Thrift笔记(六)--单端口 多服务

多个服务，使用监听一个端口。先上一个demo

Test.thrift

namespace java com.gxf.thrift

enum RequestType {
   SAY_HELLO,   //问好
   QUERY_TIME,  //询问时间
}

struct Request {
   1: required RequestType type;  // 请求的类型，必选
   2: required string name;       // 发起请求的人的名字，必选
   3: optional i32 age;           // 发起请求的人的年龄，可选
}

exception RequestException {
   1: required i32 code;
   2: optional string reason;
}

// 服务名
service HelloWordService {
   string doAction(1: Request request) throws (1:RequestException qe); // 可能抛出异常。
}

//乘法
service MultiSerivce{
    i32 multi(1:i32 n1, 2:i32 n2);
}

定义了两个服务，一个是hello，一个是mult。第一输出hello信息，第二个做乘法运算。使用thrift命令，生成java代码

thrift -gen java Test.thrift

Server端，两个服务实现类

import org.apache.commons.lang3.StringUtils;

import java.util.Date;

public class HelloWordServiceImpl implements HelloWordService.Iface {

    // 实现这个方法完成具体的逻辑。
    public String doAction(Request request)
            throws RequestException, org.apache.thrift.TException {
        System.out.println("Get request: " + request);
        if (StringUtils.isBlank(request.getName()) || request.getType() == null) {
            throw new com.gxf.thrift.RequestException();
        }
        String result = "Hello, " + request.getName();
        if (request.getType() == com.gxf.thrift.RequestType.SAY_HELLO) {
            result += ", Welcome!";
        } else {
            result += ", Now is " + new Date().toLocaleString();
        }
        return result;

    }
}

import org.apache.thrift.TException;

public class MultiServiceImpl implements MultiSerivce.Iface {
    @Override
    public int multi(int n1, int n2) throws TException {
        return n1 + n2;
    }
}

Service端服务启动类

import org.apache.thrift.TMultiplexedProcessor;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.server.TServer;
import org.apache.thrift.server.TThreadPoolServer;
import org.apache.thrift.transport.TServerSocket;

import java.net.ServerSocket;

public class HelloWordServer {

    public static void main(String[] args) throws Exception {
        ServerSocket socket = new ServerSocket(7912);
        TServerSocket serverTransport = new TServerSocket(socket);
        TBinaryProtocol.Factory proFactory = new TBinaryProtocol.Factory();

        TMultiplexedProcessor multiplexedProcessor = new TMultiplexedProcessor();
        multiplexedProcessor.registerProcessor("helloService", new HelloWordService.Processor<>(
                new HelloWordServiceImpl()));
        multiplexedProcessor.registerProcessor("multiService", new MultiSerivce.Processor<>(
                new MultiServiceImpl()
        ));

       
        TThreadPoolServer.Args serverArgs = new TThreadPoolServer.Args(serverTransport);
        serverArgs.processor(multiplexedProcessor);
        serverArgs.protocolFactory(proFactory);
        TServer server = new TThreadPoolServer(serverArgs);
        System.out.println("Start server on port 7912...");

        server.serve();
    }

}

Client端测试类

import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TMultiplexedProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;

public class HelloWordClient {
    public static void main(String[] args) throws Exception {
        TTransport transport = new TSocket("127.0.0.1", 7912);

        TProtocol protocol = new TBinaryProtocol(transport);
        TMultiplexedProtocol tMultiplexedProtocol = new TMultiplexedProtocol(protocol, "multiService");
        transport.open();
        MultiSerivce.Client multiClient = new MultiSerivce.Client(tMultiplexedProtocol);
        int mulRes = multiClient.multi(1, 3);
        System.out.println("mulRes = " + mulRes);

        TMultiplexedProtocol helloProtocol = new TMultiplexedProtocol(protocol, "helloService");
        HelloWordService.Client helloClient = new HelloWordService.Client(helloProtocol);
        Request helloRequest = new Request();
        helloRequest.setAge(28);
        helloRequest.setName("guanxiangfei");
        helloRequest.setType(RequestType.QUERY_TIME);
        String helloRes = helloClient.doAction(helloRequest);
        System.out.println("helloRes: " + helloRes);


        transport.close();  // 请求结束，断开连接
    }

}

下面主要分析Server端源码

跟进TMultiplexedProcessor类

public class TMultiplexedProcessor implements TProcessor {

    private final Map<String,TProcessor> SERVICE_PROCESSOR_MAP
            = new HashMap<String,TProcessor>();
    private TProcessor defaultProcessor;

这里有个map存放 servicename --> processor，接着看注册源码

public void registerProcessor(String serviceName, TProcessor processor) {
        SERVICE_PROCESSOR_MAP.put(serviceName, processor);
    }

直接在map中放了servicename --> processor。我们跟进serve方法

public void serve() {
    try {
      serverTransport_.listen();
    } catch (TTransportException ttx) {
      LOGGER.error("Error occurred during listening.", ttx);
      return;
    }

