Map的遍历获取key和vlue的两种方法
方式一:
@Test
public void forMap(){
Map<String, String> map = new HashMap<String, String>();
map.put(null, null);
map.put("xxx", null);
map.put("aaa", "111");
map.put("bbb", "222");
map.put("ccc", "333");
Iterator<Entry<String, String>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Entry<String, String> entry = iterator.next();
System.out.println(entry.getValue()+":"+entry.getValue());
}
}
方式二:
方式二比较适合用于数据大使用
@Test
public void t1(){
Map<String, String> map = new HashMap<String, String>();
map.put(null, null);
map.put("xxx", null);
map.put("aaa", "111");
map.put("bbb", "222");
map.put("ccc", "333");
System.out.println(map);
//mapd的遍历
for(Entry<String, String> entry:map.entrySet()){
System.out.println(entry.getKey()+":"+entry.getValue());
}
}*/