trunk/core/src/main/java/org/apache/struts2/dispatcher/StrutsResultSupport.java - struts - Git at Google

 /*
  * $Id$
  *
  * Copyright 2006 The Apache Software Foundation.
  *
  * Licensed 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.dispatcher;

 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.struts2.StrutsStatics;

 import com.opensymphony.xwork2.ActionInvocation;
 import com.opensymphony.xwork2.Result;
 import com.opensymphony.xwork2.util.TextParseUtil;


 /**
  * <!-- START SNIPPET: javadoc -->
  *
  * A base class for all Struts action execution results.
  * The "location" param is the default parameter, meaning the most common usage of this result would be:
  * <p/>
  * This class provides two common parameters for any subclass:
  * <ul>
  * <li>location - the location to go to after execution (could be a jsp page or another action).
  * It can be parsed as per the rules definied in the
  * {@link TextParseUtil#translateVariables(java.lang.String, com.opensymphony.xwork2.util.OgnlValueStack) translateVariables}
  * method</li>
  * <li>parse - true by default. If set to false, the location param will not be parsed for expressions</li>
  * <li>encode - false by default. If set to false, the location param will not be url encoded. This only have effect when parse is true</li>
  * </ul>
  *
  * <b>NOTE:</b>
  * The encode param will only have effect when parse is true
  *
  * <!-- END SNIPPET: javadoc -->
  *
  * <p/>
  *
  * <!-- START SNIPPET: example -->
  *
  * <p/>
  * In the struts.xml configuration file, these would be included as:
  * <p/>
  * <pre>
  *  &lt;result name="success" type="redirect"&gt;
  *      &lt;param name="<b>location</b>"&gt;foo.jsp&lt;/param&gt;
  *  &lt;/result&gt;</pre>
  * <p/>
  * or
  * <p/>
  * <pre>
  *  &lt;result name="success" type="redirect" &gt;
  *      &lt;param name="<b>location</b>"&gt;foo.jsp?url=${myUrl}&lt;/param&gt;
  *      &lt;param name="<b>parse</b>"&gt;true&lt;/param&gt;
  *      &lt;param name="<b>encode</b>"&gt;true&lt;/param&gt;
  *  &lt;/result&gt;</pre>
  * <p/>
  * In the above case, myUrl will be parsed against Ognl Value Stack and then
  * URL encoded.
  * <p/>
  * or when using the default parameter feature
  * <p/>
  * <pre>
  *  &lt;result name="success" type="redirect"&gt;<b>foo.jsp</b>&lt;/result&gt;</pre>
  * <p/>
  * You should subclass this class if you're interested in adding more parameters or functionality
  * to your Result. If you do subclass this class you will need to
  * override {@link #doExecute(String, ActionInvocation)}.<p>
  * <p/>
  * Any custom result can be defined in struts.xml as:
  * <p/>
  * <pre>
  *  &lt;result-types&gt;
  *      ...
  *      &lt;result-type name="myresult" class="com.foo.MyResult" /&gt;
  *  &lt;/result-types&gt;</pre>
  * <p/>
  * Please see the {@link com.opensymphony.xwork2.Result} class for more info on Results in general.
  *
  * <!-- END SNIPPET: example -->
  *
  * @see com.opensymphony.xwork2.Result
  */
 public abstract class StrutsResultSupport implements Result, StrutsStatics {

 	private static final Log _log = LogFactory.getLog(StrutsResultSupport.class);

     /** The default parameter */
     public static final String DEFAULT_PARAM = "location";

     protected boolean parse = true;
     protected boolean encode = false;
     protected String location;

     /**
      * The location to go to after action execution. This could be a JSP page or another action.
      * The location can contain OGNL expressions which will be evaulated if the <tt>parse</tt>
      * parameter is set to <tt>true</tt>.
      *
      * @param location the location to go to after action execution.
      * @see #setParse(boolean)
      */
     public void setLocation(String location) {
         this.location = location;
     }

