Java简单类——一对多映射（省、市）

 class Province {
     private int pid ;
     private String name ;
     private City cities [] ;
     public Province (int pid,String name) {
         this.pid = pid ;
         this.name = name ;
     }
     public void setCities(City cities[] ){
         this.cities = cities ;
     }
     public City[] getCities() {
         return this.cities ;
     }
     public String getInfo() {
         return "省份编号：" + this.pid + "，名称：" + this.name ;
     }
 }
 class City {
     private int cid ;
     private String name ;
     private Province province ;
     public City (int cid,String name) {
         this.cid = cid ;
         this.name = name ;
     }
     public void setProvince(Province province){
         this.province = province ;
     }
     public Province getProvince() {
         return this.province ;
     }
     public String getInfo() {
         return "城市编号：" + this.cid + "，名称：" + this.name ;
     }
 }
 public class TestPC{
     public static void main(String args[]){
         Province pro = new Province (1,"湖北");
         City c1 = new City (1001,"武汉") ;
         City c2 = new City (1002,"孝感") ;
         City c3 = new City (1003,"宜昌") ;
         City c4 = new City (1004,"黄石") ;
         c1.setProvince(pro) ;
         c2.setProvince(pro) ;
         c3.setProvince(pro) ;
         c4.setProvince(pro) ;
         pro.setCities(new City [] {c1,c2,c3,c4}) ; //一个省份有多个城市
         System.out.println(c2.getProvince().getInfo()) ;
         for (int x = 0 ;x < pro.getCities().length ;x ++ ){
             System.out.println("\t|-" + pro.getCities()[x].getInfo()) ;
         }
     }
 }