map-file

import java.io.BufferedReader;import java.io.FileOutputStream;import java.io.FileReader;import java.io.IOException;import java.util.HashMap;import java.util.Map;import java.io.File;import java.util.*;public class teststudy { public static void main(String[] args)  {   String targer= "i am test java study, i am test java study";  String tmp[] = targer.split(" ");  Map<String, Integer> testMap= new HashMap<String, Integer>();  int i;  for(i =0 ;i<tmp.length;i++)  {   if(testMap.containsKey(tmp[i]))   {    int num=testMap.get(tmp[i]);    testMap.put(tmp[i], ++num);   }   else   {    testMap.put(tmp[i],1);   }  }    System.out.println(testMap);  System.out.println(testMap.keySet());  System.out.println(testMap.size());  System.out.println(testMap.getClass());      File f = new File(".");  File[] filelist = f.listFiles();  int i = 0;  for(i = 0; i< filelist.length; i++)  {   if(filelist[i].isDirectory())   {    System.out.println("dir"+filelist[i]);   }   if(filelist[i].isFile())   {    System.out.println("file"+filelist[i]);   }   else   {    System.out.println("1111111111111");    System.out.println(filelist[i]);   }  }    File creatfile = new File("a..txt");  if(creatfile.exists() && creatfile.isFile())  {   creatfile.delete();  }  creatfile.createNewFile();  if(creatfile.canRead())  {   BufferedReader bf = new BufferedReader(new FileReader(creatfile));   String str = bf.readLine();   System.out.println(str);  }    String str[][] ={{"i"},{"am"},{"student"}};  String strbak[][] = new String[3][];  System.arraycopy(str,0,strbak,0,3);  for(int i=0; i< str.length;i++)  {   for(int j=0; j<str[i].length;j++)   {    System.out.println(str[i][j]);   }  } }} class testThread extends Thread{  long min; public testThread(long min)  {  this.min = min; }  public void run() {  for(int i=0 ; i< min; i++)  {  if(min%2 ==0)  {   System.out.println("thread1 say:"+min);  }  else  {   min--;  }  }   }}