2.thrift使用

我们使用thrift，写一个helloservice，它有一个方法sayHello，这个方法有一个参数word，它的功能就是在word后面添加一个hello然后返回，这也是服务端要做的事情；客户端拿到返回结果后打印出来。

我们一步一步写一下：

1. 编写idl

   service HelloService{
           string sayHello(1: string word);
   }

2. 我们用thrift编译器编译一下，这里有两种选择，我们可以使用thrift官方提供的编译器：http://thrift.apache.org/docs/install，也可以使用maven的编译插件等

   编译后的代码：

   /**
    * Autogenerated by Thrift Compiler (0.8.0)
    *
    * DO NOT EDIT UNLESS YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING
    *  @generated
    */
   import org.apache.thrift.protocol.TTupleProtocol;
   import org.apache.thrift.scheme.IScheme;
   import org.apache.thrift.scheme.SchemeFactory;
   import org.apache.thrift.scheme.StandardScheme;
   import org.apache.thrift.scheme.TupleScheme;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   import java.util.BitSet;
   import java.util.Collections;
   import java.util.EnumMap;
   import java.util.EnumSet;
   import java.util.HashMap;
   import java.util.Map;
   
   public class HelloService {
   
     public interface Iface {
   
       public String sayHello(String word) throws org.apache.thrift.TException;
   
     }
   
     public interface AsyncIface {
   
       public void sayHello(String word, org.apache.thrift.async.AsyncMethodCallback<AsyncClient.sayHello_call> resultHandler) throws org.apache.thrift.TException;
   
     }
   
     public static class Client extends org.apache.thrift.TServiceClient implements Iface {
       public static class Factory implements org.apache.thrift.TServiceClientFactory<Client> {
         public Factory() {}
         public Client getClient(org.apache.thrift.protocol.TProtocol prot) {
           return new Client(prot);
         }
         public Client getClient(org.apache.thrift.protocol.TProtocol iprot, org.apache.thrift.protocol.TProtocol oprot) {
           return new Client(iprot, oprot);
         }
       }
   
       public Client(org.apache.thrift.protocol.TProtocol prot)
       {
         super(prot, prot);
       }
   
       public Client(org.apache.thrift.protocol.TProtocol iprot, org.apache.thrift.protocol.TProtocol oprot) {
         super(iprot, oprot);
       }
   
       public String sayHello(String word) throws org.apache.thrift.TException
       {
         send_sayHello(word);
         return recv_sayHello();
       }
   
       public void send_sayHello(String word) throws org.apache.thrift.TException
       {
         sayHello_args args = new sayHello_args();
         args.setWord(word);
         sendBase("sayHello", args);
       }
   
       public String recv_sayHello() throws org.apache.thrift.TException
       {
         sayHello_result result = new sayHello_result();
         receiveBase(result, "sayHello");
         if (result.isSetSuccess()) {
           return result.success;
         }
         throw new org.apache.thrift.TApplicationException(org.apache.thrift.TApplicationException.MISSING_RESULT, "sayHello failed: unknown result");
       }
   
     }
     public static class AsyncClient extends org.apache.thrift.async.TAsyncClient implements AsyncIface {
       public static class Factory implements org.apache.thrift.async.TAsyncClientFactory<AsyncClient> {
         private org.apache.thrift.async.TAsyncClientManager clientManager;
         private org.apache.thrift.protocol.TProtocolFactory protocolFactory;
         public Factory(org.apache.thrift.async.TAsyncClientManager clientManager, org.apache.thrift.protocol.TProtocolFactory protocolFactory) {
           this.clientManager = clientManager;
           this.protocolFactory = protocolFactory;
         }
         public AsyncClient getAsyncClient(org.apache.thrift.transport.TNonblockingTransport transport) {
           return new AsyncClient(protocolFactory, clientManager, transport);
         }
       }
   
       public AsyncClient(org.apache.thrift.protocol.TProtocolFactory protocolFactory, org.apache.thrift.async.TAsyncClientManager clientManager, org.apache.thrift.transport.TNonblockingTransport transport) {
         super(protocolFactory, clientManager, transport);
       }
   
       public void sayHello(String word, org.apache.thrift.async.AsyncMethodCallback<sayHello_call> resultHandler) throws org.apache.thrift.TException {
         checkReady();
         sayHello_call method_call = new sayHello_call(word, resultHandler, this, ___protocolFactory, ___transport);
         this.___currentMethod = method_call;
         ___manager.call(method_call);
       }
   
       public static class sayHello_call extends org.apache.thrift.async.TAsyncMethodCall {
         private String word;
         public sayHello_call(String word, org.apache.thrift.async.AsyncMethodCallback<sayHello_call> resultHandler, org.apache.thrift.async.TAsyncClient client, org.apache.thrift.protocol.TProtocolFactory protocolFactory, org.apache.thrift.transport.TNonblockingTransport transport) throws org.apache.thrift.TException {
           super(client, protocolFactory, transport, resultHandler, false);
           this.word = word;
         }
   
         public void write_args(org.apache.thrift.protocol.TProtocol prot) throws org.apache.thrift.TException {
           prot.writeMessageBegin(new org.apache.thrift.protocol.TMessage("sayHello", org.apache.thrift.protocol.TMessageType.CALL, 0));
           sayHello_args args = new sayHello_args();
           args.setWord(word);
           args.write(prot);
           prot.writeMessageEnd();
         }
   
         public String getResult() throws org.apache.thrift.TException {
           if (getState() != org.apache.thrift.async.TAsyncMethodCall.State.RESPONSE_READ) {
             throw new IllegalStateException("Method call not finished!");
           }
           org.apache.thrift.transport.TMemoryInputTransport memoryTransport = new org.apache.thrift.transport.TMemoryInputTransport(getFrameBuffer().array());
           org.apache.thrift.protocol.TProtocol prot = client.getProtocolFactory().getProtocol(memoryTransport);
           return (new Client(prot)).recv_sayHello();
         }
       }
   
     }
   
     public static class Processor<I extends Iface> extends org.apache.thrift.TBaseProcessor<I> implements org.apache.thrift.TProcessor {
       private static final Logger LOGGER = LoggerFactory.getLogger(Processor.class.getName());
       public Processor(I iface) {
         super(iface, getProcessMap(new HashMap<String, org.apache.thrift.ProcessFunction<I, ? extends org.apache.thrift.TBase>>()));
       }
   
       protected Processor(I iface, Map<String,  org.apache.thrift.ProcessFunction<I, ? extends  org.apache.thrift.TBase>> processMap) {
         super(iface, getProcessMap(processMap));
       }
   
       private static <I extends Iface