日期:2014-05-20  浏览次数:20624 次

HashMap中怎么取得所有的键值对啊?
HashMap中怎么取得所有的键值对啊

------解决方案--------------------
取所有的键:
HashMap hm = new HashMap();
hm.put( "A_thlsd,, ", "01 ");
hm.put( "b_adhd ", "02 ");
hm.put( "c_decteln ", "03 ");
hm.put( "d_apple ", "04 ");
hm.put( "e_blue ", "05 ");
hm.put( "ff_drag ", "06 ");
hm.put( "g_cellention ", "07 ");
Set set = hm.keySet();

Object[] obj=set.toArray();
Arrays.sort(obj);
for(int i=0;i <obj.length;i++){
System.out.println(obj[i]);
}


取所有的键值:

HashMap hm = new HashMap();
hm.put( "A_thlsd,, ", "01 ");
hm.put( "b_adhd ", "02 ");
hm.put( "c_decteln ", "03 ");
hm.put( "d_apple ", "04 ");
hm.put( "e_blue ", "05 ");
hm.put( "ff_drag ", "06 ");
hm.put( "g_cellention ", "07 ");
Set set = hm.entrySet();

Object[] obj=set.toArray();
//Arrays.sort(obj);
for(int i=0;i <obj.length;i++){
System.out.println(obj[i]);
}
这个方法不好
------解决方案--------------------
1.
Set set = map.keySet();
Iterator it = set.iterator();
if(it.hasNext()){
Object j = it.next();
System.out.println(j);
System.out.println(map.get(j)) ;
}
2.
Set set = map.entrySet();
Iterator it = set.iterator();
if(it.hasNext()){
Map.Entry me = (Map.Entry) it.next();
System.out.println(me.getKey());
System.out.println(me.getValue());
}
------解决方案--------------------
Set set = map.entrySet();
Iterator it = set.iterator();
if(it.hasNext()){
Map.Entry me = (Map.Entry) it.next();
System.out.println(me.getKey()+ "= "+me.getValue());