     /**
      * Set parse to <tt>true</tt> to indicate that the location should be parsed as an OGNL expression. This
      * is set to <tt>true</tt> by default.
      *
      * @param parse <tt>true</tt> if the location parameter is an OGNL expression, <tt>false</tt> otherwise.
      */
     public void setParse(boolean parse) {
         this.parse = parse;
     }

     /**
      * Set encode to <tt>true</tt> to indicate that the location should be url encoded. This is set to
      * <tt>true</tt> by default
      *
      * @param encode <tt>true</tt> if the location parameter should be url encode, <tt>false</tt> otherwise.
      */
     public void setEncode(boolean encode) {
     	this.encode = encode;
     }

     /**
      * Implementation of the <tt>execute</tt> method from the <tt>Result</tt> interface. This will call
      * the abstract method {@link #doExecute(String, ActionInvocation)} after optionally evaluating the
      * location as an OGNL evaluation.
      *
      * @param invocation the execution state of the action.
      * @throws Exception if an error occurs while executing the result.
      */
     public void execute(ActionInvocation invocation) throws Exception {
         doExecute(conditionalParse(location, invocation), invocation);
     }

     /**
      * Parses the parameter for OGNL expressions against the valuestack
      *
      * @param param The parameter value
      * @param invocation The action invocation instance
      * @return The resulting string
      */
     protected String conditionalParse(String param, ActionInvocation invocation) {
         if (parse && param != null && invocation != null) {
             return TextParseUtil.translateVariables(param, invocation.getStack(),
             		new TextParseUtil.ParsedValueEvaluator() {
 						public Object evaluate(Object parsedValue) {
 							if (encode) {
 								if (parsedValue != null) {
 									try {
 										// use UTF-8 as this is the recommended encoding by W3C to
 										// avoid incompatibilities.
 										return URLEncoder.encode(parsedValue.toString(), "UTF-8");
 									}
 									catch(UnsupportedEncodingException e) {
 										_log.warn("error while trying to encode ["+parsedValue+"]", e);
 									}
 								}
 							}
 							return parsedValue;
 						}
             });
         } else {
         	return param;
         }
     }

     /**
      * 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.
      *
      * @param finalLocation the location (jsp page, action, etc) to go to.
      * @param invocation    the execution state of the action.
      * @throws Exception if an error occurs while executing the result.
      */
     protected abstract void doExecute(String finalLocation, ActionInvocation invocation) throws Exception;
 }
	/*
	* $Id$
	*
	* Copyright 2006 The Apache Software Foundation.
	*
	* Licensed 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.dispatcher;

	import java.io.UnsupportedEncodingException;
	import java.net.URLEncoder;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.struts2.StrutsStatics;

	import com.opensymphony.xwork2.ActionInvocation;
	import com.opensymphony.xwork2.Result;
	import com.opensymphony.xwork2.util.TextParseUtil;


	/**
	* <!-- START SNIPPET: javadoc -->
	*
	* A base class for all Struts action execution results.
	* The "location" param is the default parameter, meaning the most common usage of this result would be:
	* <p/>
	* This class provides two common parameters for any subclass:
	* <ul>
	* <li>location - the location to go to after execution (could be a jsp page or another action).
	* It can be parsed as per the rules definied in the
	* {@link TextParseUtil#translateVariables(java.lang.String, com.opensymphony.xwork2.util.OgnlValueStack) translateVariables}
	* method</li>
	* <li>parse - true by default. If set to false, the location param will not be parsed for expressions</li>
	* <li>encode - false by default. If set to false, the location param will not be url encoded. This only have effect when parse is true</li>
	* </ul>
	*
	* <b>NOTE:</b>
	* The encode param will only have effect when parse is true
	*
	* <!-- END SNIPPET: javadoc -->
	*
	* <p/>
	*
	* <!-- START SNIPPET: example -->
	*
	* <p/>
	* In the struts.xml configuration file, these would be included as:
	* <p/>
	* <pre>
	* <result name="success" type="redirect">
	* <param name="<b>location</b>">foo.jsp</param>
	* </result></pre>
	* <p/>
	* or
	* <p/>
	* <pre>
	* <result name="success" type="redirect" >
	* <param name="<b>location</b>">foo.jsp?url=${myUrl}</param>
	* <param name="<b>parse</b>">true</param>
	* <param name="<b>encode</b>">true</param>
	* </result></pre>
	* <p/>
	* In the above case, myUrl will be parsed against Ognl Value Stack and then
	* URL encoded.
	* <p/>
	* or when using the default parameter feature
	* <p/>
	* <pre>
	* <result name="success" type="redirect"><b>foo.jsp</b></result></pre>
	* <p/>
	* You should subclass this class if you're interested in adding more parameters or functionality
	* to your Result. If you do subclass this class you will need to
	* override {@link #doExecute(String, ActionInvocation)}.<p>
	* <p/>
	* Any custom result can be defined in struts.xml as:
	* <p/>
	* <pre>
	* <result-types>
	* ...
	* <result-type name="myresult" class="com.foo.MyResult" />
	* </result-types></pre>
	* <p/>
	* Please see the {@link com.opensymphony.xwork2.Result} class for more info on Results in general.
	*
	* <!-- END SNIPPET: example -->
	*
	* @see com.opensymphony.xwork2.Result
	*/
	public abstract class StrutsResultSupport implements Result, StrutsStatics {

