Java行为型模式中命令模式分析

//抽象命令
public interface Command {
    void execute();
    void undo();
}
//调用者
class Invoker{
    private Command command;
    public Invoker(Command command) {
        this.command = command;
    }
    public void setCommand(Command command) {
        this.command = command;
    }
    public void call(){
        command.execute();
        command.undo();
    }
}
//具体命令
class insertCommand implements Command {
    private TextField textField;
    private String insertStr = "insertStr";
    public insertCommand(TextField textField) {
        this.textField = textField;
    }
    @Override
    public void execute() {
        textField.text += insertStr;
        System.out.println(textField.text);
    }
    @Override
    public void undo() {
        textField.text = textField.text.substring(0, textField.text.length() - insertStr.length());
        System.out.println(textField.text);
    }
}
//具体命令
class CopyCommand implements Command {
    private TextField textField;
    public CopyCommand(TextField textField) {
        this.textField = textField;
    }
    @Override
    public void execute() {
        textField.text += textField.text;
        System.out.println(textField.text);
    }
    @Override
    public void undo() {
        textField.text = textField.text.substring(0, textField.text.length() / 2);
        System.out.println(textField.text);
    }
}
//接收者
class TextField {
    public String text = "text";
}

public class Client {
    public static void main(String[] args) {
        Invoker invoker = new Invoker(new CopyCommand(new TextField()));
        invoker.call();
    }
}

//具体命令
class ConcreteCommand implements Runnable{
    private Receiver receiver;
    public ConcreteCommand(Receiver receiver) {
        this.receiver = receiver;
    }
    @Override
    public void run() {
        receiver.execute();
    }
}
//接收者
class Receiver{
    public void execute(){
        System.out.println("执行逻辑");
    }
}