public class BeanWrapperTest {

    public static void main(String[] args) {
        User user=new User();

        BeanWrapper bw= PropertyAccessorFactory.forBeanPropertyAccess(user);
        bw.setPropertyValue("userName","张三");
        System.out.println(user);

        PropertyValue value=new PropertyValue("userName","李四");
        bw.setPropertyValue(value);
        System.out.println(user);

    }

}

public class User {

    String userName;

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    @Override
    public String toString() {
        return "User{" +
                "userName=‘" + userName + ‘\‘‘ +
                ‘}‘;
    }
}