java从入门到精髓 - 集合类HashMap

import java.util.*;    //导入类
public class MapTest {

 /**
  * @param args
  */
 public static void main(String[] args){
  Map map = new HashMap();
  
  Emp emp = new Emp("001","张三");
  Emp emp2 = new Emp("005","张四");   //创建emp对象
  Emp emp3 = new Emp("004","王一");
  
  map.put(emp.getE_id(), emp.getE_name());
  map.put(emp2.getE_id(), emp2.getE_name());
  map.put(emp3.getE_id(), emp3.getE_name());
  
  Set set = map.keySet();
  Iterator it = set.iterator();
  System.out.println("HashMap类：无序");
  while(it.hasNext())    //遍历set
  {
   String str = (String)it.next();
   String name = (String)map.get(str);
   System.out.println(str + " "+ name);
  }
  TreeMap  treemap = new TreeMap();
  treemap.putAll(map);
  Iterator iter = treemap.keySet().iterator();
  System.out.println("treemap类map集合升序：");
  while(iter.hasNext())
  {
   String str = (String)iter.next();
   String name = (String)map.get(str);
   System.out.println(str+ " "+ name);
  }
  
 }

}

class Emp
{
 private String e_id;
 private String e_name;
 public Emp(String e_id,String e_name)
 {
  this.e_id = e_id;
  this.e_name =e_name;
 }
 /**
  * @return the e_id
  */
 protected String getE_id() {
  return e_id;
 }
 /**
  * @param e_id the e_id to set
  */
 protected void setE_id(String e_id) {
  this.e_id = e_id;
 }
 /**
  * @return the e_name
  */
 protected String getE_name() {
  return e_name;
 }
 /**
  * @param e_name the e_name to set
  */
 protected void setE_name(String e_name) {
  this.e_name = e_name;
 }
 
}