org.apache.struts.action
Class ActionMessages

java.lang.Object
  org.apache.struts.action.ActionMessages

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

ActionErrors

public class ActionMessages
extends Object
implements Serializable

A class that encapsulates messages. Messages can be either global or they are specific to a particular bean property.

Each individual message is described by an ActionMessage object, which contains a message key (to be looked up in an appropriate message resources database), and up to four placeholder arguments used for parametric substitution in the resulting message.

IMPLEMENTATION NOTE - It is assumed that these objects are created and manipulated only within the context of a single thread. Therefore, no synchronization is required for access to internal collections.

Since:

Struts 1.1

Version:

$Rev: 471754 $ $Date: 2005-08-26 21:58:39 -0400 (Fri, 26 Aug 2005) $

See Also:

Serialized Form

Nested Class Summary

protected class

ActionMessages.ActionMessageItem This class is used to store a set of messages associated with a property/key and the position it was initially added to list.

Field Summary

protected boolean	accessed Have the messages been retrieved from this object?
static String	GLOBAL_MESSAGE The "property name" marker to use for global messages, as opposed to those related to a specific property.
protected int	iCount The current number of the property/key being added.
protected HashMap	messages The accumulated set of ActionMessage objects (represented as an ArrayList) for each property, keyed by property name.

Constructor Summary

ActionMessages()
Create an empty ActionMessages object.

ActionMessages(ActionMessages messages)
Create an ActionMessages object initialized with the given messages.

Method Summary

void	add(ActionMessages actionMessages) Adds the messages from the given ActionMessages object to this set of messages.
void	add(String property, ActionMessage message) Add a message to the set of messages for the specified property.
void	clear() Clear all messages recorded by this object.
Iterator	get() Return the set of all recorded messages, without distinction by which property the messages are associated with.
Iterator	get(String property) Return the set of messages related to a specific property.
boolean	isAccessed() Returns true if the get() or get(String) methods are called.
boolean	isEmpty() Return true if there are no messages recorded in this collection, or false otherwise.
Iterator	properties() Return the set of property names for which at least one message has been recorded.
int	size() Return the number of messages recorded for all properties (including global messages).
int	size(String property) Return the number of messages associated with the specified property.
String	toString() Returns a String representation of this ActionMessages' property name=message list mapping.

Methods inherited from class java.lang.Object

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

Field Detail

GLOBAL_MESSAGE

public static final String GLOBAL_MESSAGE

The "property name" marker to use for global messages, as opposed to those related to a specific property.

See Also:

Constant Field Values

accessed

protected boolean accessed

Have the messages been retrieved from this object?

The controller uses this property to determine if session-scoped messages can be removed.

Since:

Struts 1.2

messages

protected HashMap messages

The accumulated set of ActionMessage objects (represented as an ArrayList) for each property, keyed by property name.

iCount

protected int iCount

The current number of the property/key being added. This is used to maintain the order messages are added.

Constructor Detail

ActionMessages

public ActionMessages()

Create an empty ActionMessages object.

ActionMessages

public ActionMessages(ActionMessages messages)

Create an ActionMessages object initialized with the given messages.

Parameters:

messages - The messages to be initially added to this object. This parameter can be null.

Since:

Struts 1.1

Method Detail

add

public void add(String property,
                ActionMessage message)

Add a message to the set of messages for the specified property. An order of the property/key is maintained based on the initial addition of the property/key.

Parameters:

property - Property name (or ActionMessages.GLOBAL_MESSAGE)

message - The message to be added

add

public void add(ActionMessages actionMessages)

Adds the messages from the given ActionMessages object to this set of messages. The messages are added in the order they are returned from the properties method. If a message's property is already in the current ActionMessages object, it is added to the end of the list for that property. If a message's property is not in the current list it is added to the end of the properties.

Parameters:

actionMessages - The ActionMessages object to be added. This parameter can be null.

Since:

Struts 1.1

clear

public void clear()

Clear all messages recorded by this object.

isEmpty

public boolean isEmpty()

Return true if there are no messages recorded in this collection, or false otherwise.

Returns:

true if there are no messages recorded in this collection; false otherwise.

Since:

Struts 1.1

get

public Iterator get()

Return the set of all recorded messages, without distinction by which property the messages are associated with. If there are no messages recorded, an empty enumeration is returned.

Returns:

An iterator over the messages for all properties.

get

public Iterator get(String property)

Return the set of messages related to a specific property. If there are no such messages, an empty enumeration is returned.

Parameters:

property - Property name (or ActionMessages.GLOBAL_MESSAGE)

Returns:

An iterator over the messages for the specified property.

isAccessed

public boolean isAccessed()

Returns true if the get() or get(String) methods are called.

Returns:

true if the messages have been accessed one or more times.

Since:

Struts 1.2

properties

public Iterator properties()

Return the set of property names for which at least one message has been recorded. If there are no messages, an empty Iterator is returned. If you have recorded global messages, the String value of ActionMessages.GLOBAL_MESSAGE will be one of the returned property names.

Returns:

An iterator over the property names for which messages exist.

size

public int size()

Return the number of messages recorded for all properties (including global messages). NOTE - it is more efficient to call isEmpty if all you care about is whether or not there are any messages at all.

Returns:

The number of messages associated with all properties.

size

public int size(String property)

Return the number of messages associated with the specified property.

Parameters:

property - Property name (or ActionMessages.GLOBAL_MESSAGE)

Returns:

The number of messages associated with the property.

toString

public String toString()

Returns a String representation of this ActionMessages' property name=message list mapping.

Overrides:

toString in class Object

Returns:

String representation of the messages

See Also:

Object.toString()