Map<String,String> map = new HashMap();

Emp emp1 = new Emp("231","张三");

Emp emp2 = new Emp("422","李四");

Emp emp3 = new Emp("83","王五");

Emp emp4 = new Emp("321","傻吧");

Emp emp5 = new Emp("543","无语");

map.put(emp1.get_id(), emp1.get_name());

map.put(emp2.get_id(), emp2.get_name());

map.put(emp3.get_id(), emp3.get_name());

map.put(emp4.get_id(), emp4.get_name());

map.put(emp5.get_id(), emp5.get_name());

Set<String> set = map.keySet();

Iterator it1 = set.iterator();

System.out.println("输出HashMap的集合，无序：");

while(it1.hasNext()){

String id1 = (String)it1.next();

String name1 = (String)map.get(id1);

System.out.println(id1+"  "+name1);

}