    // Run the preServe event
    if (eventHandler_ != null) {
      eventHandler_.preServe();
    }

    setServing(true);

    while (!stopped_) {
      TTransport client = null;
      TProcessor processor = null;
      TTransport inputTransport = null;
      TTransport outputTransport = null;
      TProtocol inputProtocol = null;
      TProtocol outputProtocol = null;
      ServerContext connectionContext = null;
      try {
        client = serverTransport_.accept();
        if (client != null) {
          processor = processorFactory_.getProcessor(client);
          inputTransport = inputTransportFactory_.getTransport(client);
          outputTransport = outputTransportFactory_.getTransport(client);
          inputProtocol = inputProtocolFactory_.getProtocol(inputTransport);
          outputProtocol = outputProtocolFactory_.getProtocol(outputTransport);
          if (eventHandler_ != null) {
            connectionContext = eventHandler_.createContext(inputProtocol, outputProtocol);
          }
          while (true) {
            if (eventHandler_ != null) {
              eventHandler_.processContext(connectionContext, inputTransport, outputTransport);
            }
            if(!processor.process(inputProtocol, outputProtocol)) {
              break;
            }
          }
        }
      } catch (TTransportException ttx) {
        // Client died, just move on
      } catch (TException tx) {
        if (!stopped_) {
          LOGGER.error("Thrift error occurred during processing of message.", tx);
        }
      } catch (Exception x) {
        if (!stopped_) {
          LOGGER.error("Error occurred during processing of message.", x);
        }
      }

      if (eventHandler_ != null) {
        eventHandler_.deleteContext(connectionContext, inputProtocol, outputProtocol);
      }

      if (inputTransport != null) {
        inputTransport.close();
      }

      if (outputTransport != null) {
        outputTransport.close();
      }

    }
    setServing(false);
  }

有个accept接收到客户端连接，重点看

if(!processor.process(inputProtocol, outputProtocol)) {
              break;
            }

这里是处理客户断传来的请求，继续跟进

@Override
  public boolean process(TProtocol in, TProtocol out) throws TException {
    TMessage msg = in.readMessageBegin();
    ProcessFunction fn = processMap.get(msg.name);
    if (fn == null) {
      TProtocolUtil.skip(in, TType.STRUCT);
      in.readMessageEnd();
      TApplicationException x = new TApplicationException(TApplicationException.UNKNOWN_METHOD, "Invalid method name: '"+msg.name+"'");
      out.writeMessageBegin(new TMessage(msg.name, TMessageType.EXCEPTION, msg.seqid));
      x.write(out);
      out.writeMessageEnd();
      out.getTransport().flush();
      return true;
    }
    fn.process(msg.seqid, in, out, iface);
    return true;
  }

获取客户端的请求类型和方法，获取服务端注册的service。跟进fn.process()看服务端处理过程

public final void process(int seqid, TProtocol iprot, TProtocol oprot, I iface) throws TException {
    T args = getEmptyArgsInstance();
    try {
      args.read(iprot);
    } catch (TProtocolException e) {
      iprot.readMessageEnd();
      TApplicationException x = new TApplicationException(TApplicationException.PROTOCOL_ERROR, e.getMessage());
      oprot.writeMessageBegin(new TMessage(getMethodName(), TMessageType.EXCEPTION, seqid));
      x.write(oprot);
      oprot.writeMessageEnd();
      oprot.getTransport().flush();
      return;
    }
    iprot.readMessageEnd();
    TSerializable result = null;
    byte msgType = TMessageType.REPLY;

    try {
      result = getResult(iface, args);
    } catch (TTransportException ex) {
      LOGGER.error("Transport error while processing " + getMethodName(), ex);
      throw ex;
    } catch (TApplicationException ex) {
      LOGGER.error("Internal application error processing " + getMethodName(), ex);
      result = ex;
      msgType = TMessageType.EXCEPTION;
    } catch (Exception ex) {
      LOGGER.error("Internal error processing " + getMethodName(), ex);
      if(!isOneway()) {
        result = new TApplicationException(TApplicationException.INTERNAL_ERROR,
            "Internal error processing " + getMethodName());
        msgType = TMessageType.EXCEPTION;
      }
    }

    if(!isOneway()) {
      oprot.writeMessageBegin(new TMessage(getMethodName(), msgType, seqid));
      result.write(oprot);
      oprot.writeMessageEnd();
      oprot.getTransport().flush();
    }
  }

接着跟进getResult方法，看下服务端如何计算结果

public multi_result getResult(I iface, multi_args args) throws org.apache.thrift.TException {
        multi_result result = new multi_result();
        result.success = iface.multi(args.n1, args.n2);
        result.setSuccessIsSet(true);
        return result;
      }

这里可以看出，调用了服务端实现类对象对应的方法。保存在multi_result对象中，序列化发给客户端。

总结：

单端口，多服务，主要就是用一个map放service-->processor映射。客户端传servicename给服务端