Java takes its own defined object as the HashMap key

The Equals function and hashcode function that need to inherit map

Package Com.category;import Java.util.hashmap;public class Gencategoryleveldata {private static hashmap<category, integer> categorylevel = new hashmap<category, integer> (),/** * @param args */public static void main (string[] Ar GS) {//TODO auto-generated Method stub}/** * Category * @author Ouyangyewei * */public static class Category {public long Categ Oryid;public String CategoryName; @Overridepublic boolean equals (Object obj) {category category = (category) Obj;return ( this.categoryid==category.categoryid&& this.categoryName.equals (Category.categoryname));}            @Overridepublic final int hashcode () {int hashcode = 17;            Hashcode = hashcode * 31 + 1;            Hashcode = hashcode * 31 + 1;        return hashcode; }public category () {//Empty}public category (Long categoryId, String categoryname) {This.categoryid = CategoryId; This.categoryname = CategoryName;} Public long Getcategoryid () {return categoryId;} public void Setcategoryid (long categoryId) {This.categoryid = categoryId;} Public String Getcategoryname () {return categoryname;} public void Setcategoryname (String categoryname) {this.categoryname = CategoryName;}}}

Java takes its own defined object as the HashMap key