1. 命令接收者接口或抽象定义

public interface IReceiver {
    void doSomething();
}

2. 命令接收者接口或抽象定义实现类

public class ConcreteReceiver implements IReceiver {
    @Override
    public void doSomething() {
        //具体业务逻辑处理
    }
}

3. 命令接口或抽象定义

public interface ICommand {
    void execute();
}

4. 命令接口或抽象定义实现类

public class ConcreteCommand implements ICommand {
    private IReceiver receiver;
    public ConcreteCommand(IReceiver receiver) {
        this.receiver = receiver;
    }
    @Override
    public void execute() {
        this.receiver.doSomething();
    }
}

5. 命令调用者

public class Invoker {
    private ICommand command;
    public void setCommand(ICommand command){
        this.command = command;
    }
    public void action(){
        this.command.execute();
    }
}

6. 场景使用

    //命令调用者
    Invoker invoker = new Invoker();
    //命令接收者
    IReceiver receiver = new ConcreteReceiver();
    //命令
    ICommand command = new ConcreteCommand(receiver);
    //执行命令
    invoker.setCommand(command);
    invoker.action();