	private static final Log _log = LogFactory.getLog(StrutsResultSupport.class);

	/** The default parameter */
	public static final String DEFAULT_PARAM = "location";

	protected boolean parse = true;
	protected boolean encode = false;
	protected String location;

	/**
	* The location to go to after action execution. This could be a JSP page or another action.
	* The location can contain OGNL expressions which will be evaulated if the <tt>parse</tt>
	* parameter is set to <tt>true</tt>.
	*
	* @param location the location to go to after action execution.
	* @see #setParse(boolean)
	*/
	public void setLocation(String location) {
	this.location = location;
	}

	/**
	* Set parse to <tt>true</tt> to indicate that the location should be parsed as an OGNL expression. This
	* is set to <tt>true</tt> by default.
	*
	* @param parse <tt>true</tt> if the location parameter is an OGNL expression, <tt>false</tt> otherwise.
	*/
	public void setParse(boolean parse) {
	this.parse = parse;
	}

	/**
	* Set encode to <tt>true</tt> to indicate that the location should be url encoded. This is set to
	* <tt>true</tt> by default
	*
	* @param encode <tt>true</tt> if the location parameter should be url encode, <tt>false</tt> otherwise.
	*/
	public void setEncode(boolean encode) {
	this.encode = encode;
	}

	/**
	* Implementation of the <tt>execute</tt> method from the <tt>Result</tt> interface. This will call
	* the abstract method {@link #doExecute(String, ActionInvocation)} after optionally evaluating the
	* location as an OGNL evaluation.
	*
	* @param invocation the execution state of the action.
	* @throws Exception if an error occurs while executing the result.
	*/
	public void execute(ActionInvocation invocation) throws Exception {
	doExecute(conditionalParse(location, invocation), invocation);
	}

	/**
	* Parses the parameter for OGNL expressions against the valuestack
	*
	* @param param The parameter value
	* @param invocation The action invocation instance
	* @return The resulting string
	*/
	protected String conditionalParse(String param, ActionInvocation invocation) {
	if (parse && param != null && invocation != null) {
	return TextParseUtil.translateVariables(param, invocation.getStack(),
	new TextParseUtil.ParsedValueEvaluator() {
	public Object evaluate(Object parsedValue) {
	if (encode) {
	if (parsedValue != null) {
	try {
	// use UTF-8 as this is the recommended encoding by W3C to
	// avoid incompatibilities.
	return URLEncoder.encode(parsedValue.toString(), "UTF-8");
	}
	catch(UnsupportedEncodingException e) {
	_log.warn("error while trying to encode ["+parsedValue+"]", e);
	}
	}
	}
	return parsedValue;
	}
	});
	} else {
	return param;
	}
	}

	/**
	* 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.
	*
	* @param finalLocation the location (jsp page, action, etc) to go to.
	* @param invocation the execution state of the action.
	* @throws Exception if an error occurs while executing the result.
	*/
	protected abstract void doExecute(String finalLocation, ActionInvocation invocation) throws Exception;
	}