j2ee集合些的一些总结,带实例

来源：互联网发布：burberry围巾知乎编辑：程序博客网时间：2024/04/30 18:46

package fzh.org;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

public class JiHe {
public void test1() {
  ArrayList al = new ArrayList();
  for (int i = 1; i < 10; i++) {
   al.add("ArrayList Element:" + i);
  }
  Iterator itr = al.listIterator();
  while (itr.hasNext()) {
   Object obj = itr.next();
   System.out.println(obj);
  }
}

public void test2() {
  HashSet hs = new HashSet();
  System.out.println("HashSet");
  for (int i = 1; i < 10; i++) {
   hs.add("HashSet Element:" + i);
  }
  Iterator itr = hs.iterator();
  while (itr.hasNext()) {
   Object obj = itr.next();
   System.out.println(obj);
  }
}

public void test3() {
  TreeSet ts = new TreeSet();
  System.out.println("TreeSet");
  for (int i = 1; i < 10; i++) {
   ts.add("TreeSet Element:" + i);
  }
  Iterator itr = ts.iterator();
  while (itr.hasNext()) {
   Object obj = itr.next();
   System.out.println(obj);
  }
}

public void test4() {
  HashMap hm = new HashMap();
  for (int i = 0; i < 10; i++) {
   hm.put("item" + i, "value" + i);
  }
  Set set = hm.entrySet();
  Iterator itr = set.iterator();
  while (itr.hasNext()) {
   Map.Entry me = (Map.Entry) itr.next();
   System.out.println(me.getValue());
  }
}

/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub
  JiHe j = new JiHe();
  j.test4();
}

}