手写一个简单的 java微服务，带你了解底层

最新推荐文章于 2025-06-11 11:19:06 发布

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本文详细介绍了一个简单的微服务实践过程，包括服务的注册、调用流程，以及如何通过自定义代码实现微服务之间的通信。从注册中心的概念到客户端和服务端的具体实现，为初学者提供了深入理解微服务架构的机会。

在公司里使用微服务后觉得自己不应该只会用。还要了解一下底层的东西。所以就手写了一篇最简单的微服务。作为介绍微服务的开始。代码主要分以下结构

启动顺序：

1.先启动Server服务端

将服务注册到注册中心ReqsterService，并对外暴露服务

2.启动App客户端

即可完成调用。

package io.mytest.service;

import java.util.HashMap;
//注册服务
public class RegsterService {

	public static HashMap<String, Class> regsterService =new HashMap<>();//注册中心

	
	/**
	 * 
	 * @param interfaceName 服务接口名
	 * @param serviceName   服务实现类名
	 */
	public static void regsterService(String interfaceName, Class interfaceImpl){
		System.out.println("注册服务："+interfaceName+"实现服务"+interfaceImpl.getName());
		regsterService.put(interfaceName, interfaceImpl);//注册服务
		
	}
	
	
}

package io.mytest.service;

import java.util.HashMap;
//注册服务
public class RegsterService {

	public static HashMap<String, Class> regsterService =new HashMap<>();//注册中心

	
	/**
	 * 
	 * @param interfaceName 服务接口名
	 * @param serviceName   服务实现类名
	 */
	public static void regsterService(String interfaceName, Class interfaceImpl){
		System.out.println("注册服务："+interfaceName+"实现服务"+interfaceImpl.getName());
		regsterService.put(interfaceName, interfaceImpl);//注册服务
		
	}
	
	
}

package io.mytest.service;

import java.io.Serializable;

public class HelloServiceImpl  implements HelloService,Serializable{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	@Override
	public String sayHello(String name) {
		
		return "尊敬的会员"+name+"您好";
	}

}

package io.mytest.service;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Server {
	//线程处理接收到的请求
	private static ExecutorService executorService = Executors.newFixedThreadPool(10);
	
	@SuppressWarnings("resource")
	public void start(int port){
	//1.注册服务
	RegsterService.regsterService(HelloService.class.getName(), HelloServiceImpl.class);
		
	//2.启动服务

	try {
		final ServerSocket serverSocket = new ServerSocket(port);
		//serverSocket.bind(new InetSocketAddress(port));
		
		while (true) {
			executorService.execute(new Runnable() {
				
				@Override
				public void run() {
					Socket clientScoket =null;
					InputStream inputStream =null;
					ObjectInputStream objectInputStream =null;
					ObjectOutputStream objectOutputStream =null;
					try {
						
						
						clientScoket = serverSocket.accept();
						System.out.println("服务端收到请求");
						OutputStream outputStream = clientScoket.getOutputStream();
						objectOutputStream = new ObjectOutputStream(outputStream);
						inputStream = clientScoket.getInputStream();
						objectInputStream = new ObjectInputStream(inputStream);
						//服务名
						String serviceName = objectInputStream.readUTF();
						//方法名
						String methodName = objectInputStream.readUTF();
						
						Class<?>[] parameterTypes = (Class<?>[]) objectInputStream.readObject();
						
						Object[] args = (Object[]) objectInputStream.readObject();
						//查找服务
						
						Class<?> serviceClass = RegsterService.regsterService.get(serviceName);
						
						
						if (serviceClass==null) {
							throw new ClassNotFoundException("服务未找到"+serviceName);
							
						}
						//System.out.println("name"+serviceName);
						Method method = serviceClass.getMethod(methodName, parameterTypes);
						
						
						Object result = method.invoke(serviceClass.newInstance(), args);
						
						System.out.println("服务端打印结果"+(String)result);
						objectOutputStream.writeObject(result);
						
					} catch (Exception  e) {
						e.printStackTrace();
					}finally{
						
						try {
							
							objectOutputStream.close();
							objectInputStream.close();
							clientScoket.close();
							
						} catch (IOException e1) {
							
							e1.printStackTrace();
						}
						
						
						
					}
					
				}
			});
			
			
			
			
			
		}
		
	} catch (IOException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
		
		
		
	}
	
	
	public static void main(String[] args) {
		
		Server server = new Server();
		
		server.start(8082);
		System.out.println("服务启动");
		
	}

}

package io.mytest.service;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.net.Socket;


public class Client {
	
	
	@SuppressWarnings("unchecked")
	public static <T> T getClient(final Class interfaceClass ,final String host,final int port){
		
		
		T  t =(T) Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class[]{interfaceClass}, new InvocationHandler() {
			
			@Override
			public Object invoke(Object proxy, Method method, Object[] args)
					throws Throwable {
				
				Socket socket =null;
				InputStream inputStream =null;
				ObjectInputStream objectInputStream =null;
				ObjectOutputStream objectOutputStream =null;
				try {
					socket = new Socket(host, port);
					OutputStream outputStream = socket.getOutputStream();
					objectOutputStream = new ObjectOutputStream(outputStream);
					inputStream = socket.getInputStream();
					objectInputStream = new ObjectInputStream(inputStream);
					
					//服务名
					String serviceName = interfaceClass.getName();
					//方法名
					String methodName = method.getName();
					//方法的参数类型
					Class<?>[] parameterTypes = method.getParameterTypes();
					//方法参数 args
					
					objectOutputStream.writeUTF(serviceName);
					objectOutputStream.writeUTF(methodName);
					
					objectOutputStream.writeObject(parameterTypes);
					objectOutputStream.writeObject(args);
					
					Object readObject = objectInputStream.readObject();
					
					return readObject;
					
				} catch (Exception e) {
					
					e.printStackTrace();
				}finally{
					

					try {
						objectInputStream.close();
						objectOutputStream.close();
						socket.close();
					} catch (IOException e) {
					
						e.printStackTrace();
					}
				}
				
				return null;
			}
		});
		
		return t;
	}

}

package io.mytest.service;

public class App {
	
	public static void main(String[] args) {
		System.out.println("客户端调用开始");
		HelloService client = Client.getClient(HelloService.class, "192.168.20.123", 8082);
		System.out.println(client.sayHello("测试人员"));
		System.out.println("客户端调用结束");
	}

}