Java implementation of listening u disk sample sharing

package org.load.u;
import java.io.File;
import java.util.LinkedHashMap;
import java.util.Map;
//U disk test
public class CheckU {
 //Storage disk status
 private static Map<String, Boolean> map = new LinkedHashMap<String, Boolean>();
 //Define the disk
 private static final String[] arr = new String[] {"C", "D", "E", "F", "G", "H", "I", "J"};

 public static void main(String[] args){
  init();
  check();

  System.out.println(" detected U disc ");
  System.out.println(map);
 }

 //A dead loop detects each disk state
 public static void check() {
  File file ;
  for(;;) {
   for(String str : arr) {
    file = new File(str + ":\");

    //If the disk exists now and did not exist before
    //Just plugged in and returned
    if(file.exists() && !map.get(str)) {
     return;
    }

    //The saved state needs to be updated each time the state changes
    //If the state just detected is different from the original state, the state is reupdated
    //You must put it under the if statement above
    if(file.exists() != map.get(str)) {
     map.put(str, file.exists());
    }
   }

   try {
    Thread.sleep(5 * 1000);
   } catch (InterruptedException e) {
    e.printStackTrace();
   }
  }
 }

 //Initializes the disk state with true or false
 public static void init() {
  File file ;
  for(String str : arr) {
   file = new File(str + ":\");
   map.put(str, file.exists());
  }
 }
}