[jruby-dev] [jira] Created: (JRUBY-2748) Can't subclass a Java class that calls an abstract function in its constructor

[Michael Bohn (JIRA)]

Can't subclass a Java class that calls an abstract function in its constructor
------------------------------------------------------------------------------

                 Key: JRUBY-2748
                 URL: http://jira.codehaus.org/browse/JRUBY-2748
             Project: JRuby
          Issue Type: Bug
          Components: Java Integration
    Affects Versions: JRuby 1.1.2
            Reporter: Michael Bohn


I have found that while subclassing a Java class that  calls an abstract 
function in its constructor will cause the initialization of the subclass in 
JRuby to throw an ArgumentError with message "Constructor invocation failed: 
null." 

Here is my Java base class:
package com.allstontrading.logalyzer;
import java.util.List;

public abstract class AbstractTest {
     protected String obj;

     public AbstractTest() {
          this("dog");
          this.run();
     }
     public AbstractTest(String obj) {
          this.obj = obj;
     }
        
     protected abstract List<String> myAbstractFunc();
     public void run() {
          if (this.myAbstractFunc() != null)
               for (String string : this.myAbstractFunc())
                    System.out.println("Big " + this.obj + "s Eat: " + string);
          else
               System.out.println("OMG");
     }
}

Here is my example JRuby script:
include Java

import 'com.allstontrading.logalyzer.AbstractTest'
import 'java.util.ArrayList'

class RubyTest < com.allstontrading.logalyzer.AbstractTest
    def initialize()
        super("Pink Elephant")
    end

    def myAbstractFunc()
        list = ArrayList.new
        list << "Cancerous Rocks"
        list << "Candy Apples"
        list << "Moldy Bread"
        return list
    end
end

puts "This test does NOT call an abstract function in the constructor."
test = RubyTest.new
test.run

class AnotherRubyTest < com.allstontrading.logalyzer.AbstractTest
    def initialize()
        super
    end
    
    def myAbstractFunc()
        list = ArrayList.new
        list << "Cancerous Rocks"
        list << "Candy Apples"
        list << "Moldy Bread"
        return list
    end 
end     
        
puts ""
puts ""
puts "This test does call an abstract function in the constructor."
anotherTest = AnotherRubyTest.new



Here is the output:
This test does NOT call an abstract function in the constructor.
Big Pink Elephants Eat: Cancerous Rocks
Big Pink Elephants Eat: Candy Apples
Big Pink Elephants Eat: Moldy Bread

This test does call an abstract function in the constructor.
/home/mbohn/jruby-1.1.2/lib/ruby/site_ruby/1.8/builtin/javasupport/utilities/base.rb:26:in
 `new_instance2': Constructor invocation failed: null (ArgumentError)
        from 
/home/mbohn/jruby-1.1.2/lib/ruby/site_ruby/1.8/builtin/javasupport/utilities/base.rb:26:in
 `__jcreate!'
        from 
/home/mbohn/jruby-1.1.2/lib/ruby/site_ruby/1.8/builtin/javasupport/proxy/concrete.rb:23:in
 `initialize'
        from rubyTestAbstract.rb:26:in `initialize'
        from 
/home/mbohn/jruby-1.1.2/lib/ruby/site_ruby/1.8/builtin/javasupport/proxy/concrete.rb:6:in
 `new'
        from 
/home/mbohn/jruby-1.1.2/lib/ruby/site_ruby/1.8/builtin/javasupport/proxy/concrete.rb:6:in
 `new'
        from rubyTestAbstract.rb:41



-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: 
http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

---------------------------------------------------------------------
To unsubscribe from this list, please visit:

    http://xircles.codehaus.org/manage_email