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  1. JDK
  2. JDK-4671020

Exceptions not thrown while accessing non public or non existent methods/fields

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Details

    • Bug
    • Resolution: Won't Fix
    • P4
    • None
    • 1.4.1
    • deploy
    • generic
    • generic

    Description

      Browser: IE/NS6.x
      JRE: Hopper based (1.4.1)
      Platforms: Win32/Solaris/Linux


      According to definition, one is not allowed to access Private and Protected field values of a Java Object from Javascript.

      If one does try to then users should be warned to indicate the same.
      The only way is to throw JavaScript Exceptions.

      Currently if we try to access a private or protected field, it just goes
      through the call. No exceptions are thrown.

      Now the catch

      Say we have Java class "MyApplet" with a private variable 'intval' which is a integer

      From an HTML page if we assign
        document.MyApplet.intval=2

      and check value of 'document.MyApplet.intval', it displays 2.
      So we assume that it has set correctly in the Java Object.
      Right... No wrong.
      If we actually check the value of that private variable using a public method
       of that class, we would see that the value is not set to 2.

      Only if user uses the Method calls will they get the correct confirmation of whether it is set or not.


      Assume
       js_x is a javascript variable
       applet class name is "MyApplet" with private variable 'intval' whose value is 10
          and has a public class 'getInteger()' which 'returns intval'

      Assume operations as followes
       var js_x = 20
       document.MyApplet.intval = js_x

      On IE with MSVM
        value of document.MyApplet.intval is set to 20
        value of document.MyApplet.getInteger() is 10

      On IE with Java Plugin
        value of document.MyApplet.intval is set to 20
        value of document.MyApplet.getInteger() is 10

      On NS6 with Java Plugin
        value of document.MyApplet.intval is set to 20
        value of document.MyApplet.getInteger() is 10

        

      In all cases, no exceptions is thrown.
      The strange fact to note is that in Browser the value 20 for document.MyApplet.intval is cached.

      It has not allowed to set Private and protected fields, but has done so silently without any warning.



      Test case can be accessed from
      http://javaweb.sfbay.sun.com/~rpallath/plugin/oji/ojiprivate_field/Test_int_field.html

      (Also attached the Testcase)
      ###@###.### 2004-11-05 22:53:36 GMT

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              djayaramsunw Devananda Jayaraman (Inactive)
              rpallathsunw Rajendra Pallath (Inactive)
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