java 遍历map

Map<String,String> map=new HashMap<String,String>();
map.put("name", "kaka");

//1. 第一种用for循环
for(Map.Entry<String, String> entry:map.entrySet()){
System.out.println(entry.getKey()+":"+entry.getValue());
}

//2. 第二种用迭代Iterator
Set set = map.entrySet();
Iterator i = set.iterator();
while(i.hasNext()){
Map.Entry<String, String> entry1=(Map.Entry<String, String>)i.next();
System.out.println(entry1.getKey()+":"+entry1.getValue());
}
Set set = map.entrySet();

//3. 用keySet()迭代
Iterator it=map.keySet().iterator();
while(it.hasNext()){
String key;
String value;
key=it.next().toString();
value=map.get(key);
System.out.println(key+":"+value);
}

//4. 用entrySet()迭代
Iterator it=map.entrySet().iterator();
String key;
String value;
while(it.hasNext()){
Map.Entry entry = (Map.Entry)it.next();
key=entry.getKey().toString();
value=entry.getValue().toString();
System.out.println(key+":"+value);
}