plugins/velocity/src/main/java/org/apache/struts2/views/velocity/result/VelocityResult.java - struts - Git at Google

 /*
  * 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.views.velocity.result;

 import com.opensymphony.xwork2.ActionContext;
 import com.opensymphony.xwork2.ActionInvocation;
 import com.opensymphony.xwork2.inject.Inject;
 import com.opensymphony.xwork2.util.ValueStack;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.struts2.ServletActionContext;
 import org.apache.struts2.StrutsConstants;
 import org.apache.struts2.result.StrutsResultSupport;
 import org.apache.struts2.views.JspSupportServlet;
 import org.apache.struts2.views.velocity.VelocityManager;
 import org.apache.velocity.Template;
 import org.apache.velocity.app.VelocityEngine;
 import org.apache.velocity.context.Context;

 import javax.servlet.Servlet;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.jsp.JspFactory;
 import javax.servlet.jsp.PageContext;
 import java.io.OutputStreamWriter;
 import java.io.Writer;

 /**
  * <!-- START SNIPPET: description -->
  *
  * Using the Servlet container's {@link JspFactory}, this result mocks a JSP
  * execution environment and then displays a Velocity template that will be
  * streamed directly to the servlet output.
  *
  * <!-- END SNIPPET: description -->
  * <p>
  * <b>This result type takes the following parameters:</b>
  * </p>
  * <!-- START SNIPPET: params -->
  *
  * <ul>
  *
  * <li><b>location (default)</b> - the location of the template to process.</li>
  *
  * <li><b>parse</b> - true by default. If set to false, the location param will
  * not be parsed for Ognl expressions.</li>
  *
  * </ul>
  * <p>
  * This result follows the same rules from {@link StrutsResultSupport}.
  * </p>
  *
  * <!-- END SNIPPET: params -->
  * <p>
  * <b>Example:</b>
  * </p>
  * <pre>
  * <!-- START SNIPPET: example -->
  * &lt;result name="success" type="velocity"&gt;
  *   &lt;param name="location"&gt;foo.vm&lt;/param&gt;
  * &lt;/result&gt;
  * <!-- END SNIPPET: example -->
  * </pre>
  *
  */
 public class VelocityResult extends StrutsResultSupport {

     private static final long serialVersionUID = 7268830767762559424L;

     private static final Logger LOG = LogManager.getLogger(VelocityResult.class);

     private String defaultEncoding;
     private VelocityManager velocityManager;
     private JspFactory jspFactory = JspFactory.getDefaultFactory();

     public VelocityResult() {
         super();
     }

     public VelocityResult(String location) {
         super(location);
     }

     @Inject(StrutsConstants.STRUTS_I18N_ENCODING)
     public void setDefaultEncoding(String val) {
         defaultEncoding = val;
     }

     @Inject
     public void setVelocityManager(VelocityManager mgr) {
         this.velocityManager = mgr;
     }

     /**
      * Creates a Velocity context from the action, loads a Velocity template and executes the
      * template. Output is written to the servlet output stream.
      *
      * @param finalLocation the location of the Velocity template
      * @param invocation    an encapsulation of the action execution state.
      * @throws Exception if an error occurs when creating the Velocity context, loading or executing
      *                   the template or writing output to the servlet response stream.
      */
     public void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {
         ValueStack stack = ActionContext.getContext().getValueStack();

         HttpServletRequest request = ServletActionContext.getRequest();
         HttpServletResponse response = ServletActionContext.getResponse();
         ServletContext servletContext = ServletActionContext.getServletContext();
         Servlet servlet = JspSupportServlet.jspSupportServlet;

         velocityManager.init(servletContext);

         boolean usedJspFactory = false;
         PageContext pageContext = (PageContext) ActionContext.getContext().get(ServletActionContext.PAGE_CONTEXT);

         if (pageContext == null && servlet != null) {
             pageContext = jspFactory.getPageContext(servlet, request, response, null, true, 8192, true);
             ActionContext.getContext().put(ServletActionContext.PAGE_CONTEXT, pageContext);
             usedJspFactory = true;
         }

         try {
             String encoding = getEncoding(finalLocation);
             String contentType = getContentType(finalLocation);

             if (encoding != null) {
                 contentType = contentType + ";charset=" + encoding;
             }

             Template t = getTemplate(stack, velocityManager.getVelocityEngine(), invocation, finalLocation, encoding);

             Context context = createContext(velocityManager, stack, request, response, finalLocation);
             Writer writer = new OutputStreamWriter(response.getOutputStream(), encoding);


             response.setContentType(contentType);

             t.merge(context, writer);

