**Update 11/30
This has been acknowledged as a JavaWS bug: http://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8170522
The Problem
We appear to have uncovered a bug with the Java WebStart implementation on OS X, namely that webstart applications fail to launch external app via Desktop.getDesktop().open(File file) API. This only occurs when the Java WebStart app was launched from its desktop shortcut. Has anyone seen this behavior and/or can suggest a workaround and/or additional avenues of testing?
The Detail
On OS X platform, when using an API to open an external application such as Desktop.getDesktop().open(File file) from within a signed Java Webstart application the external application load always results in a crash of that application when the JavaWS app is launched from its desktop shortcut. When the exact same webstart app is launched directly from the JNLP file or from the cache in the Java Control Panel the external application loads without issue. This problem does not occur on Windows.
It is easy to replicate:
- Create a simple project with one class (Demo class below). This class only tries to all Desktop.getDesktop().open on an RDP file
- Bundle into a jar and sign (self sign is ok) (ant script below)
- Create a simple jnlp file (sample below)
- Deploy jar and jnlp to a webserver accessed via https
- Add webserver's domain to Java's exception list so that self signed app will run
Test as follows on OS X client machine:
- install latest Microsoft Remote Desktop app (v8.0.35) - ensure RDP files are associated with this app
- ensure the RDP client is closed
- download/run the jnlp file from the webserver it was uploaded to above
- JavaWS app will open and successfully open RDP client and load the RDP file
- ensure RDP client and demo app are closed
- load the demo app from its desktop icon <=== this is the failure case
- RDP client will start to open and then crash
- ensure RDP client and demo app are closed
- load app from java cache <=== this should have the same behaviour as loading from a desktop icon
- app will open and successfully open RDP client and load the RDP file
The same behavior has been observed with any command the app can issue that will open another application, i.e. this is not just seen with RDP files/app... when the JavaWS app has been loaded from its desktop shortcut, every mechanism we've tried.
When loaded from JNLP directly or from the Java cache within the Java Control Panel the exact same code works without issue. There are no errors or warnings seen in the code so it appears the external command is issued successfully however the way the JVM is interacting with the OS must differ in the two scenarios.
Can anyone suggest what can be done to change the behavior of the webstart app when loaded from its desktop shortcut and make the Windows and OS X experiences consistent?
Files to replicate the issue are below:
Demo class with the open command:
package com.example;
import java.awt.*;
import java.io.File;
import java.util.logging.Logger;
public enum Demo {
INSTANCE;
private static final Logger log = Logger.getLogger(Demo.class.getName());
public static void main(String[] args) {
Demo demo = Demo.INSTANCE;
String filename = System.getProperty("user.home")
+ System.getProperty("file.separator")
+ "test.rdp";
log.info("opening file: " + filename);
demo.openFile(new File(filename));
}
public void openFile(File file) {
log.info("Desktop.getDesktop().open(" + file.getAbsolutePath() + ")");
try {
if (file.exists()) {
Desktop.getDesktop().open(file);
} else {
log.info("Cannot open file " + file.getAbsolutePath() + " does not exist.");
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
Demo JNLP file:
<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="6.0+"
codebase="https://yourwebserver.example.com/path/to/app"
href="OpenDemo.jnlp" >
<information>
<title>Open Demo</title>
<vendor>Example</vendor>
<shortcut online="true" install="true">
<desktop/>
</shortcut>
<update check="timeout" policy="always"/>
</information>
<security>
<all-permissions/>
</security>
<resources>
<java version="1.8+" />
<jar href="./OpenDemo.jar" main="true" />
</resources>
<application-desc
main-class="com.example.Demo" />
</jnlp>
ANT build file:
<?xml version="1.0" encoding="UTF-8"?>
<project name="Build Open Demo WebStart Application">
<property name="compiled.basedir" value="../out/production/demo-webstart-app/" />
<property name="target.jarname" value="OpenDemo.jar" />
<!-- default the target to be 1.8 -->
<property name="ant.build.javac.target" value="1.8" />
<property name="ant.build.javac.source" value="1.8" />
<!-- bundle the jar -->
<target name="bundle">
<jar destfile="../${target.jarname}"
filesetmanifest="mergewithoutmain"
basedir="${compiled.basedir}" >
<include name="com/example/**" />
<manifest>
<attribute name="Application-Name" value="OpenDemo" />
<attribute name="Codebase" value="*" />
<attribute name="Permissions" value="all-permissions" />
<attribute name="Caller-Allowable-Codebase" value="*" />
<attribute name="Entry-Point" value="com.example.Demo" />
<attribute name="Trusted-Only" value="true" />
</manifest>
</jar>
</target>
<!-- sign what we have bundled with a self signed CA -->
<!-- cert created using:
keytool -genkey -keyalg RSA -alias selfsigned -keystore keystore -storepass opendemo -validity 30 -keysize 2048
What is your first and last name?
[Unknown]: OpenDemo
What is the name of your organizational unit?
[Unknown]: OpenDemo
What is the name of your organization?
[Unknown]: OpenDemo
What is the name of your City or Locality?
[Unknown]: OpenDemo
What is the name of your State or Province?
[Unknown]: OpenDemo
What is the two-letter country code for this unit?
[Unknown]: OD
Is CN=OpenDemo, OU=OpenDemo, O=OpenDemo, L=OpenDemo, ST=OpenDemo, C=OD correct?
[no]: yes
Enter key password for <selfsigned>
(RETURN if same as keystore password):
-->
<target name="sign" depends="bundle">
<signjar
jar="../${target.jarname}"
lazy="false"
alias="selfsigned"
keystore="../keystore"
storepass="opendemo"
/>
</target>
</project>
