java - Store two enum values in a HashMap -

i want store socket.getsocket() , socketstatus.getsocketstatus() in hashmap. hmap.put(socket.getsocket(),socketstatus.getsocketstatus()); throws nullpointerexception. how resolve this?

below 2 classes:

socketinfomap.java

package vd.socket.map;  import java.util.hashmap; import java.util.map;  public class socketinfomap {      public enum socket {          one("01"), two("02"), three("03"), four("04"), five("05"), six("06"), seven("07"), eight("08");          private static map<socket, string> smap = new hashmap<socket, string>();         private string socket;          private socket(string socket) {             this.socket = socket;         }          public string getsocket() {             return socket;         }          static {             (socket socket : socket.values()) {                 smap.put(socket, socket.getsocket());             }          }     }      public enum socketstatus {          lifted(1), not_lifted(0);          private static map<socketstatus, integer> stmap = new hashmap<socketstatus, integer>();         private int socketstatus;          private socketstatus(int socketstatus) {             this.socketstatus = socketstatus;         }          public int getsocketstatus() {             return socketstatus;         }          static {             (socketstatus socketstatus : socketstatus.values()) {                 stmap.put(socketstatus, socketstatus.getsocketstatus());             }          }     }      private static map<string, integer> hmap = new hashmap<string, integer>();      public socketinfomap(map<string, integer> hmap) {         socketinfomap.hmap = hmap;     }      public map<string, integer> gethmap() {         return hmap;     }  } 

socketmaptest.java

package vd.socket.map;  import java.util.map; import vd.socket.map.socketinfomap.*;  public class socketmaptest {     private static map<string, integer> hmap;      public static void main(string[] args) {          socketstatus socketstatus = socketstatus.lifted;         socket socket = socket.two;          if ((socket == socket.two) && (socketstatus == socketstatus.lifted)) {             hmap.put(socket.getsocket(), socketstatus.getsocketstatus());             system.out.println(hmap);         } else             hmap.put(socket.getsocket(), socketstatus.getsocketstatus());         system.out.println(hmap);      } } 

initialize hmap inside main method.. go through link ,hopefully you..

how store enum types map?