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 }