java map的遍历
Java代码:
<PRE class=java name="code">package TEST;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;
/**
* @author Administrator
*
*/
public class TraversalMap {
public static void main(String[] args) {
Map<Object, Object> map = buildMap();
// TraversalMap1(map);
// TraversalMap2(map);
TraversalMap3(map);
// TraversalMap4(map);
}
/**
* @return map
*/
public static Map<Object, Object> buildMap(){
Map<Object, Object> map = new HashMap<Object, Object>();
map.put("王力宏", "你不知道的事");
map.put("梁静茹", "可惜不是你 ");
map.put("凤凰传奇", "荷塘月色");
map.put("王菲", "红豆");
map.put("周杰伦", "半兽人");
map.put("邓丽君", "好久不见");
return map;
}
public static void TraversalMap1(Map<Object, Object> map){
Set<Object> set = map.keySet();
Iterator<Object> it = set.iterator();
while(it.hasNext()){
Object o_key = it.next();
System.out.println("map : <key : "+o_key+"--value : "+map.get(o_key)+">");
}
}
/**
* @param map
* 得到map的values
*/
public static void TraversalMap2(Map<Object, Object> map){
Collection<Object> c = map.values();
Iterator<Object> it = c.iterator();
while(it.hasNext()){
Object o_key = it.next();
System.out.println("map : <key : "+"****"+"--value : "+o_key+">");
}
}
/**使用Map.Entry得到这一个map，然后分离出key和values
* @param map
*/
public static void TraversalMap3(Map<Object, Object> map){
Set<Entry<Object,Object>> set = map.entrySet();
Iterator<Entry<Object, Object>> it = set.iterator();
while(it.hasNext()){
Entry<Object, Object> map_entry = it.next();
System.out.println("map : <key : "+map_entry.getKey()+"--value : "+map_entry.getValue()+">");
}
}
/**
* 简单点的
* @param map
*/
public static void TraversalMap4(Map<Object, Object> map){
for(Object o: map.values()){
System.out.println("map : <key : "+getKey(map, o)+"--value : "+o+">");
}
}
/**
* 根据value得到key
* @param Map
* @param Object
*/
public static Object getKey(Map<Object, Object> map,Object value){
Set<Object> set = map.keySet();
Iterator<Object> it = set.iterator();
while(it.hasNext()){
Object temp_o = it.next();
if(map.get(temp_o).equals(value)){
return temp_o;
}
}
return null;
}
}
</PRE>
