Question

I am running a Java application through my JSP page.
is it possible to redirect everything that the Java app prints into System.out into my page?

Edit:
I have a package pkg which contains a main function. this function has lots of System.out.println calls. e.g.

package pkg;
public class pkg {
    public static void main(String[] args) {
        System.out.println("Hello");
    }
}

In my index.jsp I call:

<%
    pkg.pkg.main(new String[] {});
%>

I need to see everything the pkg.pkg.main prints on the page. e.g.

Hello

Answer 1

Refactor the code of the called class so that it takes a Writer as argument, and print to this Writer rather than System.out:

package pkg;
public class pkg {
    public static void main(String[] args) {
        main(new OutputStreamWriter(System.out), args);
    }

    public static void main(Writer writer, String[] args) {
        PrintWriter out = new PrintWriter(writer);
        out.println("Hello");
    }
}

and call this second main method from your JSP (which should be a servlet):

<%
    pkg.main(out, new String[] {});
%>