java contructor parameters

[jphipps]

When writing a java class to be called from Sage, what parameters are used in the invocation of the class that would be used for the constructor?

I would like for the class to load some data to cache to be used by later method calls...

Thanks,
Jeff

[GKusnick]

The syntax is new_package_Class(args), per p. 151 of the Studio manual.

[jphipps]

Thanks, that did it, plus I didn't have the contructor declared as public which caused it not to work...

One question on how the studio manual shows how to use it. When you create a new instance of the class, and call the method with has the newly created object as the first argument, do you need to setup a method in the class to call the method within the object that is passed... I know that sounds a bit confusing... For example in sudo code:

Sage Define new instance:
X = new_package_class();

Sage Method call:

package_class_method(X,args)

Java:

class class
{
method(args)
{
some code
return value
}

method(Object o,args)
{
return o.method(args)
}
}

I was originally testing without using the object passed into the java class and it seem to always use the last object created....

Sorry if this sounds convoluted...

Thanks,
Jeff

[stuckless]

Assuming the following sample java....

package test.sage;
public class Foo {
    public Foo() {
    }

    public String hello(String name) {
        return "Hello " + name;
    }
}

in your stv code, you'd have something like...
FooInstance=new_test_sage_Foo()
Text=test_sage_Foo_hello(FooInstance, "world")

So, you can use existing java objects as is... ie,
File=new_java_io_File("myfile.jpg")
Exists=java_io_File_exists(File)

Hope that makes sense.

[jphipps]

I thought that is what I was doing. I had a method that had no args, and when I called it like you have it in your example, I was getting a java exception. When I added an (Object o) as the argument and basically ignored o in the code, the call worked. I will test it when I get home with your sample snippet, maybe I had another issue at the same time and was chasing a red hearing...

Thanks,
Jeff

[jphipps]

Thanks for your help Greg/Sean... Turned out to be a problem with my public/static on the methods..

Some reason, Eclipse suggested I put the static in while doing some testing, and after some cutting and pasting, it ended up all over...

Once I got them all straight, it is working like a charm...

Thanks again,
Jeff