通过反射获取某个对象属性是否存在，并获取对象值

    @SneakyThrowspublic static void main(String[] args) {User user = new User("张三", 10);// 获取指定属性名的值String propertyName = "name2";Field[] fields = user.getClass().getDeclaredFields();// 输出属性名Boolean flag = false;for (Field field : fields) {if (field.getName().equals(propertyName)) {flag = true;field.setAccessible(true);Object value = field.get(user);System.out.println(value);}}if (!flag) {System.out.println(user.getClass().getSimpleName() + ":对象不存在属性：" + propertyName );}}static class User {private String name;private int age;public void setName(String name) {this.name = name;}public String getName() {return name;}public void setAge(Integer age) {this.age = age;}public Integer getAge() {return age;}public User(String name, int age) {this.name = name;this.age = age;}}