Java注解使用MVC控制

1、注解文件

　　a）SocketCommand.java

/**
 * 
 */
package com.example.netty.lesson11.serviceSeparate.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 请求命令
 * @author yangwj
 *
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface SocketCommand {
    
    /**
     * 请求的命令号
     * @return
     */
    short cmd();

}

　　b) SocketModule.java

/**
 * 
 */
package com.example.netty.lesson11.serviceSeparate.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 请求模块
 * @author yangwj
 *
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface SocketModule {
    
    /**
     * 请求的模块号
     * @return
     */
    short module();
}

2、service服务

　　a)UserService.java

package com.example.netty.lesson11.serviceSeparate.service;

import com.example.netty.lesson11.serviceSeparate.annotation.SocketCommand;
import com.example.netty.lesson11.serviceSeparate.annotation.SocketModule;

/**
 * @author yangwj
 * @date 2020/4/6 16:12
 */
@SocketModule(module = 1)
public interface UserService {
    /**
     * 登陆
     */
    @SocketCommand(cmd = 1)
    public void login();

    @SocketCommand(cmd = 2)
    public void getInfo();
}

　　b)UserServiceImpl.java

package com.example.netty.lesson11.serviceSeparate.service.serviceImpl;

import com.example.netty.lesson11.serviceSeparate.service.UserService;
import org.springframework.stereotype.Component;

/**
 * @author yangwj
 * @date 2020/4/6 16:15
 */
@Component
public class UserServiceImpl implements UserService {
    @Override
    public void login() {
        System.out.println("login");
    }

    @Override
    public void getInfo() {
        System.out.println("getInfo");
    }
}

3、执行器Invoker.java

package com.example.netty.lesson11.serviceSeparate;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * 执行器
 * @author yangwj
 * @date 2020/4/6 16:36
 */
public class Invoker {
    /**
     * 目标对象
     */
    private  Object target;

    /**
     * 方法
     */
    private Method method;


    public static Invoker valueOf(Object target,Method method){
        Invoker invoker = new Invoker();
        invoker.setTarget(target);
        invoker.setMethod(method);
        return invoker;
    }

    public Object invoke(Object[] args){
        try {
            method.invoke(target,args);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        return null;
    }


    public Object getTarget() {
        return target;
    }

    public void setTarget(Object target) {
        this.target = target;
    }

    public Method getMethod() {
        return method;
    }

    public void setMethod(Method method) {
        this.method = method;
    }
}

4、执行器管理器InvokerHolder.java

package com.example.netty.lesson11.serviceSeparate;

import java.util.HashMap;
import java.util.Map;

/**
 * 执行器管理者
 * @author yangwj
 * @date 2020/4/6 16:41
 */
public class InvokerHolder {
    public static Map<Short, Map<Short,Invoker>> invokers = new HashMap<>();


    /**
     * 添加一个执行器
     * @param module
     * @param cmd
     * @param invoker
     */
    public static void addInvoker(short module,short cmd ,Invoker invoker){
        Map<Short,Invoker> map = invokers.get(module);
        if(map == null){
            map = new HashMap<>();
            invokers.put(module,map);
        }
        map.put(cmd,invoker);
    }

    public static Invoker getInvoker(short module,short cmd){
        Map<Short,Invoker> map = invokers.get(module);
        if(map != null){
            return map.get(cmd);
        }
        return null;
    }
}

5、注解扫描器

package com.example.netty.lesson11.serviceSeparate;

import com.example.netty.lesson11.serviceSeparate.annotation.SocketCommand;
import com.example.netty.lesson11.serviceSeparate.annotation.SocketModule;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

/**
 * 扫描器
 * @author yangwj
 * @date 2020/4/6 16:16
 */
@Component
public class Scanner implements BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        Class<? extends Object> clazz =  bean.getClass();
        Class<?>[] interfaces =  clazz.getInterfaces();
        if(interfaces != null && interfaces.length >0 ){
            //扫描所有的接口
            for(Class<?> interFace : interfaces){
                SocketModule socketModule = interFace.getAnnotation(SocketModule.class);
                if(socketModule == null){
                    continue;
                }

                Method[] methods = interFace.getMethods();
                if(methods!=null && methods.length>0){
                    for (Method method:methods) {
                        SocketCommand socketCommand = method.getAnnotation(SocketCommand.class);
                        if(socketCommand == null){
                            continue;
                        }
                        short module = socketModule.module();
                        short cmd = socketCommand.cmd();
                        Invoker invoker = Invoker.valueOf(bean,method);
                        if(InvokerHolder.getInvoker(module,cmd) == null){
                            InvokerHolder.addInvoker(module,cmd,invoker);
                        }else {
                            System.out.println("重复注册执行器module:"+ module +"---cmd:"+cmd);
                        }
                    }
                }
            }
        }
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }
}

6、主程序执行

package com.example.netty;

import com.example.netty.lesson11.serviceSeparate.Invoker;
import com.example.netty.lesson11.serviceSeparate.InvokerHolder;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class NettyApplication {

    public static void main(String[] args) {
        SpringApplication.run(NettyApplication.class, args);
        Invoker invoker = InvokerHolder.getInvoker((short)2, (short)1);
        invoker.invoke(null);
    }
}

完毕！

GitHub地址：https://github.com/812406210/Netty-study.git