org.docx4j.template.jsp.engine.JspTemplateImpl.java Source code

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Here is the source code for org.docx4j.template.jsp.engine.JspTemplateImpl.java

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/*
 * Copyright (c) 2018, vindell (https://github.com/vindell).
 *
 * 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.docx4j.template.jsp.engine;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.Map;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.apache.commons.io.IOUtils;

/**
 * 
 * TODO
 * @author <a href="https://github.com/vindell">vindell</a>
 */
public class JspTemplateImpl implements JspTemplate {

    protected final JspEngine engine;
    protected final JspConfig config;
    protected final String name;
    protected HttpServletRequest request = null;
    protected HttpServletResponse response = null;

    public JspTemplateImpl(JspEngine engine, HttpServletRequest request, HttpServletResponse response,
            String name) {
        this.engine = engine;
        this.config = engine.getConfig();
        this.name = name;
        this.request = request;
        this.response = response;
    }

    @Override
    public void render(String requestURL, Map<String, Object> variables, Writer out)
            throws IOException, ServletException {
        ByteArrayInputStream input = null;
        ByteArrayOutputStream output = null;
        try {
            output = new ByteArrayOutputStream();
            doInterpret(requestURL, variables, output);
            input = new ByteArrayInputStream(output.toByteArray());
            IOUtils.copy(input, out, config.getInputEncoding());
        } finally {
            IOUtils.closeQuietly(output);
            IOUtils.closeQuietly(input);
        }
    }

    @Override
    public void render(String requestURL, Map<String, Object> variables, OutputStream out)
            throws IOException, ServletException {
        doInterpret(requestURL, variables, out);
    }

    private void doInterpret(String requestURL, Map<String, Object> variables, OutputStream output)
            throws IOException, ServletException {
        /**
          * ServletContext?RequestDispatcher
          */
        ServletContext sc = request.getSession().getServletContext();
        /**
         * ???reqeustDispatcher
         */
        RequestDispatcher rd = sc.getRequestDispatcher(requestURL);
        /**
         * ByteArrayOutputStream?,??
         */
        final ByteArrayOutputStream baos = new ByteArrayOutputStream();

        /**
         * ServletOutputStreamwrite
         */
        final ServletOutputStream outputStream = new ServletOutputStream() {

            public void write(int b) throws IOException {
                /**
                 * ?
                 */
                baos.write(b);
            }

            @SuppressWarnings("unused")
            public boolean isReady() {
                return false;
            }

        };
        /**
         *  OutputStream  PrintWriter
         * OutputStreamWriter ????? charset ????
         */
        final PrintWriter pw = new PrintWriter(new OutputStreamWriter(baos, config.getOutputEncoding()), true);
        /**
         * ?HttpServletResponse??response
         */
        HttpServletResponse resp = new HttpServletResponseWrapper(response) {
            /**
             * getOutputStream(ServletResponse)ServletOutputStream
             * ?response
             * ?byteArrayOutputStream
             */
            public ServletOutputStream getOutputStream() {
                return outputStream;
            }

            /**
             * ?getWriter(ServletResponse)PrintWriter
             * ???
             */
            public PrintWriter getWriter() {
                return pw;
            }
        };
        /**
         * ?jsp RequestDispatcher.include(ServletRequest request,
         * ServletResponse response) RequestDispatcher??response
         */
        rd.include(request, resp);
        pw.flush();
        /**
         * ByteArrayOutputStreamwriteTo?????ByteArray
         */
        baos.writeTo(output);
    }

    @Override
    public String getName() {
        return name;
    }

}