             // always flush the writer (we used to only flush it if this was a jspWriter, but someone asked
             // to do it all the time (WW-829). Since Velocity support is being deprecated, we'll oblige :)
             writer.flush();
         } catch (Exception e) {
             LOG.error("Unable to render velocity template: '{}'", finalLocation, e);
             throw e;
         } finally {
             if (usedJspFactory) {
                 jspFactory.releasePageContext(pageContext);
             }
         }
     }

     /**
      * Retrieve the content type for this template.
      * <p>
      * People can override this method if they want to provide specific content types for specific templates (eg text/xml).
      * </p>
      *
      * @param templateLocation location of template
      * @return The content type associated with this template (default "text/html")
      */
     protected String getContentType(String templateLocation) {
         return "text/html";
     }

     /**
      * Retrieve the encoding for this template.
      * <p>
      * People can override this method if they want to provide specific encodings for specific templates.
      * </p>
      *
      * @param templateLocation location of template
      * @return The encoding associated with this template (defaults to the value of 'struts.i18n.encoding' property)
      */
     protected String getEncoding(String templateLocation) {
         String encoding = defaultEncoding;
         if (encoding == null) {
             encoding = System.getProperty("file.encoding");
         }
         if (encoding == null) {
             encoding = "UTF-8";
         }
         return encoding;
     }

     /**
      * Given a value stack, a Velocity engine, and an action invocation, this method returns the appropriate
      * Velocity template to render.
      *
      * @param stack      the value stack to resolve the location again (when parse equals true)
      * @param velocity   the velocity engine to process the request against
      * @param invocation an encapsulation of the action execution state.
      * @param location   the location of the template
      * @param encoding   the charset encoding of the template
      * @return the template to render
      * @throws Exception when the requested template could not be found
      */
     protected Template getTemplate(ValueStack stack, VelocityEngine velocity, ActionInvocation invocation, String location, String encoding) throws Exception {
         if (!location.startsWith("/")) {
             location = invocation.getProxy().getNamespace() + "/" + location;
         }

         Template template = velocity.getTemplate(location, encoding);

         return template;
     }

     /**
      * Creates the VelocityContext that we'll use to render this page.
      *
      * @param velocityManager a reference to the velocityManager to use
      * @param stack           the value stack to resolve the location against (when parse equals true)
      * @param request         the servlet request
      * @param response        the servlet response
      * @param location        the name of the template that is being used
      * @return the a minted Velocity context.
      */
     protected Context createContext(VelocityManager velocityManager, ValueStack stack, HttpServletRequest request, HttpServletResponse response, String location) {
         return velocityManager.createContext(stack, request, response);
     }
 }
	/*
	* 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.views.velocity.result;

	import com.opensymphony.xwork2.ActionContext;
	import com.opensymphony.xwork2.ActionInvocation;
	import com.opensymphony.xwork2.inject.Inject;
	import com.opensymphony.xwork2.util.ValueStack;
	import org.apache.logging.log4j.LogManager;
	import org.apache.logging.log4j.Logger;
	import org.apache.struts2.ServletActionContext;
	import org.apache.struts2.StrutsConstants;
	import org.apache.struts2.result.StrutsResultSupport;
	import org.apache.struts2.views.JspSupportServlet;
	import org.apache.struts2.views.velocity.VelocityManager;
	import org.apache.velocity.Template;
	import org.apache.velocity.app.VelocityEngine;
	import org.apache.velocity.context.Context;

	import javax.servlet.Servlet;
	import javax.servlet.ServletContext;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;
	import javax.servlet.jsp.JspFactory;
	import javax.servlet.jsp.PageContext;
	import java.io.OutputStreamWriter;
	import java.io.Writer;

	/**
	* <!-- START SNIPPET: description -->
	*
	* Using the Servlet container's {@link JspFactory}, this result mocks a JSP
	* execution environment and then displays a Velocity template that will be
	* streamed directly to the servlet output.
	*
	* <!-- END SNIPPET: description -->
	* <p>
	* <b>This result type takes the following parameters:</b>
	* </p>
	* <!-- START SNIPPET: params -->
	*
	* <ul>
	*
	* <li><b>location (default)</b> - the location of the template to process.</li>
	*
	* <li><b>parse</b> - true by default. If set to false, the location param will
	* not be parsed for Ognl expressions.</li>
	*
	* </ul>
	* <p>
	* This result follows the same rules from {@link StrutsResultSupport}.
	* </p>
	*
	* <!-- END SNIPPET: params -->
	* <p>
	* <b>Example:</b>
	* </p>
	* <pre>
	* <!-- START SNIPPET: example -->
	* <result name="success" type="velocity">
	* <param name="location">foo.vm</param>
	* </result>
	* <!-- END SNIPPET: example -->
	* </pre>
	*
	*/
	public class VelocityResult extends StrutsResultSupport {

	private static final long serialVersionUID = 7268830767762559424L;

	private static final Logger LOG = LogManager.getLogger(VelocityResult.class);

	private String defaultEncoding;
	private VelocityManager velocityManager;
	private JspFactory jspFactory = JspFactory.getDefaultFactory();

	public VelocityResult() {
	super();
	}

	public VelocityResult(String location) {
	super(location);
	}

	@Inject(StrutsConstants.STRUTS_I18N_ENCODING)
	public void setDefaultEncoding(String val) {
	defaultEncoding = val;
	}

