org.apache.struts2.dispatcher
Class StreamResult

java.lang.Object
  org.apache.struts2.dispatcher.StrutsResultSupport
      org.apache.struts2.dispatcher.StreamResult

All Implemented Interfaces:

Result, Serializable, StrutsStatics

public class StreamResult
extends StrutsResultSupport

A custom Result type for sending raw data (via an InputStream) directly to the HttpServletResponse. Very useful for allowing users to download content.

This result type takes the following parameters:

• contentType - the stream mime-type as sent to the web browser (default = text/plain).
• contentLength - the stream length in bytes (the browser displays a progress bar).
• contentDisposition - the content disposition header value for specifing the file name (default = inline, values are typically attachment;filename="document.pdf".
• inputName - the name of the InputStream property from the chained action (default = inputStream).
• bufferSize - the size of the buffer to copy from input to output (default = 1024).
• allowCaching if set to 'false' it will set the headers 'Pragma' and 'Cache-Control' to 'no-cahce', and prevent client from caching the content. (default = true)
• contentCharSet if set to a string, ';charset=value' will be added to the content-type header, where value is the string set. If set to an expression, the result of evaluating the expression will be used. If not set, then no charset will be set on the header

These parameters can also be set by exposing a similarly named getter method on your Action. For example, you can provide getContentType() to override that parameter for the current action.

Example:

 <result name="success" type="stream">
   <param name="contentType">image/jpeg</param>
   <param name="inputName">imageStream</param>
   <param name="contentDisposition">attachment;filename="document.pdf"</param>
   <param name="bufferSize">1024</param>
 </result>
 

See Also:

Serialized Form

Field Summary

protected boolean	allowCaching
protected int	bufferSize
protected String	contentCharSet
protected String	contentDisposition
protected String	contentLength
protected String	contentType
static String	DEFAULT_PARAM
protected String	inputName
protected InputStream	inputStream
protected static Logger	LOG

Fields inherited from interface org.apache.struts2.StrutsStatics

HTTP_REQUEST, HTTP_RESPONSE, PAGE_CONTEXT, SERVLET_CONTEXT, SERVLET_DISPATCHER, STRUTS_ACTION_TAG_INVOCATION, STRUTS_PORTLET_CONTEXT

Constructor Summary

StreamResult()

StreamResult(InputStream in)

Method Summary

protected void	doExecute(String finalLocation, ActionInvocation invocation) Executes the result given a final location (jsp page, action, etc) and the action invocation (the state in which the action was executed).
boolean	getAllowCaching()
int	getBufferSize()
String	getContentCharSet()
String	getContentDisposition()
String	getContentLength()
String	getContentType()
String	getInputName()
protected void	resolveParamsFromStack(ValueStack stack, ActionInvocation invocation) Tries to lookup the parameters on the stack.
void	setAllowCaching(boolean allowCaching) Set allowCaching to false to indicate that the client should be requested not to cache the data stream.
void	setBufferSize(int bufferSize)
void	setContentCharSet(String contentCharSet)
void	setContentDisposition(String contentDisposition)
void	setContentLength(String contentLength)
void	setContentType(String contentType)
void	setInputName(String inputName)

Methods inherited from class org.apache.struts2.dispatcher.StrutsResultSupport

conditionalParse, execute, getLastFinalLocation, getLocation, setEncode, setLocation, setParse

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

protected static final Logger LOG

DEFAULT_PARAM

public static final String DEFAULT_PARAM

See Also:

Constant Field Values

contentType

protected String contentType

contentLength

protected String contentLength

contentDisposition

protected String contentDisposition

contentCharSet

protected String contentCharSet

inputName

protected String inputName

inputStream

protected InputStream inputStream

bufferSize

protected int bufferSize

allowCaching

protected boolean allowCaching

Constructor Detail

StreamResult

public StreamResult()

StreamResult

public StreamResult(InputStream in)

Method Detail

getAllowCaching

public boolean getAllowCaching()

Returns:

Returns the whether or not the client should be requested to allow caching of the data stream.

setAllowCaching

public void setAllowCaching(boolean allowCaching)

Set allowCaching to false to indicate that the client should be requested not to cache the data stream. This is set to false by default

Parameters:

allowCaching - Enable caching.

getBufferSize

public int getBufferSize()

Returns:

Returns the bufferSize.

setBufferSize

public void setBufferSize(int bufferSize)

Parameters:

bufferSize - The bufferSize to set.

getContentType

public String getContentType()

Returns:

Returns the contentType.

setContentType

public void setContentType(String contentType)

Parameters:

contentType - The contentType to set.

getContentLength

public String getContentLength()

Returns:

Returns the contentLength.

setContentLength

public void setContentLength(String contentLength)

Parameters:

contentLength - The contentLength to set.

getContentDisposition

public String getContentDisposition()

Returns:

Returns the Content-disposition header value.

setContentDisposition

public void setContentDisposition(String contentDisposition)

Parameters:

contentDisposition - the Content-disposition header value to use.

getContentCharSet

public String getContentCharSet()

Returns:

Returns the charset specified by the user

setContentCharSet

public void setContentCharSet(String contentCharSet)

Parameters:

contentCharSet - the charset to use on the header when sending the stream

getInputName

public String getInputName()

Returns:

Returns the inputName.

setInputName

public void setInputName(String inputName)

Parameters:

inputName - The inputName to set.

doExecute

protected void doExecute(String finalLocation,
                         ActionInvocation invocation)
                  throws Exception

Description copied from class: StrutsResultSupport

Executes the result given a final location (jsp page, action, etc) and the action invocation (the state in which the action was executed). Subclasses must implement this class to handle custom logic for result handling.

Specified by:

doExecute in class StrutsResultSupport

Parameters:

finalLocation - the location (jsp page, action, etc) to go to.

invocation - the execution state of the action.

Throws:

Exception - if an error occurs while executing the result.

See Also:

StrutsResultSupport.doExecute(java.lang.String, com.opensymphony.xwork2.ActionInvocation)

resolveParamsFromStack

protected void resolveParamsFromStack(ValueStack stack,
                                      ActionInvocation invocation)

Tries to lookup the parameters on the stack. Will override any existing parameters

Parameters:

stack - The current value stack