
Logs out of the news server gracefully by sending the QUIT command. However, you must still disconnect from the server before you can open a new connection.

Returns:
True if successfully completed, false if not.
Throws:
IOException - If an I/O error occurs while either sending a command to the server or receiving a reply from the server.

authenticate

public boolean authenticate(String username,
                            String password)
                     throws IOException
Log into a news server by sending the AUTHINFO USER/AUTHINFO PASS command sequence. This is usually sent in response to a 480 reply code from the NNTP server.

Parameters:
username - a valid username
password - the corresponding password
Returns:
True for successful login, false for a failure
Throws:
IOException

retrieveArticleInfo

public BufferedReader retrieveArticleInfo(long articleNumber)
                                   throws IOException
Return article headers for a specified post.

Parameters:
articleNumber - the article to retrieve headers for
Returns:
a DotTerminatedReader if successful, null otherwise
Throws:
IOException

retrieveArticleInfo

public BufferedReader retrieveArticleInfo(long lowArticleNumber,
                                          long highArticleNumber)
                                   throws IOException
Return article headers for all articles between lowArticleNumber and highArticleNumber, inclusively. Uses the XOVER command.

Parameters:
lowArticleNumber -
highArticleNumber -
Returns:
a DotTerminatedReader if successful, null otherwise
Throws:
IOException

iterateArticleInfo

public Iterable<Article> iterateArticleInfo(long lowArticleNumber,
                                            long highArticleNumber)
                                     throws IOException
Return article headers for all articles between lowArticleNumber and highArticleNumber, inclusively, using the XOVER command.

Parameters:
lowArticleNumber -
highArticleNumber -
Returns:
an Iterable of Articles
Throws:
IOException - if the command failed
Since:
3.0

retrieveHeader

public BufferedReader retrieveHeader(String header,
                                     long articleNumber)
                              throws IOException
Return an article header for a specified post.

Parameters:
header - the header to retrieve
articleNumber - the article to retrieve the header for
Returns:
a DotTerminatedReader if successful, null otherwise
Throws:
IOException

retrieveHeader

public BufferedReader retrieveHeader(String header,
                                     long lowArticleNumber,
                                     long highArticleNumber)
                              throws IOException
Return an article header for all articles between lowArticleNumber and highArticleNumber, inclusively.

Parameters:
header -
lowArticleNumber -
highArticleNumber -
Returns:
a DotTerminatedReader if successful, null otherwise
Throws:
IOException

retrieveHeader

@Deprecated
public Reader retrieveHeader(String s,
                                        int l,
                                        int h)
                      throws IOException
Deprecated. 3.0 use retrieveHeader(String, long, long) instead

Throws:
IOException

retrieveArticleInfo

@Deprecated
public Reader retrieveArticleInfo(int a,
                                             int b)
                           throws IOException
Deprecated. 3.0 use retrieveArticleInfo(long, long) instead

Throws:
IOException

retrieveHeader

@Deprecated
public Reader retrieveHeader(String a,
                                        int b)
                      throws IOException
Deprecated. 3.0 use retrieveHeader(String, long) instead

Throws:
IOException

selectArticle

@Deprecated
public boolean selectArticle(int a,
                                        ArticlePointer ap)
                      throws IOException
Deprecated. 3.0 use selectArticle(long, ArticleInfo) instead

Throws:
IOException

retrieveArticleInfo

@Deprecated
public Reader retrieveArticleInfo(int a)
                           throws IOException
Deprecated. 3.0 use retrieveArticleInfo(long) instead

Throws:
IOException

selectArticle

@Deprecated
public boolean selectArticle(int a)
                      throws IOException
Deprecated. 3.0 use selectArticle(long) instead

Throws:
IOException

retrieveArticleHeader

@Deprecated
public Reader retrieveArticleHeader(int a)
                             throws IOException
Deprecated. 3.0 use retrieveArticleHeader(long) instead

Throws:
IOException

retrieveArticleHeader

@Deprecated
public Reader retrieveArticleHeader(int a,
                                               ArticlePointer ap)
                             throws IOException
Deprecated. 3.0 use retrieveArticleHeader(long, ArticleInfo) instead

Throws:
IOException

retrieveArticleBody

@Deprecated
public Reader retrieveArticleBody(int a)
                           throws IOException
Deprecated. 3.0 use retrieveArticleBody(long) instead

Throws:
IOException

retrieveArticle

@Deprecated
public Reader retrieveArticle(int a,
                                         ArticlePointer ap)
                       throws IOException
Deprecated. 3.0 use retrieveArticle(long, ArticleInfo) instead

Throws:
IOException

retrieveArticle

@Deprecated
public Reader retrieveArticle(int a)
                       throws IOException
Deprecated. 3.0 use retrieveArticle(long) instead

Throws:
IOException

retrieveArticleBody

@Deprecated
public Reader retrieveArticleBody(int a,
                                             ArticlePointer ap)
                           throws IOException
Deprecated. 3.0 use retrieveArticleBody(long, ArticleInfo) instead

Throws:
IOException

retrieveArticle

@Deprecated
public Reader retrieveArticle(String a,
                                         ArticlePointer ap)
                       throws IOException
Deprecated. 3.0 use retrieveArticle(String, ArticleInfo) instead

Throws:
IOException

retrieveArticleBody

@Deprecated
public Reader retrieveArticleBody(String a,
                                             ArticlePointer ap)
                           throws IOException
Deprecated. 3.0 use retrieveArticleBody(String, ArticleInfo) instead

Throws:
IOException

retrieveArticleHeader

@Deprecated
public Reader retrieveArticleHeader(String a,
                                               ArticlePointer ap)
                             throws IOException
Deprecated. 3.0 use retrieveArticleHeader(String, ArticleInfo) instead

Throws:
IOException

selectArticle

@Deprecated
public boolean selectArticle(String a,
                                        ArticlePointer ap)
                      throws IOException
Deprecated. 3.0 use selectArticle(String, ArticleInfo) instead

Throws:
IOException

selectArticle

@Deprecated
public boolean selectArticle(ArticlePointer ap)
                      throws IOException
Deprecated. 3.0 use selectArticle(ArticleInfo) instead

Throws:
IOException

selectNextArticle

@Deprecated
public boolean selectNextArticle(ArticlePointer ap)
                          throws IOException
Deprecated. 3.0 use selectNextArticle(ArticleInfo) instead

Throws:
IOException

selectPreviousArticle

@Deprecated
public boolean selectPreviousArticle(ArticlePointer ap)
                              throws IOException
Deprecated. 3.0 use selectPreviousArticle(ArticleInfo) instead

Throws:
IOException
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