1 package org.apache.turbine.modules.screens;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.io.BufferedReader;
23 import java.io.CharArrayWriter;
24 import java.io.InputStreamReader;
25 import java.io.OutputStreamWriter;
26 import java.io.PrintWriter;
27
28 import javax.servlet.http.HttpServletRequest;
29
30 import org.apache.turbine.pipeline.PipelineData;
31 import org.apache.turbine.services.jsonrpc.TurbineJsonRpc;
32 import org.apache.turbine.util.RunData;
33
34 import com.metaparadigm.jsonrpc.JSONRPCBridge;
35
36 /**
37 * A Screen class for dealing with JSON-RPC requests. Typically you would
38 * extend this class and override the doOutput() method to use TurbineJsonRpc
39 * to register the POJOs that will provide the functions you are making
40 * available via JSON-RPC. Use JSONSecureScreen if you need the user to be
41 * logged in prior to executing the functions you provide.
42 *
43 * <p>Here is an example from a superclass:
44 * <code>
45 * public void doOutput(RunData data) throws Exception
46 * {
47 * User user = data.getUser();
48 *
49 * MyJsonFunctions myFunctions = new MyJsonFunctions(user.getName());
50 *
51 * // Session specific
52 * TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);
53 *
54 * // Global
55 * //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);
56 *
57 * super.doOutput(data);
58 * }
59 * </code>
60 *
61 * <p>The class MyFunctions would be something like:
62 * <code>
63 * public class MyJsonFunctions
64 * {
65 * private String getHello(String clientParameter)
66 * {
67 * return "Hello " + clientParameter;
68 * }
69 * }
70 * </code>
71 *
72 * <p>This code is derived from the com.metaparadigm.jsonrpc.JSONRPCServlet
73 *
74 * @author brad@folkens.com
75 * @author <a href="mailto:seade@backstagetech.com.au">Scott Eade</a>
76 * @version $Id: JSONScreen.java 958672 2010-06-28 18:42:04Z tv $
77 */
78 public class JSONScreen extends RawScreen
79 {
80 protected static final String JSONRPC_CONTENT_TYPE = "text/plain";
81
82 protected final static int BUFFER_SIZE = 4096;
83
84 /**
85 * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.util.RunData)
86 * @deprecated Use PipelineData version instead.
87 */
88 protected String getContentType(RunData data)
89 {
90 return JSONRPC_CONTENT_TYPE;
91 }
92
93 /**
94 * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.pipeline.PipelineData)
95 */
96 protected String getContentType(PipelineData pipelineData)
97 {
98 return JSONRPC_CONTENT_TYPE;
99 }
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 }