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    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 }