org.springframework.web.servlet
Class FlashMap

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<java.lang.String,java.lang.Object>
          org.springframework.web.servlet.FlashMap

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Comparable<FlashMap>, java.util.Map<java.lang.String,java.lang.Object>

public final class FlashMap
extends java.util.HashMap<java.lang.String,java.lang.Object>
implements java.lang.Comparable<FlashMap>

A FlashMap provides a way for one request to store attributes intended for use in another. This is most commonly needed when redirecting from one URL to another -- e.g. the Post/Redirect/Get pattern. A FlashMap is saved before the redirect (typically in the session) and is made available after the redirect and removed immediately.

A FlashMap can be set up with a request path and request parameters to help identify the target request. Without this information, a FlashMap is made available to the next request, which may or may not be the intended recipient. On a redirect, the target URL is known and for example org.springframework.web.servlet.view.RedirectView has the opportunity to automatically update the current FlashMap with target URL information.

Annotated controllers will usually not use this type directly. See org.springframework.web.servlet.mvc.support.RedirectAttributes for an overview of using flash attributes in annotated controllers.

Since:

3.1

Author:

Rossen Stoyanchev

See Also:

FlashMapManager, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry<K,V>, java.util.AbstractMap.SimpleImmutableEntry<K,V>

Field Summary

private int	createdBy
private long	expirationStartTime
private static long	serialVersionUID
private MultiValueMap<java.lang.String,java.lang.String>	targetRequestParams
private java.lang.String	targetRequestPath
private int	timeToLive

Constructor Summary

FlashMap()
Create a new instance.

FlashMap(int createdBy)
Create a new instance with an id uniquely identifying the creator of this FlashMap.

Method Summary

FlashMap	addTargetRequestParam(java.lang.String name, java.lang.String value) Provide a request parameter identifying the request for this FlashMap.
FlashMap	addTargetRequestParams(MultiValueMap<java.lang.String,java.lang.String> params) Provide request parameters identifying the request for this FlashMap.
int	compareTo(FlashMap other) Compare two FlashMaps and prefer the one that specifies a target URL path or has more target URL parameters.
MultiValueMap<java.lang.String,java.lang.String>	getTargetRequestParams() Return the parameters identifying the target request, or an empty map.
java.lang.String	getTargetRequestPath() Return the target URL path or null.
boolean	isCreatedBy(int createdBy) Whether the given id matches the id of the creator of this FlashMap.
boolean	isExpired() Whether this instance has expired depending on the amount of elapsed time since the call to startExpirationPeriod(int).
void	setTargetRequestPath(java.lang.String path) Provide a URL path to help identify the target request for this FlashMap.
void	startExpirationPeriod(int timeToLive) Start the expiration period for this instance.
java.lang.String	toString()

Methods inherited from class java.util.HashMap

clear, clone, containsKey, containsValue, entrySet, get, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

targetRequestPath

private java.lang.String targetRequestPath

targetRequestParams

private final MultiValueMap<java.lang.String,java.lang.String> targetRequestParams

expirationStartTime

private long expirationStartTime

timeToLive

private int timeToLive

createdBy

private final int createdBy

Constructor Detail

FlashMap

public FlashMap(int createdBy)

Create a new instance with an id uniquely identifying the creator of this FlashMap.

FlashMap

public FlashMap()

Create a new instance.

Method Detail

setTargetRequestPath

public void setTargetRequestPath(java.lang.String path)

Provide a URL path to help identify the target request for this FlashMap. The path may be absolute (e.g. /application/resource) or relative to the current request (e.g. ../resource).

Parameters:

path - the URI path

getTargetRequestPath

public java.lang.String getTargetRequestPath()

Return the target URL path or null.

addTargetRequestParams

public FlashMap addTargetRequestParams(MultiValueMap<java.lang.String,java.lang.String> params)

Provide request parameters identifying the request for this FlashMap. Null or empty keys and values are skipped.

Parameters:

params - a Map with the names and values of expected parameters.

addTargetRequestParam

public FlashMap addTargetRequestParam(java.lang.String name,
                                      java.lang.String value)

Provide a request parameter identifying the request for this FlashMap.

Parameters:

name - the expected parameter name, skipped if null

value - the expected parameter value, skipped if null

getTargetRequestParams

public MultiValueMap<java.lang.String,java.lang.String> getTargetRequestParams()

Return the parameters identifying the target request, or an empty map.

startExpirationPeriod

public void startExpirationPeriod(int timeToLive)

Start the expiration period for this instance.

Parameters:

timeToLive - the number of seconds before expiration

isExpired

public boolean isExpired()

Whether this instance has expired depending on the amount of elapsed time since the call to startExpirationPeriod(int).

isCreatedBy

public boolean isCreatedBy(int createdBy)

Whether the given id matches the id of the creator of this FlashMap.

compareTo

public int compareTo(FlashMap other)

Compare two FlashMaps and prefer the one that specifies a target URL path or has more target URL parameters. Before comparing FlashMap instances ensure that they match a given request.

Specified by:

compareTo in interface java.lang.Comparable<FlashMap>

toString

public java.lang.String toString()

Overrides:

toString in class java.util.AbstractMap<java.lang.String,java.lang.Object>