Java ArrayList contains details.

Apple.java

package com.jue.test;public class Apple {int id;String name;public Apple(int newid, String newname) {id = newid;name = newname;}@Overridepublic int hashCode() {final int prime = 31;int result = 1;result = prime * result + id;result = prime * result + ((name == null) ? 0 : name.hashCode());return result;}@Overridepublic boolean equals(Object obj) {if (this == obj)return true;if (obj == null)return false;if (getClass() != obj.getClass())return false;Apple other = (Apple) obj;if (id != other.id)return false;if (name == null) {if (other.name != null)return false;} else if (!name.equals(other.name))return false;return true;}}

MainTest.java

package com.jue.test;import java.util.ArrayList;import java.util.List;public class MainTest {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubList<Apple> lists = new ArrayList<Apple>();lists.add(new Apple(1, "a"));lists.add(new Apple(2, "b"));lists.add(new Apple(3, "c"));System.out.print(lists.contains(new Apple(1, "a")));}}

result:

true.