/*
 *  Copyright © 1999, Oracle Corporation. All rights reserved.
 */


package oracle.jsp.sample.event;

import java.lang.reflect.*;
import oracle.jsp.event.*;

public class PageEventDispatcher extends Object implements JspScopeListener {

    private Object page;
    private String methodName;
    private Method method;

    public PageEventDispatcher() {
    }

    public Object getPage() {
        return page;
    }

    public void setPage(Object page) {
        this.page = page;
    }

    public String getMethodName() {
        return methodName;
    }

    public void setMethodName(String m) throws NoSuchMethodException, ClassNotFoundException  {
        method = verifyMethod(m);
        methodName = m;
    }

    public void outOfScope(JspScopeEvent ae) {
        int scope = ae.getScope();

        if ((scope == javax.servlet.jsp.PageContext.REQUEST_SCOPE  || scope == javax.servlet.jsp.PageContext.PAGE_SCOPE)
             && method != null) {
            try {
                Object args[] = {ae.getApplication(), ae.getContainer()};
                method.invoke(page, args);
            } catch (Exception e) {
                // catch all and continue
            }
        }
    }

    private Method verifyMethod(String m) throws NoSuchMethodException, ClassNotFoundException {
        if (page == null) throw new NoSuchMethodException("A page hasn't been set yet.");

        // Don't know whether this is a request or page handler so try one then the other
        Class c = page.getClass();
        Class pTypes[] = {Class.forName("javax.servlet.ServletContext"), Class.forName("javax.servlet.jsp.PageContext")};

        try {
            return c.getDeclaredMethod(m, pTypes);
        } catch (NoSuchMethodException nsme) {
            // fall through and try the request signature
        }

        pTypes[1] = Class.forName("javax.servlet.http.HttpServletRequest");
        return c.getDeclaredMethod(m, pTypes);
    }
}