storm 的一个drpc例子

    public static void initConnectDB(){  
            primaryKey = "id";  
            rdbmsUrl = "jdbc:mysql://hadoop/DB" ;  
            rdbmsUserName = "";   
            rdbmsPassword = "";  
              
            connector = new RDBMSConnector();  
            try {  
                con = connector.getConnection(rdbmsUrl, rdbmsUserName, rdbmsPassword);  
                communicator = new RDBMSCommunicator2UFN(con);  
            } catch (Exception e){  
                System.out.println("connect to db exception in initConnectDB()");  
                e.printStackTrace();  
            }  
        }  
          
        public static class GetUserID extends BaseBasicBolt{  
            //private RDBMSCommunicator communicator = null;  
            private ResultSet rs = null;  
              
            @Override  
            public void prepare(Map stormConf, TopologyContext context) {  
                System.out.println("in prepare con : "+con);  
                //this.communicator = new RDBMSCommunicator(con);   
                System.out.println("in pretpare communicator :"+communicator);  
            }  
      
            public void execute(Tuple input, BasicOutputCollector collector) {  
                Object id = input.getValue(0);  
                String userName = input.getString(1);  
                  
                String sql = String.format("select userID from usersinfo where username='%s'", userName);  
                System.out.println("sql in get-user-id: "+sql);  
                rs = communicator.selecteExec(sql);  
                String userID = null;  
                  
                if (rs != null){  
                    try {  
                        rs.next();  
                        userID = rs.getString("userID");  
                    } catch (Exception e){  
                        e.printStackTrace();  
                    }  
                    collector.emit(new Values(id, userID));  
                }  
                  
            }  
      
            public void declareOutputFields(OutputFieldsDeclarer declarer) {  
                declarer.declare(new Fields("id", "userID"));  
            }  
              
        }  
          
        public static class GetUserFunctionsID extends BaseBasicBolt{  
            //private RDBMSCommunicator communicator = null;  
            private ResultSet rs = null;  
              
            @Override  
            public void prepare(Map stormConf, TopologyContext context) {  
                //communicator = new  RDBMSCommunicator(con);   
            }  
      
            public void execute(Tuple input, BasicOutputCollector collector) {  
                Object id = input.getValue(0);  
                String userID = input.getString(1);  
                  
                if (userID == null || userID.trim().length() == 0){  
                    return;  
                }  
                  
                String sql = String.format("select functionID from userfunctions where userID='%s'", userID);  
                System.out.println("sql in get-user-functionid : "+sql);  
                rs = communicator.selecteExec(sql);  
                String functionID = null;  
                  
                if (rs != null){  
                    try {  
                        while(rs.next()){  
                            functionID = rs.getString("functionID");  
                            collector.emit(new Values(id,functionID));  
                        }  
                    } catch(Exception e){  
                        e.printStackTrace();  
                    }  
                }  
            }  
      
            public void declareOutputFields(OutputFieldsDeclarer declarer) {  
                declarer.declare(new Fields("id","functionID"));  
            }  
        }  
          
        public static class GetUserFunctionsName extends BaseBatchBolt{  
            //private RDBMSCommunicator communicator = null;  
            private ResultSet rs = null;  
              
            List<String> functionsName = new ArrayList<String>();  
            BatchOutputCollector _collector;  
            Object _id;  
              
            public void execute(Tuple tuple) {  
                String functionID = tuple.getString(1);  
                  
                if (functionID == null || functionID.trim().length() == 0){  
                    return ;  
                }  
                  
                String sql = String.format("select functionName from functionsinfo where functionID='%s'",functionID);  
                System.out.println("sql in get-user-functionname : "+sql );  
                rs = communicator.selecteExec(sql);  
                String functionName = null;  
                  
                if(rs != null){  
                    try {  
                        rs.next();  
                        functionName = rs.getString("functionName");  
                        functionsName.add(functionName);  
                    } catch (Exception e){  
                        e.printStackTrace();  
                    }  
                }  
            }  
      
            public void finishBatch() {  
                _collector.emit(new Values(_id,functionsName.toString()));  
            }  
      
            public void prepare(Map conf, TopologyContext context,  
                    BatchOutputCollector collector, Object id) {  
                _collector = collector;  
                _id = id;  
            }  
      
            public void declareOutputFields(OutputFieldsDeclarer declarer) {  
                declarer.declare(new Fields("id", "user-funcions-name"));  
            }  
              
        }  
          
        public static LinearDRPCTopologyBuilder construct(){  
             initConnectDB();  
             LinearDRPCTopologyBuilder builder = new LinearDRPCTopologyBuilder("user-functions-name");  
               
             builder.addBolt(new GetUserID(), 2);  
             builder.addBolt(new GetUserFunctionsID(),2).shuffleGrouping();  
             builder.addBolt(new GetUserFunctionsName(),2).fieldsGrouping(new Fields("id","functionID"));  
             return builder;  
              
        }  
        public static void main(String[] args) throws Exception{  
            LinearDRPCTopologyBuilder builder = construct();  
              
              
            Config conf = new Config();  
              
            if(args==null || args.length==0) {  
                conf.setMaxTaskParallelism(3);  
                LocalDRPC drpc = new LocalDRPC();  
                LocalCluster cluster = new LocalCluster();  
                cluster.submitTopology("user-fn-drpc", conf, builder.createLocalTopology(drpc));  
                  
                String[] userNames = new String[] { "qingwu.fu"};  
                for(String un: userNames) {  
                    System.out.println("Functions name of : " + un + ": " + drpc.execute("user-functions-name", un));  
                }  
                cluster.shutdown();  
                drpc.shutdown();  
            } else {  
                conf.setNumWorkers(6);  
                StormSubmitter.submitTopology(args[0], conf, builder.createRemoteTopology());  
            }  
              
        }