RPC过程简单实现

骑猪看日落 2021-09-12 06:30 459阅读 0赞

1、主要代码

package com.github.distribute.rpc;
    
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    import java.lang.reflect.InvocationHandler;
    import java.lang.reflect.Method;
    import java.lang.reflect.Proxy;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class RpcFramework {
    
        public static void export(final Object service, final Class interfaceClazz, int port) throws Exception {
            if (service == null) {
                throw new IllegalAccessException("service instance == null");
            }
            if (port < 0 || port > 65535) {
                throw new IllegalAccessException("Invalid port " + port);
            }
            System.out.println("Export service " + service.getClass().getName() + " on port " + port);
    
            ServerSocket server = new ServerSocket(port);
            //循环等待，每来一个请求开启一条线程进行处理
            for (;;) {
                final Socket socket = server.accept();//tcp阻塞等待
                try {
                    new Thread(new Runnable() {
    
                        @Override
                        public void run() {
                            try {
                                try {
                                    ObjectInputStream input = new ObjectInputStream(socket.getInputStream());
    
                                    try {
                                        String interfaceName = input.readUTF();
                                        String methodName = input.readUTF();
                                        Class<?>[] parameterTypes = (Class<?>[]) input.readObject();
                                        Object[] arguments = (Object[]) input.readObject();
                                        ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());
    
                                        try {
                                            if (!interfaceName.equals(interfaceClazz.getName())) {
                                                throw new IllegalAccessException("Interface wrong, export:" + interfaceClazz
                                                        + " refer:" + interfaceName);
                                            }
                                            Method method = service.getClass().getMethod(methodName, parameterTypes);
                                            Object result = method.invoke(service, arguments);
                                            output.writeObject(result);
                                        } catch (Throwable t) {
                                            output.writeObject(t);
                                        } finally {
                                            output.close();
                                        }
                                    }  catch (Throwable t) {
                                    	t.printStackTrace();
                                    } finally {
                                        input.close();
                                    }
                                } 
                                
                                finally {
                                    socket.close();
                                }
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                    }).start();
                } catch (Exception e) {
                    e.printStackTrace();
                }
    
            }
        }
    
        @SuppressWarnings("unchecked")
        public static <T> T refer(final Class<T> interfaceClass, final String host, final int port) throws Exception {
            if (interfaceClass == null) {
                throw new IllegalAccessException("Interface class == null");
            }
            if (!interfaceClass.isInterface()) {
                throw new IllegalAccessException(interfaceClass.getName() + " must be interface");
            }
            if (host == null || host.length() == 0) {
                throw new IllegalAccessException("host == null");
            }
            if (port <= 0 || port > 65535) {
                throw new IllegalAccessException("Invalid port " + port);
            }
            System.out.println("Get remote service " + interfaceClass.getName() + " from server " + host + ":" + port);
            return (T) Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class<?>[] { interfaceClass },
                    new InvocationHandler() {
    
                        @Override
                        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                            // TODO Auto-generated method stub
                            Socket socket = new Socket(host, port);
                            try {
                                ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());
    
                                try {
                                	output.writeUTF(interfaceClass.getName());
                                    output.writeUTF(method.getName());
                                    output.writeObject(method.getParameterTypes());
                                    output.writeObject(args);
    
                                    ObjectInputStream input = new ObjectInputStream(socket.getInputStream());
    
                                    try {
                                        Object result = input.readObject();
                                        if (result instanceof Throwable) {
                                            throw (Throwable) result;
                                        }
                                        return result;
                                    } finally {
                                        input.close();
                                    }
    
                                } finally {
                                    output.close();
                                }
    
                            } finally {
                                socket.close();
                            }
                        }
                    });
        }
    
    }

2、模拟接口

接口类

package com.github.distribute.rpc;
    
    public interface  HelloService {
    	
    	String hello();  
    	  
        String hello(String name);
    
    }

实现类

package com.github.distribute.rpc;
    
    
    public class HelloServiceImpl implements HelloService {  
      
        @Override  
        public String hello() {  
            return "Hello";  
        }  
      
        @Override  
        public String hello(String name) {  
            return "Hello," + name;  
        }  
      
    }

3、接口提供者

package com.github.distribute.rpc;
    
    public class RpcProvider {
    	
    	  public static void main(String[] args) throws Exception {  
    	        HelloService service = new HelloServiceImpl();  
    	        RpcFramework.export(service, HelloService.class, 9000);  
    	    }
    
    }

结果：

![20170505141221584][]

4、消费者

package com.github.distribute.rpc;
    
    public class RpcConsumer {
    	public static void main(String[] args) throws Exception {
    		HelloService service = RpcFramework.refer(HelloService.class, "127.0.0.1", 9000);
    		String result = service.hello("rod");
    		System.out.println(result);
    	}
    
    }

结果：

![20170505141234850][]

[20170505141221584]: /images/20210811/0bb7aa4335744a61adbc5672fa3ee7a5.png
[20170505141234850]: /images/20210811/93e462c703134050a84b846b0468c778.png