Using class.forname().newInstance() and "com.sun.jdi.InvocationException occurred invoking method" e

[O. Ziggy]

I am using class.forname to create a new instance of class.The classname comes from a properties.

Lets say i have several classes in two packages.

    com.package.Parser1
    com.package.Parser2
    com.package.Parser3
    com.package.ParserLoader
    com.package.ParserInterface

    net.package.parser4
    net.package.parser5
    net.package.parser6
    net.package.GenericParser

On initialisation, the above classnames are put in a vector. The vector is then accessed and each class is initialised as shown below

	while (tokens.hasMoreTokens())

			parsers.addElement(

                Class.forName((String) tokens.nextToken()).newInstance());
		}catch(Exception e){
			e.printStackTrace();
		}

The code above is in the class ParserLoader which is in the same package as parsers 1,2,3.

Parsers 1, 2 and 3 all implement the ParserInterface.
Parsers 4,5 and 6 all extend the GenericParser abstract class.
The GenericParser abstract class implements the ParserInterface.
None of the parsers have a constructor so default constructors will be used.

When i run the above it generates an exception shown below

com.sun.jdi.InvocationException occurred invoking method

Any ideas why this is happening and could the structure of the packaging be a cause for this?


Another problem i am having is i cant see any stack trace. There is no stacktrace! I only see that error in eclipse when i debug the application and look at the content of the parsers vector. The vector should contain references to the parser objects. The parsers in com.package.* package are fine but it is not creating instances of any parser in the net.package.* package.

[Ernest Friedman-Hill]

Are you sure that the interfaces and abstract classes aren't included in the list? If you broke that long line into several, you could print out the name of each class before attempting to process it; that's tell you which one was failing.

[O. Ziggy]

These classes are not loaded

com.package.ParserLoader    (Controller class)
com.package.ParserInterface (Interface)
net.package.GenericParser   (Abstract class)

They are just in the same package as the parser classes. They are not loaded as they are not in the list of classes to be loaded in the properties file.

The classes that dont get loaded are those in the net.package.* package.