Java类（1对多）

class Province {
    private int pid;
    private String name;
    private City citys [] ;
    public void setCitys(City citys[]){
      this.citys=citys;
      }
    public City [] getCity(){
      return this.citys;
      }
    public Province (int pid,String name){
      this.pid=pid;
      this.name=name;
      }
    public String getInfo(){
     return "省份ID："+pid+" , 名称："+name;
     }
}
class City{
    private int cid;
    private String cname;
    private Province province;
    public void setProvince(Province province){
       this.province=province;
       }
    public Province getProvince(){
       return this.province;
       }
    public City(int cid,String cname){
    this.cid=cid;
    this.cname=cname;
    }
    public String getInfo(){
    return "城市ID："+cid+",城市名称："+cname;
    }
}

public class dare
{public static void main(String args[]){
   City aa = new City(1,"江西");
   City bb = new City(2,"湖南");
   Province pr = new Province(0,"中国");
   aa.setProvince(pr);
   bb.setProvince(pr);
   pr.setCitys(new City[] {aa,bb});
   System.out.println("*****************开始取出省份信息****************");
   System.out.println(aa.getProvince().getInfo());
   System.out.println("*****************开始取出城市信息****************");
   System.out.println(pr.getInfo());
   for (int x = 0;x<pr.getCity().length ;x++ )
   {System.out.println("	|-"+pr.getCity()[x].getInfo() );
   }
  System.out.println("*****************已经全部取出****************");
   }
}

class Province {
    private int pid;
    private String name;
    private City citys [] ;
    public void setCitys(City citys[]){
      this.citys=citys;
      }
    public City [] getCity(){
      return this.citys;
      }
    public Province (int pid,String name){
      this.pid=pid;
      this.name=name;
      }
    public String getInfo(){
     return "省份ID："+pid+" , 名称："+name;
     }
}
class City{
    private int cid;
    private String cname;
    private Province province;
    public void setProvince(Province province){
       this.province=province;
       }
    public Province getProvince(){
       return this.province;
       }
    public City(int cid,String cname){
    this.cid=cid;
    this.cname=cname;
    }
    public String getInfo(){
    return "城市ID："+cid+",城市名称："+cname;
    }
}

public class dare
{public static void main(String args[]){
   City aa = new City(1,"江西");
   City bb = new City(2,"湖南");
   Province pr = new Province(0,"中国");
   aa.setProvince(pr);
   bb.setProvince(pr);
   pr.setCitys(new City[] {aa,bb});
   System.out.println("*****************开始取出省份信息****************");
   System.out.println(aa.getProvince().getInfo());
   System.out.println("*****************开始取出城市信息****************");
   System.out.println(pr.getInfo());
   for (int x = 0;x<pr.getCity().length ;x++ )
   {System.out.println("	|-"+pr.getCity()[x].getInfo() );
   }
  System.out.println("*****************已经全部取出****************");
   }
}