Struts example source code file (PlainTextResult.java)

This example Struts source code file (PlainTextResult.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

actioninvocation, buffer_size, charset, http, httpservletresponse, httpservletresponse, inputstreamreader, io, logger, plaintextresult, plaintextresult, printwriter, request, response, servlet, servletcontext, servletcontext, string, string

The Struts PlainTextResult.java source code

/*
 * $Id: PlainTextResult.java 651946 2008-04-27 13:41:38Z apetrelli $
 *
 * 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.dispatcher;

import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.nio.charset.Charset;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletResponse;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;

/**
 * <!-- START SNIPPET: description -->
 *
 * A result that send the content out as plain text. Usefull typically when needed
 * to display the raw content of a JSP or Html file for example.
 *
 * <!-- END SNIPPET: description -->
 *
 *
 * <!-- START SNIPPET: params -->
 *
 * <ul>
 *  <li>location (default) = location of the file (jsp/html) to be displayed as plain text.
 *  <li>charSet (optional) = character set to be used. This character set will be used to set the
 *  response type (eg. Content-Type=text/plain; charset=UTF-8) and when reading
 *  using a Reader. Some example of charSet would be UTF-8, ISO-8859-1 etc.
 * </ul>
 *
 * <!-- END SNIPPET: params -->
 *
 *
 * <pre>
 * <!-- START SNIPPET: example -->
 *
 * <action name="displayJspRawContent" >
 *   <result type="plaintext">/myJspFile.jsp</result>
 * </action>
 *
 *
 * <action name="displayJspRawContent" >
 *   <result type="plaintext">
 *      <param name="location">/myJspFile.jsp</param>
 *      <param name="charSet">UTF-8</param>
 *   </result>
 * </action>
 *
 * <!-- END SNIPPET: example -->
 * </pre>
 *
 */
public class PlainTextResult extends StrutsResultSupport {

    public static final int BUFFER_SIZE = 1024;

    private static final Logger LOG = LoggerFactory.getLogger(PlainTextResult.class);

    private static final long serialVersionUID = 3633371605905583950L;

    private String charSet;

    public PlainTextResult() {
        super();
    }

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

    /**
     * Set the character set
     *
     * @return The character set
     */
    public String getCharSet() {
        return charSet;
    }

    /**
     * Set the character set
     *
     * @param charSet The character set
     */
    public void setCharSet(String charSet) {
        this.charSet = charSet;
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.StrutsResultSupport#doExecute(java.lang.String, com.opensymphony.xwork2.ActionInvocation)
     */
    protected void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {

        // verify charset
        Charset charset = null;
        if (charSet != null) {
            if (Charset.isSupported(charSet)) {
                charset = Charset.forName(charSet);
            }
            else {
                LOG.warn("charset ["+charSet+"] is not recognized ");
                charset = null;
            }
        }

        HttpServletResponse response = (HttpServletResponse) invocation.getInvocationContext().get(HTTP_RESPONSE);
        ServletContext servletContext = (ServletContext) invocation.getInvocationContext().get(SERVLET_CONTEXT);


        if (charset != null) {
            response.setContentType("text/plain; charset="+charSet);
        }
        else {
            response.setContentType("text/plain");
        }
        response.setHeader("Content-Disposition", "inline");


        PrintWriter writer = response.getWriter();
        InputStreamReader reader = null;
        try {
            if (charset != null) {
                reader = new InputStreamReader(servletContext.getResourceAsStream(finalLocation), charset);
            }
            else {
                reader = new InputStreamReader(servletContext.getResourceAsStream(finalLocation));
            }
            if (reader == null) {
                LOG.warn("resource at location ["+finalLocation+"] cannot be obtained (return null) from ServletContext !!! ");
            }
            else {
                char[] buffer = new char[BUFFER_SIZE];
                int charRead = 0;
                while((charRead = reader.read(buffer)) != -1) {
                    writer.write(buffer, 0, charRead);
                }
            }
        }
        finally {
            if (reader != null)
                reader.close();
            if (writer != null) {
                writer.flush();
                writer.close();
            }
        }
    }
}