Field修改属性值 Field获取属性值

 1. 修改datas的username属性值

XXXClass datas = xxx.new XXXClass();
// XXXClass datas = new XXXClass();
Class cls = datas.getClass();
String key = "username"; //属性名
String value = "123";//目的属性值
for (Field field : cls.getDeclaredFields()) {
        if (field.getName().equals(key)) {
                field = cls.getDeclaredField(key);
                field.setAccessible(true);
                field.set(datas, value);// 动态设置值
                break;
        }
}

 2. 获取datas的username属性值

XXXClass datas = xxx.new XXXClass();
// XXXClass datas = new XXXClass();
Class cls = datas.getClass();
String key = "username"; //属性名
String value = "";
for (Field field : cls.getDeclaredFields()) {
        if (field.getName().equals(key)) {
                field = cls.getDeclaredField(key);
                field.setAccessible(true);
                value = field.get(datas).toString();// 动态获取值
                break;
        }
}