¶ Thrift简介
Apache Thrift 软件框架是开源的跨语言RPC框架，用于可扩展的跨语言服务开发，它将软件堆栈与代码生成引擎相结合，通过中间语言（IDL, 接口定义语言）来定义RPC的接口和数据类型，然后通过一个编译器生成不同语言的代码（C++、Java、Python、PHP、Ruby、Erlang、Perl、Haskell、C#、Cocoa、JavaScript、Node.js、Smalltalk、OCaml 和 Delphi）。
Thrift实际上是实现了C/S模式（客户端/服务器模式），通过代码生成工具将接口定义文件生成服务器端和客户端代码（可以为不同语言），从而实现服务端和客户端跨语言的支持。用户在Thirft描述文件中声明自己的服务，这些服务经过编译后会生成相应语言的代码文件，然后用户实现服务（客户端调用服务，服务器端提服务）便可以了。其中protocol（协议层, 定义数据传输格式，可以为二进制或者XML等）和transport（传输层，定义数据传输方式，可以为TCP/IP传输，内存共享或者文件共享等）被用作运行时库。
¶ Thrift实战
¶ 1 安装
# 使用brew安装thrift
brew install thrift
# 同时安装相关依赖
brew install boost
brew install openssl
brew install libevent
# 最后查看是否成功
thrift -version
¶ 2 编写thrift接口定义文件
# test.thrift
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
¶ 3 根据IDL生成对应的源文件
thrift --gen <language> <Thrift filename>
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
¶ 4 实现接口
package common;
public class HelloWorldImpl implements HelloWorldService.Iface {
public HelloWorldImpl(){
}
@Override
public String sayHello(String username){
return "hi " + username +"welcome to thrift world";
}
}
¶ 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");
}
}
¶ 6 服务端代码
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();
}
}