Java基础：

枚举（enum）

    //枚举:定义4中加载状态    enum PagerState{        STATE_LOADING(1),        STATE_EMPTY(2),        STATE_ERROR(3),        STATE_SUCCESS(4);        private int value;        PagerState(int value){            this.value = value;        }        public int getValue(){            return value;        }    }

String 与 Byte[]的转换

String s = "abcdefg";//String转byte[]byte[] bytes = s.getBytes();//byte[]转StringString t = new String(bytes);

HashMap

StringBuffer sb2 = new StringBuffer();Iterator<Map.Entry<Integer, Boolean>> iterator = adapter.selectMap.entrySet().iterator();while (iterator.hasNext()) {    Map.Entry<Integer, Boolean> entry = iterator.next();    Integer key = entry.getKey();    Boolean value = entry.getValue();    if (!value) {        sb2.append(key + ",");    }}