Hadoop 日常学习bug调试(二)_exception in thread "main" java.lang.runtimeexcept

RPC的使用

代码如下：

LoginServiceInterface.java

package rpc;
 
public interface LoginServiceInterface
{
    public static final long versionID=1L;
    public String login(String userName,String pwd);
}

注意该接口versionID版本号必须设置，否则客户端调用时报错

Exception in thread "main" java.lang.RuntimeException: java.lang.NoSuchFieldException: versionID
	at org.apache.hadoop.ipc.RPC.getProtocolVersion(RPC.java:179)
	at org.apache.hadoop.ipc.WritableRpcEngine$Invocation.<init>(WritableRpcEngine.java:113)
	at org.apache.hadoop.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:252)
	at com.sun.proxy.$Proxy4.login(Unknown Source)
	at rpc.LoginController.main(LoginController.java:18)
Caused by: java.lang.NoSuchFieldException: versionID
	at java.lang.Class.getField(Class.java:1703)
	at org.apache.hadoop.ipc.RPC.getProtocolVersion(RPC.java:175)
	... 4 more

LoginServiceImpl.java

package rpc;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
public class LoginServiceImpl implements LoginServiceInterface
{
    private static final Logger logger = LoggerFactory.getLogger(LoginServiceImpl.class);
 
    @Override
    public String login(String userName, String pwd)
    {
        return userName + " logged in successfully!";
    }
}

服务端启动 Starter.java

package rpc;
 
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.ipc.RPC;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
import java.io.IOException;
 
public class Starter
{
    private static final Logger logger = LoggerFactory.getLogger(Starter.class);
 
    public static void main(String[] args) throws IOException
    {
        RPC.Builder builder = new RPC.Builder(new Configuration());
        builder.setBindAddress("192.168.1.103").setPort(10000).setProtocol(LoginServiceInterface.class).setInstance(new LoginServiceImpl());
        RPC.Server server = builder.build();
        server.start();
    }
}

客户端启动LoginController.java

package rpc;
 
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.ipc.RPC;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
import java.io.IOException;
import java.net.InetSocketAddress;
 
public class LoginController
{
    private static final Logger logger = LoggerFactory.getLogger(LoginController.class);
 
    public static void main(String[] args) throws IOException
    {
        LoginServiceInterface loginServiceInterface = RPC.getProxy(LoginServiceInterface.class, 1L, new InetSocketAddress("192.168.1.103",10000), new Configuration());
        String result = loginServiceInterface.login("xuliang", "123");
        logger.debug("result: " + result);
    }
}

客户端运行结果：

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