java - Recompile my code with -Xlint:unchecked.After recompiling with -Xlint , unchecked call warning appears . how do i run my program now? -

/** traversing elements */ import java.util.*;   class traversor extends thread { enumeration e; public traversor(enumeration e)  { this.e=e; } public void run() { system.out.println("new thread started, traversing vector  elements....."); while(e.hasmoreelements()) { system.out.println(e.nextelement()); try { thread.sleep(4000); } catch(exception ex) {} }  system.out.println("new thread completed"); } }   class vectortest{   public static void main(string args[]) { system.out.println("main thread started, creating vector..."); vector v=new vector(); v.addelement("one"); v.add("three");  v.add(1,"two");  enumeration e=v.elements(); system.out.println("vector created ,enumeration obtained"); traversor th=new traversor(e); th.start(); system.out.println(" new thread launched , suspending main thread");  try{ thread.sleep(1000);  } catch(exception ex) {} system.out.println("main thread resumed,modifying vector"); v.add("four"); v.add("five"); system.out.println("vector modified, main thread completed"); } } 

java introduced (rather late) typing of collection items vector of objects vector<t>, t type parameter given, vector<string>. (it called generic typing.)

now compiler can "check" whether item types alright.

class traversor<t> extends thread {      enumeration<t> e;      public traversor(enumeration<t> e) {         this.e = e;     }      public void run() {         system.out.println("new thread started, traversing vector  elements.....");         while (e.hasmoreelements()) {             system.out.println(e.nextelement());             try {                 thread.sleep(4000);             } catch (exception ex) {             }         }          system.out.println("new thread completed");     } }  class vectortest {      public static void main(string args[]) {         system.out.println("main thread started, creating vector...");         vector<string> v = new vector<>();         v.addelement("one");         v.add("three");         v.add(1, "two");          enumeration<string> e = v.elements();         system.out.println("vector created ,enumeration obtained");         traversor<string> th = new traversor<>(e);         th.start();         system.out.println(" new thread launched , suspending main thread");          try {             thread.sleep(1000);         } catch (exception ex) {         }         system.out.println("main thread resumed,modifying vector");         v.add("four");         v.add("five");         system.out.println("vector modified, main thread completed");     } } 

by way vector , enumeration rather old. 1 seldom sees vector nowadays.

// alternative vector: list<string> list = new arraylist<>(); list.add("alpha"); (string s : list) { ... }  // alternative enumeration: iterator<string> iterator = list.iterator(); while (iterator.hasnext()) {      string s = iterator.next(); }