Question

I need to make a method that takes the name of a variable as its input, searches the class, and outputs the value pointed to by that variable. However, as you might have guessed, I am having problems with it:

public String myMethod(String varname) {
    return varname;
}

As you can see, all the above does is return the input string. Is there any way to get it to do otherwise?

Edit: for those requesting an explanation, here it is:

Suppose I have the following code:

String foo = "foo";
String bar = "bar";

I want to make a method that takes the name of a variable and returns its value. So, if I used the above method and wrote myMethod(foo), the output would be “foo”; similarly, I want myMethod(bar) to give “bar”.

Answer 1

Use the Java Reflection API. For example:

private String foo = "foo text";
private String bar = "some text";

public String myMethod(String varname) throws Exception {
  Class<?> c = this.getClass();
  Field field = c.getDeclaredField(varname);
  Object fieldValue = field.get(this);
  return fieldValue.toString();
}

// myMethod("foo") returns "foo text"
// myMethod("bar") returns "some text"

DEMO.

References:

• The Reflection API
• Getting and Setting Field Values