Get instant String object

Question

Is it possible to get the object that is specified in the code as a string at runtime?

Something like that:

public String xyz = "aaaa_bbb";

getObject("xyz").some function of String (e.g.: .split("_"))

thank

Answer 1

Here is an example

If this is a class field, you can get it by name like this.

import java.lang.reflect.Method;


public class Test {


    public String stringInstance = "first;second";

    public void Foo() {


        try {
            Object instance = getClass().getDeclaredField("stringInstance").get(this);
            Method m = instance.getClass().getMethod("split", String.class);

            Object returnValue = m.invoke(instance, ";");
            if(returnValue instanceof String[])
            {
                for(String s : (String[])returnValue )
                {
                    System.out.println(s);
                }
            }

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public static void main(String a[]){
        new Test().Foo();
    }



}

If this is a local variable of the method you are trying to connect to, then you may be able to jump to the variable from the current method from the call stack Thread.currentThread().getStackTrace().

Answer 2

You may need to rephrase the question.

If you just want to get the strings "aaaa" and "bbb" from the source string, you can use StringTokenizer

Answer 3

, , , . - :

    Class c = this.getClass();  // or Someclass.class
    Field f = c.getDeclaredField("xyz");
    String value = (String) f.get(this);
    ... = value.split("_");

( ...)

, , , Java ; Map.

Answer 4

, Field.

, , , , , . , :

• obejct, xyz
• ( Class#getDeclaredMethod(...))

.

, , , !

Answer 5

I have custom components on jPanel and I would like to work with them without redrawing them. I know if I use a list or map that this is possible, but I have to change the value on the map, and then redraw the GUI with the information on the map.