Inner class data access

[Tom Johnson]

Below is code with a method-local inner class. The outer class, the method in which the inner class is defined and the inner class itself have a final attribute called string. How can you access the string defined in the method in this case?

public class InnerTest {
  final String string = "private outer string";
 
  public void testInner(){
    final String string = "Method defined string";
 
    // Define method-local inner class
    class MethodLocalInnerClass{
      private final String string = "Private attribute of inner class";
 
      public void InnerTestStrings() {
      System.out.println("default string : " + string);
      System.out.println("this.string : " + this.string);
      System.out.println("InnerTest.this.string : "+ InnerTest.this.string);
      }
    }  // End method-local inner class
 
    // Instantiate the inner class and call the method InnerTestStrings
    MethodLocalInnerClass inner = new MethodLocalInnerClass();
    inner.InnerTestStrings();
  }
 
  public static void main(String [] args) {
    InnerTest innerTest = new InnerTest();
    innerTest.testInner();
  }
}

This prints
default string : Private attribute of inner class
this.string : Private attribute of inner class
InnerTest.this.string : private outer string

as expected. So how do u explicity reference the other string to print
"Method defined string"? It is possible at all??

//Tom



(

tags added)
[ May 16, 2005: Message edited by: Barry Gaunt ]

[Barry Gaunt]

I do not think you can. The variable string in the testInner method is hidden by that class variable string defined in the method local class.

I suspect that there may be some tricky stuff possible using reflection but that's beyond the scope of SCJP.
[ May 16, 2005: Message edited by: Barry Gaunt ]

[Barry Gaunt]

public class InnerTest {
  final String string = "private outer string";
 
  public void testInner(){
    final String string = "Method defined string";
 
    // Define method-local inner class
    class MethodLocalInnerClass{
      String methodString;
      MethodLocalInnerClass(String s) {
          methodString = s;
      }
      private final String string = "Private attribute of inner class";
 
      public void InnerTestStrings() {
      System.out.println("default string : " + string);
      System.out.println("this.string : " + methodString);
      System.out.println("InnerTest.this.string : "+ InnerTest.this.string);
      }
    }  // End method-local inner class
 
    // Instantiate the inner class and call the method InnerTestStrings
    MethodLocalInnerClass inner = new MethodLocalInnerClass(string);
    inner.InnerTestStrings();
  }
 
  public static void main(String [] args) {
    InnerTest innerTest = new InnerTest();
    innerTest.testInner();
  }
}

In the above, I have added a constructor which smuggles the method's string into the state of the inner class. Then you can access it from within the method InnerTestStrings. Mucky though.

[Tom Johnson]

Yep that indeed will work since the method local variable shadows the outer class variable....but as you say its awkward. Dont really think the above situation arises very often anyways as it is bad naming convention, but wondering was there a way to do it