Can't subclass a Java class that calls an abstract function in its constructor #2369
Description
From http://jira.codehaus.org/browse/JRUBY-2748
Original report
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