Facebook/Swift：简化Java中Thrift开发的工具

用Thrift在java中开发过的同学都了解，使用Thrift的IDL语言生成的java文件是无比巨大和复杂的。很多时候对这样一种超大的实体和service定义都感到非常无力。增减方法，增减字段的文件替换都非常不方便。还好发现了一个简化开发的工具，Facebook/Swift，github地址：https://github.com/facebook/swift
这个框架的核心原理是通过定义和实现注解来达到简化Thrift文件的目的，使得在开发时定义的POJO和Interface都能够和普通的java文件一致；
我们直接看例子，我们定义一个实体类，可以简化写法是：

@ThriftStruct
public class ThirdPartyCollection {

    public final long id; // required
    public final String date; // optional

    @ThriftConstructor
    public ThirdPartyCollection(long id, String date) {
        this.id = id;
        this.date = date;
    }
    @ThriftField(1)
    public long getId() {
        return id;
    }
    @ThriftField(2)
    public String getDate() {
        return date;
    }    

这要比直接使用thrift IDL生成的java代码简单非常多的倍数；
定义service写法如下：

@ThriftService("ThirdPartyCollectionService")
public interface ThirdPartyCollectionService {
    @ThriftMethod
    public ThirdPartyCollection save(@ThriftField(name = "collection") ThirdPartyCollection collection) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException;
    @ThriftMethod
    public ThirdPartyCollection update(@ThriftField(name = "collection") ThirdPartyCollection collection);
    @ThriftMethod
    public List<ThirdPartyCollection> getAll();
}

写法需要在类和方法以及方法参数增加注解即可。
同时，启动服务和client调用的代码也有所变动：

public static void main(String[] args) throws IOException, InterruptedException {
        ThriftServiceProcessor processor = new ThriftServiceProcessor(
                new ThriftCodecManager(),
                ImmutableList.<ThriftEventHandler>of(),
                new ThirdPartyCollectionServiceImpl()
        );

        taskWorkerExecutor = newFixedThreadPool(1);

        ThriftServerDef serverDef = ThriftServerDef.newBuilder()
                .listen(8899)
                .withProcessor(processor)
                .using(taskWorkerExecutor)
                .build();

        bossExecutor = newCachedThreadPool();
        ioWorkerExecutor = newCachedThreadPool();

        NettyServerConfig serverConfig = NettyServerConfig.newBuilder()
                .setBossThreadExecutor(bossExecutor)
                .setWorkerThreadExecutor(ioWorkerExecutor)
                .build();

        server = new ThriftServer(serverConfig, serverDef);
        server.start();
}

Client端调用代码：

public static void main(String[] args) throws ExecutionException, InterruptedException, IllegalAccessException, NoSuchMethodException, InvocationTargetException {
        ThriftClientManager clientManager = new ThriftClientManager();
        FramedClientConnector connector = new FramedClientConnector(new InetSocketAddress("localhost",8899));
        ThirdPartyCollectionService scribe = clientManager.createClient(connector, ThirdPartyCollectionService.class).get();
        scribe.getAll();
        com.qiyi.thrift.test.core.ThirdPartyCollection collection =
                new com.qiyi.thrift.test.core.ThirdPartyCollection(1001, "2014-08-29");
        scribe.save(collection);
}