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.annotation.TurbineService;
31 import org.apache.turbine.pipeline.PipelineData;
32 import org.apache.turbine.services.jsonrpc.JsonRpcService;
33 import org.apache.turbine.util.RunData;
34 import org.jabsorb.JSONRPCBridge;
35
36
37 /**
38 * A Screen class for dealing with JSON-RPC requests. Typically you would
39 * extend this class and override the doOutput() method to use TurbineJsonRpc
40 * to register the POJOs that will provide the functions you are making
41 * available via JSON-RPC. Use JSONSecureScreen if you need the user to be
42 * logged in prior to executing the functions you provide.
43 *
44 * <p>Here is an example from a superclass:
45 * <code>
46 * public void doOutput(PipelineData data) throws Exception
47 * {
48 * User user = data.getUser();
49 *
50 * MyJsonFunctions myFunctions = new MyJsonFunctions(user.getName());
51 *
52 * // Session specific
53 * TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);
54 *
55 * // Global
56 * //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);
57 *
58 * super.doOutput(data);
59 * }
60 * </code>
61 *
62 * <p>The class MyFunctions would be something like:
63 * <code>
64 * public class MyJsonFunctions
65 * {
66 * private String getHello(String clientParameter)
67 * {
68 * return "Hello " + clientParameter;
69 * }
70 * }
71 * </code>
72 *
73 * <p>This code is derived from the com.metaparadigm.jsonrpc.JSONRPCServlet and (after upgrade) checked against
74 * org.jabsorb.JSONRPCServlet.
75 *
76 * @author brad@folkens.com
77 * @author <a href="mailto:seade@backstagetech.com.au">Scott Eade</a>
78 * @version $Id: JSONScreen.java 1718292 2015-12-07 10:23:44Z gk $
79 */
80 public class JSONScreen extends RawScreen
81 {
82 protected static final String JSONRPC_CONTENT_TYPE = "application/json;charset=utf-8";
83
84 protected final static int BUFFER_SIZE = 4096;
85
86 /** Injected service instance */
87 @TurbineService
88 private JsonRpcService jsonRpcService;
89
90 /**
91 * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.pipeline.PipelineData)
92 */
93 @Override
94 protected String getContentType(PipelineData pipelineData)
95 {
96 return JSONRPC_CONTENT_TYPE;
97 }
98
99 /**
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 }