Thrift 入门Demo Java版本

1.创建thrift文件

新建一个maven项目，定义一个羡慕首先定义一个thrift文件，位置随意

service  HelloWorldService {
  string sayHello(1:string username)
}

这就定义好了一个名字为 HelloWorldService 的服务，后续客户端和服务端代码都是围绕这个HelloWorldService来写的

2.生成thrift代码

切到HelloWorldService.thrift文件所在的跟目录下，在命令行执行H

thrift  -gen java HelloWorldService.thrift

java 表示要生成的是java代码，还可以生成python,c,c++等

以下为HelloWorldService.java的部分代码，主要是Iface和client

 public interface Iface {

    public String sayHello(String username) 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 username) throws org.apache.thrift.TException
    {
      send_sayHello(username);
      return recv_sayHello();
    }

    public void send_sayHello(String username) throws org.apache.thrift.TException
    {
      sayHello_args args = new sayHello_args();
      args.setUsername(username);
      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");
    }

  }

Iface是个接口文件，主要是用来被服务器端的程序继承和重写的，Iface里面定义了方法的接口，在服务器端的程序中应当实现这个接口，而client程序中定义了sayHello 方法，而sayHello 方法中又调用了send_sayHello和 recv_hello 用来发送请求和接受反馈，具体通信的细节不用用户去考虑，thrift已经帮我们完全生成好了，只需要我们具体实现sayhello的方法

3.实现接口

可以新建一个包，名为common，里面存client 和server都会用到的代码,新建HelloWorldImpl 文件用来实现之前生成的接口，这里重写了sayHello方法

package common;

public class HelloWorldImpl implements  HelloWorldService.Iface {
    public  HelloWorldImpl(){
    }
    @Override
    public  String sayHello(String username){
        return "hi " + username +"welcome to thrift world";
    }
}

4.服务端代码

新建 HelloServerDemo java

package server;


import common.HelloWorldImpl;
import common.HelloWorldService;
import org.apache.thrift.TProcessor;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.server.TServer;
import org.apache.thrift.server.TSimpleServer;
import org.apache.thrift.transport.TServerSocket;

public class HelloServerDemo {
    public  static  final int  SERVER_PORT = 8090;
    public void startServer() {
        try {
            System.out.println("HelloWorld TSimpleServer start ....");

            //在这里调用了 HelloWorldImpl 规定了接受的方法和返回的参数
            TProcessor tprocessor = new HelloWorldService.Processor<HelloWorldService.Iface>( new HelloWorldImpl());

            TServerSocket serverTransport = new TServerSocket(SERVER_PORT);
            TServer.Args tArgs = new TServer.Args(serverTransport);
            tArgs.processor(tprocessor);
            tArgs.protocolFactory(new TBinaryProtocol.Factory());

            TServer server = new TSimpleServer(tArgs);
            server.serve();

        } catch (Exception e) {
            System.out.println("Server start error!!!");
            e.printStackTrace();
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        HelloServerDemo server = new HelloServerDemo();
        server.startServer();
    }

}

5.客户端代码

package client;

import common.HelloWorldService;
import org.apache.hadoop.yarn.webapp.example.HelloWorld;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;


public class HelloClientDemo {

    public static final String SERVER_IP = "localhost";
    public static final int SERVER_PORT = 8090;
    public static final int TIMEOUT = 30000;

    /**
     *
     * @param userName
     */
    public void startClient(String userName) {
        TTransport transport = null;
        try {
            transport = new TSocket(SERVER_IP, SERVER_PORT, TIMEOUT);
            // 协议要和服务端一致
            TProtocol protocol = new TBinaryProtocol(transport);

            HelloWorldService.Client client = new HelloWorldService.Client(protocol);
            transport.open();
            String result = client.sayHello(userName);
            System.out.println("Thrify client result =: " + result);
        } catch (TTransportException e) {
            e.printStackTrace();
        } catch (TException e) {
            e.printStackTrace();
        } finally {
            if (null != transport) {
                transport.close();
            }
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        HelloClientDemo client = new HelloClientDemo();
        client.startClient("china");

    }

}

调用HelloWorldService的client即可，client可以调用sayHello方法，向服务器传递参数，并接受服务器返回的信息

6.小结

首先生成了HelloWorldService文件，然后通过HelloWorldImpl实现了HelloWorldService的Iface接口，这个包impl文件只会在服务器端被调用，来规定服务器端返回的信心，而客户端程序只需要调用HelloWorldService中的client
项目目录结构如下