[icedtea-web] RFC: parse jnlps containing component-desc as well as application-desc elements

[Omair Majid]

On 10/29/2010 11:20 AM, Deepak Bhole wrote:
> * Omair Majid<omajid at redhat.com>  [2010-10-28 17:09]:
>> On 10/27/2010 03:14 PM, Omair Majid wrote:
>>> Hi,
>>>
>>> Some JNLPs such as space weasel [1] contain a "component-desc" element
>>> along with an "application-desc" element. Netx current fails trying to
>>> run such an application. The parser error says that having multiple
>>> *-desc elements is not supported. In the case of "component-desc" this
>>> does not make much sense. "application-desc", "applet-desc" and
>>> "installer-desc" describe what should be done with this jnlp file;
>>> "component-desc" carries no such meaning, so it should be ok to have a
>>> "component-desc" along with "application-desc" in the same JNLP file.
>>> The attached patch fixes this.
>>>
>>
>> A very slightly updated patch attached. Instead of using recursion
>> (and always returning null - my mistake) in getComponent, return a
>> new ComponentDesc. As far as I know nothing in netx actually uses
>> ComponentDesc - applications that loaded components/extensions
>> worked before this patch, work with the patch I posted yesterday and
>> work with this latest patch.
>>
>>> ChangeLog:
>>> 2010-10-27 Omair Majid<omajid at redhat.com>
>>>
>>> * netx/net/sourceforge/jnlp/JNLPFile.java: Add component.
>>> (getLaunchInfo): Modify javadoc to indicate that it does not return
>>> the ComponentDesc.
>>> (getComponent): Return component instead of launchType.
>>> (isComponent): Check if component is not null.
>>> (parse): Find and set component.
>>> * netx/net/sourceforge/jnlp/Parser.java
>>> (getLauncher): Remove all checks for component-desc. Allow having
>>> none of application-desc, applet-desc and installer-desc.
>>> (getComponent): Check for more than one component-desc element.
>>> Read and parse the component-desc.
>>>
>>> Any thoughts or comments?
>>
>> Anyone?
>>
>>> [1] http://spaceweasel.googlecode.com/svn/wiki/weasel.jnlp
>>>
>>
>> Thanks,
>> Omair
>
>> diff -r 5566a5487109 netx/net/sourceforge/jnlp/JNLPFile.java
>> --- a/netx/net/sourceforge/jnlp/JNLPFile.java	Wed Oct 27 15:55:55 2010 -0700
>> +++ b/netx/net/sourceforge/jnlp/JNLPFile.java	Thu Oct 28 16:49:24 2010 -0400
>> @@ -95,6 +95,9 @@
>>       /** the application description */
>>       protected Object launchType;
>>
>> +    /** the component description */
>> +    protected ComponentDesc component;
>> +
>>       /** the security descriptor */
>>       protected SecurityDesc security;
>>
>> @@ -402,7 +405,7 @@
>>
>>       /**
>>        * Returns an object of one of the following types: AppletDesc,
>> -     * ApplicationDesc, InstallerDesc, and ComponentDesc.
>> +     * ApplicationDesc and InstallerDesc
>>        */
>>       public Object getLaunchInfo() {
>>           return launchType;
>> @@ -441,7 +444,7 @@
>>           if (!isComponent())
>>               throw new UnsupportedOperationException(R("JNotComponent"));
>>
>> -        return (ComponentDesc) launchType;
>> +        return component;
>>       }
>>
>>       /**
>> @@ -474,7 +477,7 @@
>>        * Returns whether the lauch descriptor describes a Component.
>>        */
>>       public boolean isComponent() {
>> -        return launchType instanceof ComponentDesc;
>> +        return component != null;
>>       }
>>
>>       /**
>> @@ -574,6 +577,7 @@
>>               update = parser.getUpdate(root);
>>               resources = parser.getResources(root, false); // false == not a j2se/java resources section
>>               launchType = parser.getLauncher(root);
>> +            component = parser.getComponent(root);
>>               security = parser.getSecurity(root);
>>           }
>>           catch (ParseException ex) {
>> diff -r 5566a5487109 netx/net/sourceforge/jnlp/Parser.java
>> --- a/netx/net/sourceforge/jnlp/Parser.java	Wed Oct 27 15:55:55 2010 -0700
>> +++ b/netx/net/sourceforge/jnlp/Parser.java	Thu Oct 28 16:49:24 2010 -0400
>> @@ -598,16 +598,15 @@
>>
>>       /**
>>        * Returns the launch descriptor element, either AppletDesc,
>> -     * ApplicationDesc, ComponentDesc, or InstallerDesc.
>> +     * ApplicationDesc, or InstallerDesc.
>>        *
>>        * @param parent the parent node
>>        * @throws ParseException if the JNLP file is invalid
>>        */
>>       public Object getLauncher(Node parent) throws ParseException {
>>           // check for other than one application type
>> -        if (1 != getChildNodes(parent, "applet-desc").length
>> +        if (1<  getChildNodes(parent, "applet-desc").length
>>               + getChildNodes(parent, "application-desc").length
>> -            + getChildNodes(parent, "component-desc").length
>>               + getChildNodes(parent, "installer-desc").length)
>>               throw new ParseException(R("PTwoDescriptors"));
>
>
> Does the spec allow a jnlp without any of the above descriptors?
>

Yes. A JNLP extension can have just the <component-desc/> element. For 
example, take a look at the files at 
http://github.com/sgothel/jogl/tree/HEAD/jnlp-files. Of course, a file 
without any of the above elements can not be run directly; it must be 
used as an extension. If a user tries to run such a file directly, 
net.sourceforge.jnlp.Launcher will throw an exception.

Thanks,
Omair

>>
>> @@ -619,8 +618,6 @@
>>                   return getApplet(child);
>>               if ("application-desc".equals(name))
>>                   return getApplication(child);
>> -            if ("component-desc".equals(name))
>> -                return getComponent(child);
>>               if ("installer-desc".equals(name))
>>                   return getInstaller(child);
>>
>> @@ -693,8 +690,23 @@
>>       /**
>>        * Returns the component descriptor.
>>        */
>> -    public ComponentDesc getComponent(Node node) {
>> -        return new ComponentDesc();
>> +    public ComponentDesc getComponent(Node parent) throws ParseException {
>> +
>> +        if (1<  getChildNodes(parent, "component-desc").length) {
>> +            throw new ParseException(R("PTwoDescriptors"));
>> +        }
>> +
>> +        Node child = parent.getFirstChild();
>> +        while (child != null) {
>> +            String name = child.getNodeName();
>> +
>> +            if ("component-desc".equals(name))
>> +                return new ComponentDesc();
>> +
>> +            child = child.getNextSibling();
>> +        }
>> +
>> +        return null;
>>       }
>>
>>       /**
>