Car/Engine.java

package com.automobile.parts;

import java.util.ArrayList;
import java.util.List;

/**
 * 引擎类 - 与汽车是组合关系
 * 引擎包含活塞等部件，展示更深层级的组合关系
 */
public class Engine {
    private String type;
    private int cylinders;
    private int horsepower;
    private int currentRPM;
    private boolean isRunning;
    
    // 组合关系 - 引擎包含多个活塞
    private List<Piston> pistons;
    
    /**
     * 构造方法 - 创建引擎时同时创建活塞
     * 体现了多层级组合关系
     */
    public Engine() {
        this.type = "四缸涡轮增压";
        this.cylinders = 4;
        this.horsepower = 200;
        this.currentRPM = 0;
        this.isRunning = false;
        
        // 创建活塞（组合关系）
        this.pistons = new ArrayList<>();
        for (int i = 0; i < cylinders; i++) {
            this.pistons.add(new Piston(i + 1));
        }
    }
    
    /**
     * 启动引擎
     */
    public void start() {
        if (!isRunning) {
            isRunning = true;
            currentRPM = 800; // 怠速转速
            System.out.println("引擎启动成功，当前转速: " + currentRPM + " RPM");
            // 启动所有活塞
            for (Piston piston : pistons) {
                piston.move();
            }
        } else {
            System.out.println("引擎已经在运行中");
        }
    }
    
    /**
     * 停止引擎
     */
    public void stop() {
        if (isRunning) {
            isRunning = false;
            currentRPM = 0;
            System.out.println("引擎已停止");
            // 停止所有活塞
            for (Piston piston : pistons) {
                piston.stop();
            }
        } else {
            System.out.println("引擎已经停止");
        }
    }
    
    /**
     * 增加转速
     * @param rpm 目标转速
     */
    public void increaseRPM(int rpm) {
        if (isRunning) {
            currentRPM = rpm;
            System.out.println("引擎转速提升到: " + currentRPM + " RPM");
            // 所有活塞加速运动
            for (Piston piston : pistons) {
                piston.moveFaster(rpm);
            }
        } else {
            System.out.println("请先启动引擎");
        }
    }
    
    // Getter 和 Setter 方法
    public String getType() {
        return type;
    }
    
    public void setType(String type) {
        this.type = type;
    }
    
    public int getCylinders() {
        return cylinders;
    }
    
    public void setCylinders(int cylinders) {
        this.cylinders = cylinders;
        // 重新创建对应数量的活塞
        this.pistons = new ArrayList<>();
        for (int i = 0; i < cylinders; i++) {
            this.pistons.add(new Piston(i + 1));
        }
    }
    
    public int getHorsepower() {
        return horsepower;
    }
    
    public void setHorsepower(int horsepower) {
        this.horsepower = horsepower;
    }
    
    public int getCurrentRPM() {
        return currentRPM;
    }
    
    public boolean isRunning() {
        return isRunning;
    }
    
    public List<Piston> getPistons() {
        return pistons;
    }
}