Hbase的Endpoint实现

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protobuf在windows环境下的安装

option java_package = "com.theta.hbase.coprocessor.protos"; 

option java_outer_classname = "CountProtos"; 

option java_generic_services = true; 

option java_generate_equals_and_hash = true; 

option optimize_for = SPEED; 

/*具体的消息

 *每个message域对应一个内部类，该内部类还包含一个Builder内部类

 *域内字段会生成对应的 setter和getter方法

 *使用Builder内部类来对字段赋值

 **/    

message CountRequest {

       required string startKey = 1;

       required string endKey = 2; 

} 

 

message CountResponse { 

       required int64 count = 1 [default = 0]; 

}

 /*提供服务的类

  *该类没有Builder内部类

  */

service CountService { 

       

       rpc count(CountRequest) 

            returns (CountResponse); 

}  

 

HbaseEndpoint的实现

2、client端使用HTable实例的 coprocessorService 方法发送Rpc请求,得到response结果

   例子：

             public long count(HTableInterface ht, String startKey, String endKey)

                      throws Throwable {

 

               final CountProtos.CountRequest request = CountProtos.CountRequest

                            . newBuilder().setStartKey(startKey).setEndKey(endKey).build();

              

              Map< byte[], Long> results = ht.coprocessorService(

                           CountProtos.CountService. class, null , null,

                            new Batch.Call<CountProtos.CountService, Long>() {

                                   public Long call(CountProtos.CountService counter)throws IOException {

                                         ServerRpcController controller = new ServerRpcController();

                                         BlockingRpcCallback<CountProtos.CountResponse> rpcCallback = new

                                                  BlockingRpcCallback<CountProtos.CountResponse>();

                                         counter.count(controller, request, rpcCallback);

                                         CountProtos.CountResponse response = rpcCallback.get();

                                          if (controller.failedOnException()) {

                                                 throw controller.getFailedOn();

                                         }

                                          return (response != null && response.getCount() != 0) ? 

                                                                 response.getCount() : 0;

                                  }

                           });

 

              System. out.println(results.values());

 

               return results.size();

       }

Hbase的Endpoint实现

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原文地址：http://www.cnblogs.com/hankedang/p/5586356.html