java基础教程栏目介绍有帮助的Java中封装和继承的案例
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一、代码及效果图
1.封装
案例：需求说明
使用封装实现电子宠物系统的企鹅类正确输入健康值和亲密度
保证健康值的有效性（0-100），否则取默认值60
保证亲密度的有效性（0-100），否则取默认值60
代码如下（示例）：
package work1;public class Dog { private String name; private String sex; private int love; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(int sex) { if(sex==1){ this.sex = "Q仔"; }else{ this.sex = "Q妹"; } } public int getLove() { return love; } public void setLove(int love) { if(love>=0&&love<=100){ this.love = love; }else { System.out.println("亲密度应该在0-100之间，默认值是60"); this.love = 60; } }}
package work1;public class Penguin { private String name; private String sex; private int health; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(int sex) { if(sex==1){ this.sex = "Q仔"; }else{ this.sex = "Q妹"; } } public int getHealth() { return health; } public void setHealth(int health) { if(health>=0&&health<=100){ this.health = health; }else { System.out.println("健康值应该在0-100之间，默认值是60"); this.health = 60; } }}
package work1;import java.util.Scanner;public class Test1 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("欢迎您来到宠物店! \n 请输入要领养宠物的名字："); String name = sc.next(); System.out.println("请选择要领养的宠物类型：（1.狗狗 2.企鹅）"); int i = sc.nextInt(); if(i==1){//狗狗 Dog dog = new Dog(); dog.setName(name); System.out.println("请选择狗狗的性别：(1.Q仔 2.Q妹)"); dog.setSex(sc.nextInt()); System.out.println("请输入狗狗的亲密度（1~100之间）："); dog.setLove(sc.nextInt()); System.out.println("宠物的自白：\n 我的名字叫"+name+",健康值是"+0+",和主人的" + "亲密度是"+dog.getLove()+",我的性别是"+dog.getSex()); }else {//企鹅 Penguin p = new Penguin(); p.setName(name); System.out.println("请选择企鹅的性别：(1.Q仔 2.Q妹)"); p.setSex(sc.nextInt()); System.out.println("请输入企鹅的健康值（1~100之间）："); p.setHealth(sc.nextInt()); System.out.println("宠物的自白：\n 我的名字叫"+name+",健康值是"+p.getHealth()+",和主人的" + "亲密度是"+0+",我的性别是"+p.getSex()); } }}
2.继承
案例：使用继承优化电子宠物系统，抽取父类，创建子类，在子类中使用super调用父类构造方法。
代码如下（示例）：
package work3;public class Dog extends Pet { @Override public void show() { System.out.println("宠物的自白：\n 我的名字叫"+this.getName()+",健康值是"+0+",和主人的" + "亲密度是"+this.getLove()+",我的性别是"+this.getSex()); } private int love; public Dog(String name, int sex, int love) { super(name, sex); this.love = love; } public int getLove() { return love; } public void setLove(int love) { if(love>=0&&love<=100){ this.love = love; }else { System.out.println("亲密度应该在0-100之间，默认值是60"); this.love = 60; } }}
package work3;public class Penguin extends Pet { @Override public void show() { System.out.println("宠物的自白：\n 我的名字叫"+this.getName()+",健康值是"+this.getHealth()+",和主人的" + "亲密度是"+0+",我的性别是"+this.getSex()); } private int health; public Penguin(String name, int sex, int health) { super(name, sex); this.health = health; } public int getHealth() { return health; } public void setHealth(int health) { if(health>=0&&health<=100){ this.health = health; }else { System.out.println("健康值应该在0-100之间，默认值是60"); this.health = 60; } }}
package work3;public class Pet { private String name; private String sex; public void show(){ } public Pet(String name, int sex) { this.name = name; if(sex==1){ this.sex = "Q仔"; }else{ this.sex = "Q妹"; } } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(int sex) { if(sex==1){ this.sex = "Q仔"; }else{ this.sex = "Q妹"; } }}
package work3;import java.util.Scanner;import static java.lang.System.out;public class Test2 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); out.println("欢迎您来到宠物店! \n 请输入要领养宠物的名字："); String name = sc.next(); out.println("请选择要领养的宠物类型：（1.狗狗 2.企鹅）"); int i = sc.nextInt(); if (i==1){//狗狗 out.println("请选择狗狗的性别：(1.Q仔 2.Q妹)"); int sex=sc.nextInt(); out.println("请输入狗狗的亲密度（1~100之间）："); Dog dog = new Dog(name, sex, sc.nextInt()); dog.show(); }else {//企鹅 out.println("请选择企鹅的性别：(1.Q仔 2.Q妹)"); int sex=sc.nextInt(); out.println("请输入企鹅的健康值（1~100之间）："); Penguin p = new Penguin(name, sex, sc.nextInt()); p.show(); } }}
总结
