Univerzal类设置器-Java

Question

Since I have a class with 8 parameters (p1,p2,...), all of type boolean, I was wondering if it is possible to create a setter method that has two parameters : object's variable member (to determine which of p1,p2,... to set) and a value , instead of creating 8 different setters).

Let's say we have following class:

public class SomeClass{

    private boolean p1;
    private boolean p2;
    private boolean p3;
    private boolean p4;
    private boolean p5;
    private boolean p6;
    private boolean p7;
    private boolean p8;
}

How is it possible to create an univerzal setter for any of those p1-p8 ? Something like:

public void setP(SomeClass.param p, boolean value)

Answer 1

You can use BeanUtils from apache commons

void setP(String name, Boolean value) {
    BeanUtils.setProperty(this, name, value);
}

or using an int

void setP(Integer i, Boolean value) {
    BeanUtils.setProperty(this, "p"+i.toString(), value);
}

generally speaking it works, but be aware it is not totally safe, since both name or i can assume illegal values and you should better add a some sanity check, otherwise you can get an IllegalAccessException or an InvocationTargetException . The advantage of using the 8 setter is of course compile time checking, and your ide can write them for you. And of course, as suggested, this library is using reflection.