- HashMap.entrySet()
for (Map.Entry<Integer, Integer> entry : hashmap.entrySet(){
System.out.print("(" + entry.getKey() + "," + entry.getValue() + ") ");
}
System.out.println("are in the hash map.");
// (0,9) (99,2) are in the hash map.
for (Map.Entry<Integer, Integer> entry : hashmap.entrySet(){
System.out.print("(" + entry.getKey() + "," + entry.getValue() + ") ");
}
System.out.println("are in the hash map.");
// (0,9) (99,2) are in the hash map.
ThreadLocal的使用,,,實際上相當於維護了一個Map,其中以鍵值對的形式,存儲了某一個數據被多個線程訪問所對應的值。當然這個數據只能有
JSONArray序列化日期最初用到, 這個是全局設置,會有風險。 String[] dateFormats = new String[] {"yyyyMMdd"}; JSONUtils.getM