/*
* $Id: MessageStoreInterceptor.java 471756 2006-11-06 15:01:43Z husted $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.struts2.interceptor;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ValidationAware;
import com.opensymphony.xwork2.interceptor.Interceptor;
/**
* <!-- START SNIPPET: description -->
*
* An interceptor to store {@link ValidationAware} action's messages / errors and field errors into
* Http Session, such that it will be retrieveable at a later stage. This allows the action's message /
* errors and field errors to be available longer that just the particular http request.
*
* <p/>
*
* In the 'STORE' mode, the interceptor will store the {@link ValidationAware} action's message / errors
* and field errors into Http session.
*
* <p/>
*
* In the 'RETRIEVE' mode, the interceptor will retrieve the stored action's message / errors and field
* errors and put them back into the {@link ValidationAware} action.
*
* <p/>
*
* The interceptor does nothing in the 'NONE' mode, which is the default.
*
* <p/>
*
* The operation mode could be switched using :- <p/>
* 1] Setting the iterceptor parameter eg.
* <pre>
* <action name="submitApplication" ...>
* <interceptor-ref name="store">
* <param name="operationMode">l;STORE</param>
* </interceptor-ref>
* <interceptor-ref name="defaultStack" />
* ....
* </action>
* </pre>
*
* 2] Through request parameter (allowRequestParameterSwitch must be 'true' which is the default)
* <pre>
* // the request will have the operation mode in 'STORE'
* http://localhost:8080/context/submitApplication.action?operationMode=STORE
* </pre>
*
* <!-- END SNIPPET: description -->
*
*
* <!-- START SNIPPET: parameters -->
*
* <ul>
* <li>allowRequestParameterSwitch - To enable request parameter that could switch the operation mode
* of this interceptor. </li>
* <li>requestParameterSwitch - The request parameter that will indicate what mode this
* interceptor is in. </li>
* <li>operationMode - The operation mode this interceptor should be in
* (either 'STORE', 'RETRIEVE' or 'NONE'). 'NONE' being the default.</li>
* </ul>
*
* <!-- END SNIPPET: parameters -->
*
* <p/>
*
* <!-- START SNIPPET: extending -->
*
* The following method could be overriden :-
* <ul>
* <li>getRequestOperationMode - get the operation mode of this interceptor based on the request parameters</li>
* <li>mergeCollection - merge two collections</li>
* <li>mergeMap - merge two map</li>
* </ul>
*
* <!-- END SNIPPET: extending -->
*
* <pre>
* <!-- START SNIPPET: example -->
*
* <action name="submitApplication" ....>
* <interceptor-ref name="store">
* <param name="operationMode">STORE</param>
* </interceptor-ref>
* <interceptor-ref name="defaultStack" />
* <result name="input" type="redirect">applicationFailed.action</result>
* <result type="dispatcher">applicationSuccess.jsp</result>
* </action>
*
* <action name="applicationFailed" ....>
* <interceptor-ref name="store">
* <param name="operationMode">RETRIEVE</param>
* </interceptor-ref>
* <result>applicationFailed.jsp</result>
* </action>
*
* <!-- END SNIPPET: example -->
* </pre>
*
* <!-- START SNIPPET: exampleDescription -->
*
* With the example above, 'submitApplication.action' will have the action messages / errors / field errors stored
* in the Http Session. Later when needed, (in this case, when 'applicationFailed.action' is fired, it
* will get the action messages / errors / field errors stored in the Http Session and put them back into
* the action.
*
* <!-- END SNIPPET: exampleDescription -->
*
* @version $Date: 2006-11-06 10:01:43 -0500 (Mon, 06 Nov 2006) $ $Id: MessageStoreInterceptor.java 471756 2006-11-06 15:01:43Z husted $
*/
public class MessageStoreInterceptor implements Interceptor {
private static final long serialVersionUID = 4491997514314242420L;
private static final Log _log = LogFactory.getLog(MessageStoreInterceptor.class);
public static final String STORE_MODE = "STORE";
public static final String RETRIEVE_MODE = "RETRIEVE";
public static final String NONE = "NONE";
private boolean allowRequestParameterSwitch = true;
private String requestParameterSwitch = "operationMode";
private String operationMode = NONE;
public static String fieldErrorsSessionKey = "__MessageStoreInterceptor_FieldErrors_SessionKey";
public static String actionErrorsSessionKey = "__MessageStoreInterceptor_ActionErrors_SessionKey";
public static String actionMessagesSessionKey = "__MessageStoreInterceptor_ActionMessages_SessionKey";
public void setAllowRequestParameterSwitch(boolean allowRequestParameterSwitch) {
this.allowRequestParameterSwitch = allowRequestParameterSwitch;
}
public boolean getAllowRequestParameterSwitch() {
return this.allowRequestParameterSwitch;
}
public void setRequestParameterSwitch(String requestParameterSwitch) {
this.requestParameterSwitch = requestParameterSwitch;
}
public String getRequestParameterSwitch() {
return this.requestParameterSwitch;
}
public void setOperationMode(String operationMode) {
this.operationMode = operationMode;
}
public String getOperationModel() {
return this.operationMode;
}
public void destroy() {
}
public void init() {
}
public String intercept(ActionInvocation invocation) throws Exception {
_log.debug("entering MessageStoreInterceptor ...");
before(invocation);
String result = invocation.invoke();
after(invocation, result);
_log.debug("exit executing MessageStoreInterceptor");
return result;
}
/**
* Handle the retrieving of field errors / action messages / field errors, which is
* done before action invocation, and the <code>operationMode</code> is 'RETRIEVE'.
