B4J Question Accessing a 'protected' member of a class in Java

[jkhazraji]

How to access a member of a class in Java with a modifier 'protected' using Javacode or inline java in B4J so that a new instance can be initialized from it.
e.g.,

dim Obj as JavaObject = (Me).As(JavaObject).InitializeNewInstance("classA.classB.protectedClassMember",Null);

I searched in the forum and found the jReflection library of Mr. Graham @agraham but I could not figure out the way it accesses the Java objects
not exposed to the B4J language.

The working answer will be greatly appreciated.

 

[jkhazraji]

I tried using jRelection library as the following line:

Private rfRoot As Reflector
Private root As JavaObject
'
'
'
'
root=rfRoot.CreateObject("classA.classB.protectedClassmember")

However, it gave the error:
java.lang.RuntimeException: java.lang.IllegalAccessException: class anywheresoftware.b4j.agraham.reflection.Reflection cannot access a member of class classA.ClassB.protectedmemberClass (in module .......) with modifiers "protected"

 

[Daestrum]

Easiest way is to extend the class in a public class.
Example:

Sub AppStart (Args() As String)
    ' works as expected
    Dim jo As JavaObject
    jo.InitializeNewInstance("b4j.example.main$NormalClass",Null) 
    Log(jo)
    Log(jo.RunMethod("getName",Null))
    
    ' works because sneaky extends MyProtectedClass
    Dim jo1 As JavaObject
    jo1.InitializeNewInstance("b4j.example.main$Sneaky",Null)
    Log(jo1)
    Log(jo1.RunMethod("getName",Null))

    ' doesn't work as class is protected
    Dim jo2 As JavaObject
    Try
        jo2.InitializeNewInstance("b4j.example.main$MyProtectedClass",Null)
        Log(jo2)
        Log(jo2.RunMethod("getName",Null))
    Catch 
        Log(LastException)
    End Try            
End Sub

#if java
protected static class MyProtectedClass{
    
    protected String name = "fred";
    
    protected String getName(){
        return name;
    }
}
public static class Sneaky extends MyProtectedClass{

    // name is not defined as it exists in MyProtectedClass
    public String getName(){
        return name;
    }
}

public static class NormalClass{

    String name = "Jimmy";
    
    public String getName(){
        return name;
    }
}
    
#End If

 

[drgottjr]

i read his post as meaning he's trying to get "fred"

 

[jkhazraji]

i read his post as meaning he's trying to get "fred"

Just trying to make ends meet..

 

[jkhazraji]

The following code also exposes any protected Java class without the need to use 'extends':

    Dim Class1 As JavaObject
    Dim unprotected as JavaObject
    Class1.InitializeStatic("java.lang.Class")
    unprotected= Class1.RunMethod("forName",Array("classA.classB.protectedClassmember"))