	@Inject
	public void setVelocityManager(VelocityManager mgr) {
	this.velocityManager = mgr;
	}

	/**
	* Creates a Velocity context from the action, loads a Velocity template and executes the
	* template. Output is written to the servlet output stream.
	*
	* @param finalLocation the location of the Velocity template
	* @param invocation an encapsulation of the action execution state.
	* @throws Exception if an error occurs when creating the Velocity context, loading or executing
	* the template or writing output to the servlet response stream.
	*/
	public void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {
	ValueStack stack = ActionContext.getContext().getValueStack();

	HttpServletRequest request = ServletActionContext.getRequest();
	HttpServletResponse response = ServletActionContext.getResponse();
	ServletContext servletContext = ServletActionContext.getServletContext();
	Servlet servlet = JspSupportServlet.jspSupportServlet;

	velocityManager.init(servletContext);

	boolean usedJspFactory = false;
	PageContext pageContext = (PageContext) ActionContext.getContext().get(ServletActionContext.PAGE_CONTEXT);

	if (pageContext == null && servlet != null) {
	pageContext = jspFactory.getPageContext(servlet, request, response, null, true, 8192, true);
	ActionContext.getContext().put(ServletActionContext.PAGE_CONTEXT, pageContext);
	usedJspFactory = true;
	}

	try {
	String encoding = getEncoding(finalLocation);
	String contentType = getContentType(finalLocation);

	if (encoding != null) {
	contentType = contentType + ";charset=" + encoding;
	}

	Template t = getTemplate(stack, velocityManager.getVelocityEngine(), invocation, finalLocation, encoding);

	Context context = createContext(velocityManager, stack, request, response, finalLocation);
	Writer writer = new OutputStreamWriter(response.getOutputStream(), encoding);


	response.setContentType(contentType);

	t.merge(context, writer);

	// always flush the writer (we used to only flush it if this was a jspWriter, but someone asked
	// to do it all the time (WW-829). Since Velocity support is being deprecated, we'll oblige :)
	writer.flush();
	} catch (Exception e) {
	LOG.error("Unable to render velocity template: '{}'", finalLocation, e);
	throw e;
	} finally {
	if (usedJspFactory) {
	jspFactory.releasePageContext(pageContext);
	}
	}
	}

	/**
	* Retrieve the content type for this template.
	* <p>
	* People can override this method if they want to provide specific content types for specific templates (eg text/xml).
	* </p>
	*
	* @param templateLocation location of template
	* @return The content type associated with this template (default "text/html")
	*/
	protected String getContentType(String templateLocation) {
	return "text/html";
	}

	/**
	* Retrieve the encoding for this template.
	* <p>
	* People can override this method if they want to provide specific encodings for specific templates.
	* </p>
	*
	* @param templateLocation location of template
	* @return The encoding associated with this template (defaults to the value of 'struts.i18n.encoding' property)
	*/
	protected String getEncoding(String templateLocation) {
	String encoding = defaultEncoding;
	if (encoding == null) {
	encoding = System.getProperty("file.encoding");
	}
	if (encoding == null) {
	encoding = "UTF-8";
	}
	return encoding;
	}

	/**
	* Given a value stack, a Velocity engine, and an action invocation, this method returns the appropriate
	* Velocity template to render.
	*
	* @param stack the value stack to resolve the location again (when parse equals true)
	* @param velocity the velocity engine to process the request against
	* @param invocation an encapsulation of the action execution state.
	* @param location the location of the template
	* @param encoding the charset encoding of the template
	* @return the template to render
	* @throws Exception when the requested template could not be found
	*/
	protected Template getTemplate(ValueStack stack, VelocityEngine velocity, ActionInvocation invocation, String location, String encoding) throws Exception {
	if (!location.startsWith("/")) {
	location = invocation.getProxy().getNamespace() + "/" + location;
	}

	Template template = velocity.getTemplate(location, encoding);

	return template;
	}

	/**
	* Creates the VelocityContext that we'll use to render this page.
	*
	* @param velocityManager a reference to the velocityManager to use
	* @param stack the value stack to resolve the location against (when parse equals true)
	* @param request the servlet request
	* @param response the servlet response
	* @param location the name of the template that is being used
	* @return the a minted Velocity context.
	*/
	protected Context createContext(VelocityManager velocityManager, ValueStack stack, HttpServletRequest request, HttpServletResponse response, String location) {
	return velocityManager.createContext(stack, request, response);
	}
	}