import org.apache.hadoop.hdfs.protocolPB.NamenodeProtocolPB; //导入依赖的package包/类
private static NamenodeProtocol createNNProxyWithNamenodeProtocol(
    InetSocketAddress address, Configuration conf, UserGroupInformation ugi,
    boolean withRetries) throws IOException {
  NamenodeProtocolPB proxy = (NamenodeProtocolPB) createNameNodeProxy(
      address, conf, ugi, NamenodeProtocolPB.class);
  if (withRetries) { // create the proxy with retries
    RetryPolicy timeoutPolicy = RetryPolicies.exponentialBackoffRetry(5, 200,
            TimeUnit.MILLISECONDS);
    Map<String, RetryPolicy> methodNameToPolicyMap
         = new HashMap<String, RetryPolicy>();
    methodNameToPolicyMap.put("getBlocks", timeoutPolicy);
    methodNameToPolicyMap.put("getAccessKeys", timeoutPolicy);
    NamenodeProtocol translatorProxy =
        new NamenodeProtocolTranslatorPB(proxy);
    return (NamenodeProtocol) RetryProxy.create(
        NamenodeProtocol.class, translatorProxy, methodNameToPolicyMap);
  } else {
    return new NamenodeProtocolTranslatorPB(proxy);
  }
}
 

import org.apache.hadoop.hdfs.protocolPB.NamenodeProtocolPB; //导入依赖的package包/类
@Test
public void testNamenodeProtocol() throws IOException {
  NamenodeProtocol np =
      NameNodeProxies.createNonHAProxy(conf,
          nnAddress, NamenodeProtocol.class, UserGroupInformation.getCurrentUser(),
          true).getProxy();

  boolean exists = RpcClientUtil.isMethodSupported(np,
      NamenodeProtocolPB.class, RPC.RpcKind.RPC_PROTOCOL_BUFFER,
      RPC.getProtocolVersion(NamenodeProtocolPB.class), "rollEditLog");

  assertTrue(exists);
  exists = RpcClientUtil.isMethodSupported(np,
      NamenodeProtocolPB.class, RPC.RpcKind.RPC_PROTOCOL_BUFFER,
      RPC.getProtocolVersion(NamenodeProtocolPB.class), "bogusMethod");
  assertFalse(exists);
}
 

import org.apache.hadoop.hdfs.protocolPB.NamenodeProtocolPB; //导入依赖的package包/类
private static NamenodeProtocol createNNProxyWithNamenodeProtocol(
    InetSocketAddress address, Configuration conf, UserGroupInformation ugi,
    boolean withRetries) throws IOException {
  NamenodeProtocolPB proxy = (NamenodeProtocolPB) createNameNodeProxy(
      address, conf, ugi, NamenodeProtocolPB.class, 0);
  if (withRetries) { // create the proxy with retries
    RetryPolicy timeoutPolicy = RetryPolicies.exponentialBackoffRetry(5, 200,
            TimeUnit.MILLISECONDS);
    Map<String, RetryPolicy> methodNameToPolicyMap
         = new HashMap<String, RetryPolicy>();
    methodNameToPolicyMap.put("getBlocks", timeoutPolicy);
    methodNameToPolicyMap.put("getAccessKeys", timeoutPolicy);
    NamenodeProtocol translatorProxy =
        new NamenodeProtocolTranslatorPB(proxy);
    return (NamenodeProtocol) RetryProxy.create(
        NamenodeProtocol.class, translatorProxy, methodNameToPolicyMap);
  } else {
    return new NamenodeProtocolTranslatorPB(proxy);
  }
}
 

import org.apache.hadoop.hdfs.protocolPB.NamenodeProtocolPB; //导入依赖的package包/类
public void start() throws IOException {
    int rpcHandlerCount = conf.getInt(ProxyConfig.PROXY_HANDLER_COUNT, ProxyConfig.PROXY_HANDLER_COUNT_DEFAULT);
    RPC.setProtocolEngine(conf, ClientNamenodeProtocolPB.class,
            ProtobufRpcEngine.class);
    RPC.setProtocolEngine(conf, NamenodeProtocolPB.class,
            ProtobufRpcEngine.class);

    this.protocol = (ClientProtocol) Proxy.newProxyInstance(
            this.getClass().getClassLoader(),
            new Class[]{ClientProtocol.class},
            this.invocationHandler);

    ClientNamenodeProtocolPB proxy = new ClientNamenodeProtocolServerSideTranslatorPB(this.protocol);
    BlockingService clientNNPbService = ClientNamenodeProtocolProtos.ClientNamenodeProtocol.
            newReflectiveBlockingService(proxy);

    int port = conf.getInt(ProxyConfig.RPC_PORT, ProxyConfig.RPC_PORT_DEFAULT);

    this.rpcServer = new RPC.Builder(conf)
            .setProtocol(org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolPB.class)
            .setInstance(clientNNPbService).setBindAddress("0.0.0.0")
            .setPort(port).setNumHandlers(rpcHandlerCount)
            .setVerbose(false).build();
    this.rpcServer.start();

    InetSocketAddress listenAddr = rpcServer.getListenerAddress();
    rpcAddress = new InetSocketAddress("0.0.0.0", listenAddr.getPort());
}