Increment memory for applet launched through jnlp

Question

I'm developing a java application that needs to do some calculations and needs to be available online.

I develop in Java since 2005 but never had to put online anything, I always used RMI.

I studied how to create applets and successfully converted my desktop application into an applet (applied applet lifecycle, converted JFrame into JApplet, etc.)

What I noticed is that performance is really slowed down, so I tried alternative ways. I read about Java Web Start, and started thinking about it.

Found this article: http://docs.oracle.com/javase/tutorial/deployment/deploymentInDepth/runAppletFunction.html and following it I did the following things (writing all down for future readers reference):

made a jar of my application and signed it (obviously names are altered)

wrote the following JNLP:

<?xml version="1.0" encoding="UTF-8"?>
<jnlp href="appJNLP.jnlp">
    <information>
        <title>Software title</title>
        <vendor>Society name</vendor>
        <offline-allowed />
    </information>
    <resources>
        <j2se version ="1.6+" initial-heap-size="256m" max-heap-size="1024m"
       href="http://java.sun.com/products/autodl/j2se" />
        <jar href="app.jar" main="true" />
        <jar href="mysql-connector-java-5.1.20-bin.jar"/>
        <jar href="poi-3.8-20120326.jar"/>
        <jar href="forms-1.3.0.jar"/>
    </resources>
    <applet-desc name="Name" main-class="mainClass" width="1024" height="700"/>
</jnlp>

wrote the following HTML page:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"         "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
        <title>Titolo</title>
    </head>
    <body>
        <script src="http://www.java.com/js/deployJava.js"></script>
        <script> 
            var attributes = {code:'mainClass.class', 
                        archive:'app.jar,mysql-connector-java-5.1.20-bin.jar,poi-3.8-20120326.jar,forms-1.3.0.jar', 
                        width:1024, height:700} ;
            var parameters = {jnlp_href:'appJNLP.jnlp'} ; 
            var version = '1.6' ;
            deployJava.runApplet(attributes, parameters, version);  
         </script>
         <noscript>This page requires JavaScript.</noscript>
    </body>
</html>

put the following files structure in my Tomcat webapp folder:

webapps\app
    app.jar
    appJNLP.jnlp
    page.html
    mysql-connector-java-5.1.20-bin.jar
    poi-3.8-20120326.jar
    forms-1.3.0.jar

As you can see I chose the mixed deployment way (stated on the link posted before this approach enables applet to run on the old and next generation Java Plug-in software). I think I did everything fine. The applet loads in the web page but it's very slow... I added memory parameters in the jnlp section following this response: How can I start an Java applet with more memory? (initial-heap-size="256m" max-heap-size="1024m") but they seem to get ignored. I tried also putting false values, like initial-heap-size="5000m" on my 2gb RAM machine, but the applet still loads and still is slow. The console shows this after a rundown of the jnlp file, but the applet still runs:

Match: selecting maxHeap: 8388608000
Match: selecting InitHeap: 5242880000
Match: digesting vmargs: null
Match: digested vmargs: [JVMParameters: isSecure: true, args: ]
Match: JVM args after accumulation: [JVMParameters: isSecure: true, args: ]
Match: digest LaunchDesc: http://localhost:8090/TestServer/gestioneoneri.jnlp
Match: digest properties: []
Match: JVM args: [JVMParameters: isSecure: true, args: ]
Match: endTraversal ..
security:  --- parseCommandLine converted : -Xms5000m
into:
[-Xms5000m]
Match: JVM args final: -Xmx8000m -Xms5000m

Shouldn't it throw an exception??

Now my questions are:

how can I be certain that the code is getting executed in JNLP environment and not in the applet environment? I see no Java Web Start logo. Is it normal?
how can I increase initial and max memory size to more human values?
I need this software to be embedded in the web page. Since I don't know if what I'm using is an applet or a java web start application, how can I improve my users experience? I'm talking about extending JApplet or JFrame for example.. In the case I cannot increase memory how should I convert my applet into a jws app?

I'm open to suggestions. Thank you for your time!

Andrea

score 0 · Answer 1 · answered Oct 27 '12 at 02:03

Emm... quite many abstract questions

I shall try to answer a little

So...

how can I be certain that the code is getting executed in JNLP environment and not in the applet environment? I see no Java Web Start logo. Is it normal?

If you start it with JNLP and the start was successful you can be sure it was started by JAWS; I don't see JAWS logos too... but it is normal. I don't remember since what JRE upgrade it disappears but to see your applet has been running by JRE you can simply watch the temp internet files cache (to see its jnlp file)

how can I increase initial and max memory size to more human values?

As I can remember, there is jnlp param which makes this... it is something like

<j2se version="1.3" initial-heap-size="64m" max-heap-size="128m"/>

see jnlp syntax for more details...

I need this software to be embedded in the web page. Since I don't know if what I'm using is an applet or a java web start application, how can I improve my users experience? I'm talking about extending JApplet or JFrame for example.. In the case I cannot increase memory how should I convert my applet into a jws app

In the case of JAWS application, as I can remember, there a JAWS logo should be shown during app starts. So you can easily separate applet from application I guess... Using application or applet it is all depends of your project requirements...

Increment memory for applet launched through jnlp

1 Answers1