001 package 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
022 import java.io.BufferedReader;
023 import java.io.CharArrayWriter;
024 import java.io.InputStreamReader;
025 import java.io.OutputStreamWriter;
026 import java.io.PrintWriter;
027
028 import javax.servlet.http.HttpServletRequest;
029
030 import org.apache.turbine.pipeline.PipelineData;
031 import org.apache.turbine.services.jsonrpc.TurbineJsonRpc;
032 import org.apache.turbine.util.RunData;
033
034 import com.metaparadigm.jsonrpc.JSONRPCBridge;
035
036 /**
037 * A Screen class for dealing with JSON-RPC requests. Typically you would
038 * extend this class and override the doOutput() method to use TurbineJsonRpc
039 * to register the POJOs that will provide the functions you are making
040 * available via JSON-RPC. Use JSONSecureScreen if you need the user to be
041 * logged in prior to executing the functions you provide.
042 *
043 * <p>Here is an example from a superclass:
044 * <code>
045 * public void doOutput(RunData data) throws Exception
046 * {
047 * User user = data.getUser();
048 *
049 * MyJsonFunctions myFunctions = new MyJsonFunctions(user.getName());
050 *
051 * // Session specific
052 * TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);
053 *
054 * // Global
055 * //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);
056 *
057 * super.doOutput(data);
058 * }
059 * </code>
060 *
061 * <p>The class MyFunctions would be something like:
062 * <code>
063 * public class MyJsonFunctions
064 * {
065 * private String getHello(String clientParameter)
066 * {
067 * return "Hello " + clientParameter;
068 * }
069 * }
070 * </code>
071 *
072 * <p>This code is derived from the com.metaparadigm.jsonrpc.JSONRPCServlet
073 *
074 * @author brad@folkens.com
075 * @author <a href="mailto:seade@backstagetech.com.au">Scott Eade</a>
076 * @version $Id: JSONScreen.java 958672 2010-06-28 18:42:04Z tv $
077 */
078 public class JSONScreen extends RawScreen
079 {
080 protected static final String JSONRPC_CONTENT_TYPE = "text/plain";
081
082 protected final static int BUFFER_SIZE = 4096;
083
084 /**
085 * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.util.RunData)
086 * @deprecated Use PipelineData version instead.
087 */
088 protected String getContentType(RunData data)
089 {
090 return JSONRPC_CONTENT_TYPE;
091 }
092
093 /**
094 * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.pipeline.PipelineData)
095 */
096 protected String getContentType(PipelineData pipelineData)
097 {
098 return JSONRPC_CONTENT_TYPE;
099 }
100
101 /**
102 * @see org.apache.turbine.modules.screens.RawScreen#doOutput(org.apache.turbine.util.RunData)
103 */
104
105 /**
106 * Output the dynamic content.
107 *
108 * @param data The RunData object.
109 * @deprecated Use PipelineData version instead.
110 */
111 protected void doOutput(RunData data) throws Exception
112 {
113 data.declareDirectResponse();
114 HttpServletRequest request = data.getRequest();
115
116 //String charset = request.getCharacterEncoding();
117 //if(charset == null)
118 //{
119 // charset = "UTF-8";
120 //}
121 //BufferedReader in = new BufferedReader(new InputStreamReader(request.getInputStream(), charset));
122 BufferedReader in = new BufferedReader(new InputStreamReader(request.getInputStream()));
123
124 // Read the request
125 CharArrayWriter cdata = new CharArrayWriter();
126 char buf[] = new char[BUFFER_SIZE];
127 int ret;
128 while ((ret = in.read(buf, 0, BUFFER_SIZE)) != -1)
129 {
130 cdata.write(buf, 0, ret);
131 }
132
133 // Find the JSONRPCBridge for this session or create one
134 // if it doesn't exist
135 JSONRPCBridge json_bridge = TurbineJsonRpc.getBridge(data.getSession());
136
137 // Process the request
138 Object json_res = TurbineJsonRpc.processCall(cdata, json_bridge, request);
139
140 PrintWriter out = new PrintWriter(
141 new OutputStreamWriter(data.getResponse().getOutputStream()));
142 out.print(json_res.toString());
143 out.flush();
144 out.close();
145 }
146 }