学习Facebook Thrift笔记
相关资料参考链接：
http://incubator.apache.org/thrift/
http://wiki.apache.org/thrift/FrontPage
http://jnb.ociweb.com/jnb/jnbJun2009.html 非常好的入门教程
http://developers.facebook.com/thrift/thrift-20070401.pdf thrift开发者写的论文
Thrift是个啥东东？
来自wiki.apache.org/thrift/FrontPage的定义
Thrift is a software framework for scalable cross-language services development.
Thrift是为了实现跨语言服务访问的一个框架
Thrift allows you to define data types and service interfaces in a simple definition file.
Thrift定义了数据和服务的描述方式，是一种IDL
Taking that file as input, the compiler generates code to be used to easily build RPC clients and servers that communicate seamlessly across programming languages.
写一个定义文件，就可以使用thrift来生成某种语言RPC客户端和服务端程序框架。你只需要考虑如何实现你的服务就可以了。并且它支持很多种语言。
这有点像web service, 定义好一个web service服务描述文件后，可以使用如axis等工具生成服务器端或客户端的框架程序。
为什么还需要Thrift
thrift-20070401.pdf中有解释。
1、多语言开发的需要
比如其中提到的搜索服务，LAMP本身没有这个功能，开发者可能使用C++开发，php如何访问这个服务呢？于是需要有一种高效的跨语言访问的方法。
2、性能问题
web service也可以实现多语言互访问的功能，但xml文件太大，性能不行。Thrift可以使用二进值的格式。
开始测试
实现一个简单的服务，就是根据loginName得到User, user中有userId,loginName, name, password
第一步，写Thrift IDL文件 ，user.thrift，
namespace java mytest.thrift.gen
namespace py mytest.thrift
struct User {
1: i32 userId,
2: string loginName,
3: string password,
4: string name
}
exception UserNotFound {
1: string message
}
service UserService {
User getUser(1:string loginName) throws (1:UserNotFound unf),
list<User> getUsers()
}
第二步，生成java和python代码
thrift --gen java user.thrift
thrift --gen py user.thrift
第三步，实现java服务端
参见：http://wiki.apache.org/thrift/ThriftUsageJava
服务短的处理类实现 UserServiceHandler.java
package myserver;
import java.util.ArrayList;
import java.util.List;
import mytest.thrift.gen.User;
import mytest.thrift.gen.UserNotFound;
import mytest.thrift.gen.UserService;
import org.apache.thrift.TException;
public class UserServiceHandler implements UserService.Iface {
@Override
public User getUser(String loginName) throws UserNotFound, TException {
if (!"login1".equals(loginName)) {
UserNotFound e = new UserNotFound("User not Found!");
throw e;
}
User user = new User();
user.setUserId(100);
user.setLoginName("login1");
user.setPassword("pwd1");
user.setName("user1");
return user;
}
@Override
public List<User> getUsers() throws TException {
List<User> list = new ArrayList<User>();
User user = new User();
user.setUserId(100);
user.setLoginName("login1");
user.setPassword("pwd1");
user.setName("user1");
list.add(user);
User user2 = new User();
user2.setUserId(200);
user2.setLoginName("login2");
user2.setPassword("pwd2");
user2.setName("user2");
list.add(user2);
return list;
}
}
服务端主程序 Server.java
package myserver;
import mytest.thrift.gen.UserService;
import org.apache.thrift.server.TServer;
import org.apache.thrift.server.TSimpleServer;
import org.apache.thrift.transport.TServerSocket;
import org.apache.thrift.transport.TServerTransport;
public class Server {
public static void main(String[] args) {
try {
UserServiceHandler handler = new UserServiceHandler();
UserService.Processor processor = new UserService.Processor(handler);
TServerTransport serverTransport = new TServerSocket(9090);
TServer server = new TSimpleServer(processor, serverTransport);
// Use this for a multithreaded server
// server = new TThreadPoolServer(processor, serverTransport);
System.out.println("Starting the server...");
server.serve();
} catch (Exception x) {
x.printStackTrace();
}
System.out.println("done.");
}
}
第四步，实现java客户端
package myclient;
import java.util.Iterator;
import java.util.List;
import mytest.thrift.gen.User;
import mytest.thrift.gen.UserNotFound;
import mytest.thrift.gen.UserService;
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;
public class Client {
public static void main(String[] args) {
try {
TTransport transport = new TSocket("localhost", 9090);
TProtocol protocol = new TBinaryProtocol(transport);
UserService.Client client = new UserService.Client(protocol);
transport.open();
System.out.println("test1");
try {
User user1 = client.getUser("login1");
System.out.println("name=" + user1.getName());
} catch (UserNotFound e) {
System.out.println(e.getMessage());
}
System.out.println("test2");
try {
User user2 = client.getUser("login10");
System.out.println("name=" + user2.getName());
} catch (UserNotFound e) {
System.out.println(e.getMessage());
}
System.out.println("test3");
List<User> list = client.getUsers();
Iterator<User> it = list.iterator();
while(it.hasNext()){
User u = it.next();
System.out.println("name=" + u.getName());
}
transport.close();
} catch (TException x) {
x.printStackTrace();
}
}
}
from mytest.thrift import UserService
from mytest.thrift.ttypes import UserNotFound
from thrift import Thrift
from thrift.transport import TSocket
from thrift.transport import TTransport
from thrift.protocol import TBinaryProtocol
try:
# Make socket
transport = TSocket.TSocket('localhost', 9090)
# Buffering is critical. Raw sockets are very slow
transport = TTransport.TBufferedTransport(transport)
# Wrap in a protocol
protocol = TBinaryProtocol.TBinaryProtocol(transport)
# Create a client to use the protocol encoder
client = UserService.Client(protocol)
# Connect!
transport.open()
try:
user1 = client.getUser("login1")
print user1.name
except UserNotFound, io:
print '%r' % io
# Close!
transport.close()
except Thrift.TException, tx:
print '%s' % (tx.message)