首页 > 代码库 > java 16 - 15 集合嵌套存储和遍历元素

java 16 - 15 集合嵌套存储和遍历元素

 

  集合的嵌套遍历
  需求:
    自然界有很多动物的种类,猫科,犬科,鸟类这些。
    那就是有很多的ArrayList<Animal>
    而现在,我想要把这些ArrayList<Animal>也用集合存储,怎么办呢?
  那就使用集合的嵌套使用:
    就是这个样子的:ArrayList< ArrayList<Animal> >

动物类:

 1 package cn_JDK5new; 2  3 public class Animal { 4          5         private String name; 6         private String color; 7         private int age; 8          9         10         11         public Animal() {12             super();13             // TODO Auto-generated constructor stub14         }15         16         17         18         public Animal(String name, String color, int age) {19             super();20             this.name = name;21             this.color = color;22             this.age = age;23         }24         25         26         public String getName() {27             return name;28         }29         public void setName(String name) {30             this.name = name;31         }32         public String getColor() {33             return color;34         }35         public void setColor(String color) {36             this.color = color;37         }38         public int getAge() {39             return age;40         }41         public void setAge(int age) {42             this.age = age;43         }44         45         46 }

 

 

 

 

测试类:

 1 package cn_JDK5new; 2  3 import java.util.ArrayList; 4  5 import zl_ObjectTest1.Animal; 6  7 public class BigAnimalTest { 8  9 public static void main(String[] args) {10 //创建集合111 ArrayList<Animal> list1 = new ArrayList<Animal>();12 13 //猫科14 Animal a1 = new Animal("短尾猫","白色",1);15 Animal a2 = new Animal("加菲猫","黄色",3);16 Animal a3 = new Animal("波斯猫","黑色",2);17 18 //添加进到集合119 list1.add(a1);20 list1.add(a2);21 list1.add(a3);22 23 //创建集合224 ArrayList<Animal> list2 = new ArrayList<Animal>();25 26 //犬科27 Animal a4 = new Animal("哈士奇","白色",1);28 Animal a5 = new Animal("萨摩耶","纯白",2);29 Animal a6 = new Animal("中华田园犬","黑色",2);30 Animal a7 = new Animal("腊肠犬","黄色",3);31 Animal a8 = new Animal("泰迪","纯白",2);32 33 //添加进集合234 list2.add(a4);35 list2.add(a5);36 list2.add(a6);37 list2.add(a7);38 list2.add(a8);39 40 41 //创建集合342 ArrayList<Animal> list3 = new ArrayList<Animal>();43 44 //鸟类45 Animal a9 = new Animal("鸽子","白色",1);46 Animal a10 = new Animal("老鹰","黑色",2);47 48 //添加进集合349 list3.add(a9);50 list3.add(a10);51 52 53 //创建总的集合54 ArrayList<ArrayList<Animal>> bigAnimal = new ArrayList<ArrayList<Animal>>();55 //把这些集合都放进总集合中56 bigAnimal.add(list1);57 bigAnimal.add(list2);58 bigAnimal.add(list3);59 60 //进行总集合的遍历61 for(ArrayList<Animal> aa : bigAnimal){62 63 for(Animal a : aa){64 65 System.out.println(a.getName()+"\t"+a.getColor()+"\t"+a.getAge());66 }67 }68 }69 }

 

java 16 - 15 集合嵌套存储和遍历元素