HasnMap运用非系统类作为key

HasnMap使用非系统类作为key

1 key类覆写equals hashCode 方法

package collectionTest;import java.util.HashMap;import java.util.Map;class Person{private String name ;private int age ;public Person(String name,int age){this.name = name ;this.age = age ;}public String toString(){return "姓名：" + this.name + "；年龄：" + this.age ;}@Overridepublic boolean equals(Object obj) {if (this == obj){return true;}if (!(obj instanceof Person)){return false;}Person that = (Person)obj;if (this.name.equals(that.name) && this.age == that.age){return true;}return false;}@Overridepublic int hashCode() {return this.name.hashCode() * this.age;}};public class MapKeyTest {public static void main(String[] args) {Map<Person,String> map = new HashMap<Person,String>() ;map.put(new Person("张三",30),"zhangsan");// 增加内容System.out.println(map.get(new Person("张三",30))) ;}}