Launch Java Web Start Application from HTTPS urls

Question

My web application is developed in PHP that launch a java web start application. My jar is signed by the trusted certificate authority. It was working fine with No SSL web application. But now site has been configured with trusted SSL certificate.So now I am not able to launch my plugin.

I am getting this exception while launching the application.

Exception thrown :

java.lang.NullPointerException
 at com.sun.javaws.Main.launchApp(Unknown Source)
 at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
 at com.sun.javaws.Main.access$000(Unknown Source)
 at com.sun.javaws.Main$1.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)

My JNLP file is as below :

JNLP File :

<jnlp spec="1.0+" codebase="https://<<server_domain>>/MyPlugin/">
  <information>
    <title>Test Plugin</title>
    <vendor>Test</vendor>
    <description>Test Plugin</description>
    <description kind="short">Test Plugin</description>
    <offline-allowed/>
  </information>
  <security>
    <all-permissions/>
  </security>
  <update check="timeout" policy="always"/>
  <resources>
    <java version="1.7+"/>
    <jar href="MyPluginJar.jar" download="eager" main="false"/>
  </resources>
  <application-desc>
    <argument>test</argument>
    <argument>test</argument>
  </application-desc>
</jnlp>

Few Questions :

1. Is it possible to launch java web start from HTTPS site ?

2. I have gone through the demos provided by the Oracle ("tutorial site"). Tutorial site is HTTPS site but the codebase in JNLP file contains HTTP urls. Does it matter of concern ?

3. Is there anything wrong in my JNLP ?

4. Is there a way to allow this particular request in SSL configuration to serve ? (Server using for PHP site : apache web server)

5. Any other work around for the achieving this ?

Please help on this.

UPDATE :

I got the solution.

Solution :

The 2nd question ( I have gone through the demos provided by the Oracle ("tutorial site"). Tutorial site is HTTPS site but the **codebase in JNLP file contains HTTP urls. Does it matter of concern ?) I have asked was the **Really matter of concern.

I have deployed another application in the server with no SSL configuration. And I call that in the code-base to launch the java plugin.

Still, I didn't get the cause. But yes this is perfect work around for the exception.