java Map 怎么遍历

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

public class Du {

public static void main(String[] args) {

Map map = new HashMap();
visitMapByKey(map);//通过key遍历
visitMapByEntry(map);//通过entry遍历
}

private static void visitMapByEntry(Map map) {
Iterator ite = map.entrySet().iterator();

while(ite.hasNext()){
Map.Entry<Object, Object> entry = (Entry<Object, Object>) ite.next();
Object key = entry.getKey();//map中的key
Object value = entry.getValue();//上面key对应的value
}
}

private static void visitMapByKey(Map map) {
Iterator keys = map.keySet().iterator();

while(keys.hasNext()){
Object key = keys.next();//key
Object value = map.get(key);//上面key对应的value
}
}
}