    001package org.apache.turbine.modules.screens;
    002
    003/*
    004 * Licensed to the Apache Software Foundation (ASF) under one
    005 * or more contributor license agreements.  See the NOTICE file
    006 * distributed with this work for additional information
    007 * regarding copyright ownership.  The ASF licenses this file
    008 * to you under the Apache License, Version 2.0 (the
    009 * "License"); you may not use this file except in compliance
    010 * with the License.  You may obtain a copy of the License at
    011 *
    012 *   http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing,
    015 * software distributed under the License is distributed on an
    016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    017 * KIND, either express or implied.  See the License for the
    018 * specific language governing permissions and limitations
    019 * under the License.
    020 */
    021
    022import java.io.BufferedReader;
    023import java.io.CharArrayWriter;
    024import java.io.InputStreamReader;
    025import java.io.OutputStreamWriter;
    026import java.io.PrintWriter;
    027
    028import javax.servlet.http.HttpServletRequest;
    029
    030import org.apache.turbine.annotation.TurbineService;
    031import org.apache.turbine.pipeline.PipelineData;
    032import org.apache.turbine.services.jsonrpc.JsonRpcService;
    033import org.apache.turbine.util.RunData;
    034import org.jabsorb.JSONRPCBridge;
    035
    036
    037/**
    038 * A Screen class for dealing with JSON-RPC requests.  Typically you would
    039 * extend this class and override the doOutput() method to use TurbineJsonRpc
    040 * to register the POJOs that will provide the functions you are making
    041 * available via JSON-RPC.  Use JSONSecureScreen if you need the user to be
    042 * logged in prior to executing the functions you provide.
    043 *
    044 * <p>Here is an example from a superclass:
    045 * <code>
    046 * public void doOutput(PipelineData data) throws Exception
    047 * {
    048 *     User user = data.getUser();
    049 *
    050 *     MyJsonFunctions myFunctions = new MyJsonFunctions(user.getName());
    051 *
    052 *     // Session specific
    053 *     TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);
    054 *
    055 *     // Global
    056 *     //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);
    057 *
    058 *     super.doOutput(data);
    059 * }
    060 * </code>
    061 *
    062 * <p>The class MyFunctions would be something like:
    063 * <code>
    064 * public class MyJsonFunctions
    065 * {
    066 *     private String getHello(String clientParameter)
    067 *     {
    068 *         return "Hello " + clientParameter;
    069 *     }
    070 * }
    071 * </code>
    072 *
    073 * <p>This code is derived from the com.metaparadigm.jsonrpc.JSONRPCServlet and (after upgrade) checked against
    074 * org.jabsorb.JSONRPCServlet.
    075 *
    076 * @author brad@folkens.com
    077 * @author <a href="mailto:seade@backstagetech.com.au">Scott Eade</a>
    078 * @version $Id: JSONScreen.java 1718292 2015-12-07 10:23:44Z gk $
    079 */
    080public class JSONScreen extends RawScreen
    081{
    082    protected static final String JSONRPC_CONTENT_TYPE = "application/json;charset=utf-8";
    083
    084    protected final static int BUFFER_SIZE = 4096;
    085
    086    /** Injected service instance */
    087    @TurbineService
    088    private JsonRpcService jsonRpcService;
    089
    090    /**
    091     * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.pipeline.PipelineData)
    092     */
    093    @Override
    094    protected String getContentType(PipelineData pipelineData)
    095    {
    096        return JSONRPC_CONTENT_TYPE;
    097    }
    098
    099    /**
    100     * Output the dynamic content.
    101     *
    102     * Encodign is UTF-8. @{@link #JSONRPC_CONTENT_TYPE}: {@value #JSONRPC_CONTENT_TYPE}.
    103     *
    104     * @param pipelineData The PipelineData object.
    105     */
    106    @Override
    107    protected void doOutput(PipelineData pipelineData) throws Exception
    108    {
    109        RunData data = getRunData(pipelineData);
    110        data.declareDirectResponse();
    111        HttpServletRequest request = data.getRequest();
    112
    113        // we require utf-8, cft
    114        String charset =  "UTF-8"; //request.getCharacterEncoding();
    115        BufferedReader in = new BufferedReader(new InputStreamReader(request.getInputStream(), charset));
    116
    117        // Read the request
    118        CharArrayWriter cdata = new CharArrayWriter();
    119        char buf[] = new char[BUFFER_SIZE];
    120        int ret;
    121        while ((ret = in.read(buf, 0, BUFFER_SIZE)) != -1)
    122        {
    123            cdata.write(buf, 0, ret);
    124        }
    125
    126        // Find the JSONRPCBridge for this session or create one
    127        // if it doesn't exist
    128        JSONRPCBridge json_bridge = jsonRpcService.getBridge(data.getSession());
    129
    130        // Process the request
    131        Object json_res = jsonRpcService.processCall(cdata, json_bridge, request);
    132
    133        PrintWriter out = new PrintWriter(
    134                new OutputStreamWriter(data.getResponse().getOutputStream(),charset));
    135        out.print(json_res.toString());
    136        out.flush();
    137        out.close();
    138    }
    139}