自己做的demo---宣告可以在java世界开始自由了

 package $interface;
 
 public interface ILeaveHome {
     public abstract int a();
     public abstract int b();
     public abstract int c();
     public abstract int d();
 
 }

 package $interface;
 
 public abstract class AbstractTools {
     private String abs01;//private的要设置访问器，外部的才可以访问
     private String abs02;
     public AbstractTools(String abs01,String abs02)
     {
         this.abs01=abs01;
         this.abs02=abs02;
     }
 
     public void tools1() {
         System.out.println("zzw abstract");
     }
     public abstract int tool2();
 
     public void setAbs01(String abs01)
     {
         this.abs01=abs01;
     }
     public String getAbs01()
     {
         return abs01;
     }
     public void setAbs02(String abs02)
     {
         this.abs02=abs02;
     }
     public String getAbs02()
     {
         return abs02;
     }
 }

 package $interface;
 
 public class LeaveHomeImpl extends AbstractTools implements ILeaveHome{
 
     public LeaveHomeImpl(String a,String b){
         super(a, b);//调用父类的构造方法
 
     }
     public int  tool2(){
         int a=6666;
         return a;
 
     }
     public int a(){
         int a=1;
         return a;
     }
     public int b(){
         int b=1;
         return b;
     }
     public int c(){
         int c=1;
         return c;
     }
     public int d(){
         int d=1;
         return d;
     }
 
     public static void main(String args[])
     {
         String z="z";
         String z6="z6";
         LeaveHomeImpl home=new LeaveHomeImpl(z,z6);
         System.out.println("home.a()="+home.a());
         System.out.println("home.b()="+home.b());
         System.out.println("home.c()="+home.c());
         System.out.println("home.d()="+home.d());
         System.out.println("home.tool2()="+home.tool2());
         System.out.println("getAbs01="+home.getAbs01());
         System.out.println("getAbs02="+home.getAbs02());
         home.tools1();
 
     }
 
 }

 package $interface;
 
 public class LeaveHomeTwice extends LeaveHomeImpl{
     String a;
     String b;
 
     public LeaveHomeTwice(){//第一种构造方式,
 
         super("a","b");//传值进去的时候会自动调用父类的有参数的构造方法
 
     }
     public LeaveHomeTwice(String a,String b){//带参数的构造方法，体现了构造方法的overload，构造方法的重载
 
         super(a,b);//改变了父类的值
 
     }
     //方法的override，方法的覆盖，对父类的覆盖
     public int  tool2(int a){
 
         int  zzw;
         zzw=a;
         return zzw;
 
     }
 
     public static void main(String args[])
     {
         int num=123;
         LeaveHomeTwice a=new LeaveHomeTwice();//对应第一种构造方式
         //LeaveHomeTwice a=new LeaveHomeTwice("zzwtwice","aiguotwice");//对应第二种构造方式
         System.out.println(a.a()+"\t"+a.b()+"\t"+a.c()+"\t"+a.d()+"\t"+a.tool2(num));
 
         a.tools1();
         System.out.println("getAbs01:"+a.getAbs01());
         System.out.println("getAbs02:"+a.getAbs02());
 
     }
 
 }