Car/Transmission.java

package com.automobile.parts;

/**
 * 变速箱类 - 与汽车是组合关系
 * 变速箱与引擎和车轮之间也存在关联关系
 */
public class Transmission {
    private String type;
    private int gearCount;
    private int currentGear;
    private boolean automatic;
    
    /**
     * 构造方法 - 创建变速箱时设置默认属性
     */
    public Transmission() {
        this.type = "自动变速箱";
        this.gearCount = 6;
        this.currentGear = 0; // 空挡
        this.automatic = true;
    }
    
    /**
     * 根据速度换挡
     * @param speed 当前速度（km/h）
     */
    public void shiftGears(int speed) {
        int newGear;
        
        if (speed == 0) {
            newGear = 0; // 空挡
        } else if (speed <= 20) {
            newGear = 1;
        } else if (speed <= 40) {
            newGear = 2;
        } else if (speed <= 60) {
            newGear = 3;
        } else if (speed <= 80) {
            newGear = 4;
        } else if (speed <= 120) {
            newGear = 5;
        } else {
            newGear = 6;
        }
        
        if (newGear != currentGear) {
            this.currentGear = newGear;
            System.out.println("变速箱换挡到 " + getGearName(currentGear));
        }
    }
    
    /**
     * 获取档位名称
     * @param gear 档位号
     * @return 档位名称
     */
    private String getGearName(int gear) {
        switch (gear) {
            case 0: return "空挡(N)";
            case 1: return "1档";
            case 2: return "2档";
            case 3: return "3档";
            case 4: return "4档";
            case 5: return "5档";
            case 6: return "6档";
            default: return "未知档位";
        }
    }
    
    /**
     * 手动换挡（模拟手动模式）
     * @param gear 目标档位
     */
    public void manualShift(int gear) {
        if (gear >= 0 && gear <= gearCount) {
            this.currentGear = gear;
            System.out.println("手动换挡到 " + getGearName(gear));
        } else {
            System.out.println("无效的档位选择");
        }
    }
    
    /**
     * 切换到倒挡
     */
    public void reverse() {
        this.currentGear = -1;
        System.out.println("切换到倒挡(R)");
    }
    
    // Getter 和 Setter 方法
    public String getType() {
        return type;
    }
    
    public void setType(String type) {
        this.type = type;
    }
    
    public int getGearCount() {
        return gearCount;
    }
    
    public void setGearCount(int gearCount) {
        this.gearCount = gearCount;
    }
    
    public int getCurrentGear() {
        return currentGear;
    }
    
    public boolean isAutomatic() {
        return automatic;
    }
    
    public void setAutomatic(boolean automatic) {
        this.automatic = automatic;
    }
}