JAVA自定义注解详情

@Documented
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ObjectFlag {
    //默认值
    String value() default "默认值1";
}

public class ObjectTest {
    @ObjectFlag
    String name;
    @ObjectFlag
    Integer age;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }

public class ObjectRun {
  public static <T> T setValueField(T t) throws IllegalAccessException {
        Class<?> cls = t.getClass();
        Field[] fields = cls.getDeclaredFields();
        for (Field field : fields) {
            boolean hasConfigField = field.isAnnotationPresent(ObjectFlag.class);
            field.setAccessible(true);//设置可以访问私有变量
            //若属性上有注解，使用注解的值作为key去配置文件中查找
            if (hasConfigField) {
                //获取注解的默认值
                Object annoValue = field.getAnnotation(ObjectFlag.class).value();
                System.out.println("当前的属性名称为:" + field.getName());
                System.out.println("当前属性类型:" + field.getGenericType().toString());
                //获取到属性的数据类型
                String type = field.getGenericType().toString();
                if (type.endsWith("String")) {//如果是字符串类型
                    field.set(t, annoValue.toString());
                }
            } else {  //若属性上没有注解，则使用属性名作为key去配置文件中查找
                System.out.println("属性" + field.getGenericType().toString() + "没有该注解");
            }
        }
        return t;
    }
}