Program: 25470
Project: 25470
Buggy source:
public void handlRequest(HttpServletRequest request,HttpServletResponse response){
  printRequest(request);
  String method=request.getParameter(ServiceConstant.METHOD);
  CommonService obj=null;
  try {
    obj=CommonService.createServiceObjectByMethod(method);
  }
 catch (  InstantiationException e1) {
    log.severe("String_Node_Str" + method + "String_Node_Str"+ e1.toString());
    e1.printStackTrace();
  }
catch (  IllegalAccessException e1) {
    log.severe("String_Node_Str" + method + "String_Node_Str"+ e1.toString());
    e1.printStackTrace();
  }
  try {
    if (obj == null) {
      sendResponseByErrorCode(response,ErrorCode.ERROR_PARA_METHOD_NOT_FOUND);
      return;
    }
    obj.setCassandraClient(cassandraClient);
    obj.setRequest(request);
    if (!obj.validateSecurity(request)) {
      sendResponseByErrorCode(response,ErrorCode.ERROR_INVALID_SECURITY);
      return;
    }
    sendResponseByErrorCode(response,obj.resultCode);
    if (!obj.setDataFromRequest(request)) {
      return;
    }
    obj.printData();
    obj.handleData();
  }
 catch (  HectorException e) {
    obj.resultCode=ErrorCode.ERROR_CASSANDRA;
    log.severe("String_Node_Str" + e.toString());
    e.printStackTrace();
  }
catch (  JSONException e) {
    obj.resultCode=ErrorCode.ERROR_JSON;
    log.severe("String_Node_Str" + e.toString());
    e.printStackTrace();
  }
catch (  Exception e) {
    obj.resultCode=ErrorCode.ERROR_SYSTEM;
    log.severe("String_Node_Str" + e.toString());
    e.printStackTrace();
  }
 finally {
  }
  String responseData=obj.getResponseString();
  sendResponse(response,responseData);
}

Fixed version (ground truth):
public void handlRequest(HttpServletRequest request,HttpServletResponse response){
  printRequest(request);
  String method=request.getParameter(ServiceConstant.METHOD);
  CommonService obj=null;
  try {
    obj=CommonService.createServiceObjectByMethod(method);
  }
 catch (  InstantiationException e1) {
    log.severe("String_Node_Str" + method + "String_Node_Str"+ e1.toString());
    e1.printStackTrace();
  }
catch (  IllegalAccessException e1) {
    log.severe("String_Node_Str" + method + "String_Node_Str"+ e1.toString());
    e1.printStackTrace();
  }
  try {
    if (obj == null) {
      sendResponseByErrorCode(response,ErrorCode.ERROR_PARA_METHOD_NOT_FOUND);
      return;
    }
    obj.setCassandraClient(cassandraClient);
    obj.setRequest(request);
    if (!obj.validateSecurity(request)) {
      sendResponseByErrorCode(response,ErrorCode.ERROR_INVALID_SECURITY);
      return;
    }
    if (!obj.setDataFromRequest(request)) {
      sendResponseByErrorCode(response,obj.resultCode);
      return;
    }
    obj.printData();
    obj.handleData();
  }
 catch (  HectorException e) {
    obj.resultCode=ErrorCode.ERROR_CASSANDRA;
    log.severe("String_Node_Str" + e.toString());
    e.printStackTrace();
  }
catch (  JSONException e) {
    obj.resultCode=ErrorCode.ERROR_JSON;
    log.severe("String_Node_Str" + e.toString());
    e.printStackTrace();
  }
catch (  Exception e) {
    obj.resultCode=ErrorCode.ERROR_SYSTEM;
    log.severe("String_Node_Str" + e.toString());
    e.printStackTrace();
  }
 finally {
  }
  String responseData=obj.getResponseString();
  sendResponse(response,responseData);
}