*
* @param invocation
* @throws Exception
*/
protected void before(ActionInvocation invocation) throws Exception {
String reqOperationMode = getRequestOperationMode(invocation);
if (RETRIEVE_MODE.equalsIgnoreCase(reqOperationMode) ||
RETRIEVE_MODE.equalsIgnoreCase(operationMode)) {
Object action = invocation.getAction();
if (action instanceof ValidationAware) {
// retrieve error / message from session
Map session = (Map) invocation.getInvocationContext().get(ActionContext.SESSION);
ValidationAware validationAwareAction = (ValidationAware) action;
_log.debug("retrieve error / message from session to populate into action ["+action+"]");
Collection actionErrors = (Collection) session.get(actionErrorsSessionKey);
Collection actionMessages = (Collection) session.get(actionMessagesSessionKey);
Map fieldErrors = (Map) session.get(fieldErrorsSessionKey);
if (actionErrors != null && actionErrors.size() > 0) {
Collection mergedActionErrors = mergeCollection(validationAwareAction.getActionErrors(), actionErrors);
validationAwareAction.setActionErrors(mergedActionErrors);
}
if (actionMessages != null && actionMessages.size() > 0) {
Collection mergedActionMessages = mergeCollection(validationAwareAction.getActionMessages(), actionMessages);
validationAwareAction.setActionMessages(mergedActionMessages);
}
if (fieldErrors != null && fieldErrors.size() > 0) {
Map mergedFieldErrors = mergeMap(validationAwareAction.getFieldErrors(), fieldErrors);
validationAwareAction.setFieldErrors(mergedFieldErrors);
}
session.remove(actionErrorsSessionKey);
session.remove(actionMessagesSessionKey);
session.remove(fieldErrorsSessionKey);
}
}
}
/**
* Handle the storing of field errors / action messages / field errors, which is
* done after action invocation, and the <code>operationMode</code> is in 'STORE'.
*
* @param invocation
* @param result
* @throws Exception
*/
protected void after(ActionInvocation invocation, String result) throws Exception {
String reqOperationMode = getRequestOperationMode(invocation);
if (STORE_MODE.equalsIgnoreCase(reqOperationMode) ||
STORE_MODE.equalsIgnoreCase(operationMode)) {
Object action = invocation.getAction();
if (action instanceof ValidationAware) {
// store error / messages into session
Map session = (Map) invocation.getInvocationContext().get(ActionContext.SESSION);
_log.debug("store action ["+action+"] error/messages into session ");
ValidationAware validationAwareAction = (ValidationAware) action;
session.put(actionErrorsSessionKey, validationAwareAction.getActionErrors());
session.put(actionMessagesSessionKey, validationAwareAction.getActionMessages());
session.put(fieldErrorsSessionKey, validationAwareAction.getFieldErrors());
}
else {
_log.debug("Action ["+action+"] is not ValidationAware, no message / error that are storeable");
}
}
}
/**
* Get the operationMode through request paramter, if <code>allowRequestParameterSwitch</code>
* is 'true', else it simply returns 'NONE', meaning its neither in the 'STORE_MODE' nor
* 'RETRIEVE_MODE'.
*
* @return String
*/
protected String getRequestOperationMode(ActionInvocation invocation) {
String reqOperationMode = NONE;
if (allowRequestParameterSwitch) {
Map reqParams = (Map) invocation.getInvocationContext().get(ActionContext.PARAMETERS);
boolean containsParameter = reqParams.containsKey(requestParameterSwitch);
if (containsParameter) {
String[] reqParamsArr = (String[]) reqParams.get(requestParameterSwitch);
if (reqParamsArr != null && reqParamsArr.length > 0) {
reqOperationMode = reqParamsArr[0];
}
}
}
return reqOperationMode;
}
/**
* Merge <code>col1</code> and <code>col2</code> and return the composite
* <code>Collection</code>.
*
* @param col1
* @param col2
* @return Collection
*/
protected Collection mergeCollection(Collection col1, Collection col2) {
Collection _col1 = (col1 == null ? new ArrayList() : col1);
Collection _col2 = (col2 == null ? new ArrayList() : col2);
_col1.addAll(_col2);
return _col1;
}
/**
* Merge <code>map1</code> and <code>map2</code> and return the composite
* <code>Map</code>
*
* @param map1
* @param map2
* @return Map
*/
protected Map mergeMap(Map map1, Map map2) {
Map _map1 = (map1 == null ? new LinkedHashMap() : map1);
Map _map2 = (map2 == null ? new LinkedHashMap() : map2);
_map1.putAll(_map2);
return _map1;
}
}
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