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 import java.nio.charset.Charset;
28 import java.nio.charset.StandardCharsets;
29
30 import javax.servlet.http.HttpServletRequest;
31
32 import org.apache.turbine.annotation.TurbineService;
33 import org.apache.turbine.pipeline.PipelineData;
34 import org.apache.turbine.services.jsonrpc.JsonRpcService;
35 import org.apache.turbine.util.RunData;
36 import org.jabsorb.JSONRPCBridge;
37
38
39 /**
40 * A Screen class for dealing with JSON-RPC requests. Typically you would
41 * extend this class and override the doOutput() method to use TurbineJsonRpc
42 * to register the POJOs that will provide the functions you are making
43 * available via JSON-RPC. Use JSONSecureScreen if you need the user to be
44 * logged in prior to executing the functions you provide.
45 *
46 * <p>Here is an example from a superclass:
47 * <code>
48 * public void doOutput(PipelineData data) throws Exception
49 * {
50 * User user = data.getUser();
51 *
52 * MyJsonFunctions myFunctions = new MyJsonFunctions(user.getName());
53 *
54 * // Session specific
55 * TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);
56 *
57 * // Global
58 * //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);
59 *
60 * super.doOutput(data);
61 * }
62 * </code>
63 *
64 * <p>The class MyFunctions would be something like:
65 * <code>
66 * public class MyJsonFunctions
67 * {
68 * private String getHello(String clientParameter)
69 * {
70 * return "Hello " + clientParameter;
71 * }
72 * }
73 * </code>
74 *
75 * <p>This code is derived from the com.metaparadigm.jsonrpc.JSONRPCServlet and (after upgrade) checked against
76 * org.jabsorb.JSONRPCServlet.
77 *
78 * @author brad@folkens.com
79 * @author <a href="mailto:seade@backstagetech.com.au">Scott Eade</a>
80 * @version $Id$
81 */
82 public class JSONScreen extends RawScreen
83 {
84 protected static final String JSONRPC_CONTENT_TYPE = "application/json;charset=utf-8";
85
86 protected final static int BUFFER_SIZE = 4096;
87
88 /** Injected service instance */
89 @TurbineService
90 protected JsonRpcService jsonRpcService;
91
92 /**
93 * @see org.apache.turbine.modules.screens.RawScreen#getContentType(org.apache.turbine.pipeline.PipelineData)
94 */
95 @Override
96 protected String getContentType(PipelineData pipelineData)
97 {
98 return JSONRPC_CONTENT_TYPE;
99 }
100
101 /**
102 * Output the dynamic content.
103 *
104 * Encoding is UTF-8. @{@link #JSONRPC_CONTENT_TYPE}: {@value #JSONRPC_CONTENT_TYPE}.
105 *
106 * @param pipelineData The PipelineData object.
107 */
108 @Override
109 protected void doOutput(PipelineData pipelineData) throws Exception
110 {
111 RunData data = pipelineData.getRunData();
112 data.declareDirectResponse();
113 HttpServletRequest request = data.getRequest();
114
115 // we require utf-8, cft
116 Charset charset = StandardCharsets.UTF_8; //request.getCharacterEncoding();
117 BufferedReader in = new BufferedReader(new InputStreamReader(request.getInputStream(), charset));
118
119 // Read the request
120 CharArrayWriter cdata = new CharArrayWriter();
121 char buf[] = new char[BUFFER_SIZE];
122 int ret;
123 while ((ret = in.read(buf, 0, BUFFER_SIZE)) != -1)
124 {
125 cdata.write(buf, 0, ret);
126 }
127
128 // Find the JSONRPCBridge for this session or create one
129 // if it doesn't exist
130 JSONRPCBridge json_bridge = jsonRpcService.getBridge(data.getSession());
131
132 // Process the request
133 Object json_res = jsonRpcService.processCall(cdata, json_bridge, request);
134
135 try (PrintWriter out = new PrintWriter(
136 new OutputStreamWriter(
137 data.getResponse().getOutputStream(), charset)))
138 {
139 out.print(json_res.toString());
140 out.flush();
141 }
142 }
143 }