HashMap遍历

方式1
Iterator iterator = hm.keySet().iterator();
while(iterator.hasNext()) {
System.out.println(hm.get(iterator.next()));
}
方式2
Set set = hm.entrySet() ;
java.util.Iterator it = hm.entrySet().iterator();
while(it.hasNext()){
java.util.Map.Entry entry = (java.util.Map.Entry)it.next();
// entry.getKey() 返回与此项对应的键
// entry.getValue() 返回与此项对应的值
System.out.println(entry.getValue());
}