deployJava.runApplet() with cache

br...@databaseknowledge.com

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Apr 19, 2013, 10:15:39 AM4/19/13

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I have been experimenting with deployJava() / caching and I think I may have it working. I wanted to share this with the community and see if anyone may have any suggestions or comments:

Add this code exactly in the same place the where the <applet> tag would normal appear in the html:

var attributes = {codebase:"/jscripts/jprint/jZebra1.4.7/dist",

code:"jzebra.PrintApplet.class",

archive:"jzebra.jar",

name: "jzebra",

cache_option:"plugin",

cache_archive:"jzebra.jar",

cache_version:"0.1.4.7",

width:50,

height:50} ;

var parameters = {printer:"zebra"} ;

var version = "1.6" ;

deployJava.runApplet(attributes, parameters, version);

</script>

Watching the console is interesting. The first time this is run the console says things like:

network: Cache entry not found [url: https://mysite.com/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar, version: 0.1.4.7]

network: Connecting https://mysite.com/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar?version-id=0.1.4.7 with proxy=DIRECT

network: Connecting http://mysite.com:443/ with proxy=DIRECT

security: Loading Root CA certificates from C:\Program Files (x86)\Java\jre7\lib\security\cacerts

security: Loaded Root CA certificates from C:\Program Files (x86)\Java\jre7\lib\security\cacerts

security: Loading SSL Root CA certificates from C:\Program Files (x86)\Java\jre7\lib\security\cacerts

security: Loaded SSL Root CA certificates from C:\Program Files (x86)\Java\jre7\lib\security\cacerts

security: Loading certificates from Deployment session certificate store

security: Loaded certificates from Deployment session certificate store

network: Downloading resource: https://mysite.com/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar?version-id=0.1.4.7

Content-Length: 55,410

Content-Encoding: null

network: Wrote URL https://mysite.com/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar?version-id=0.1.4.7 to File C:\Users\myaccount\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\4\145f7b84-4704fa88-0.1.4.7--temp

So you can see the JVM is opening a connection to the web server and pulling down the jar file and then caching on the local file system.

The next time deployJava is run (even from a different browser page) the console says:

network: Cache entry found [url: https://mysite.com/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar, version: 0.1.4.7] prevalidated=false/0

cache: Adding MemoryCache entry: https://mysite.com/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar

network: Created version ID: 0.1.4.7

The JVM skips the network communication to download the jar files and uses the cached version. (nice!)

I think this is going in the right direction. A few things I would like to learn:

1. What does prevalidated=false/0 mean?

2. Is there a way to dynamically deployJava() so that the applet tag can be added to DOM only when needed?

Tres Finocchiaro

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Apr 19, 2013, 10:22:50 AM4/19/13

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Brian,

Thanks for your research on this. I have found very, very, very little on deployJava. I searched for a long time last night.

I did find dtjava, which is the updated version for JavaFX, but again, mixed reviews and very little help.

The issue I had with deployJava is that it was doing a document.write() and erasing the webpage every time it was called.

Were you able to work-around this issue?

I agree that it is a better method for caching the applet, but I know about as much about it as you.

-Tres

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br...@databaseknowledge.com

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Apr 19, 2013, 10:50:39 AM4/19/13

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I found something on stackoverflow where someone suggested redefining document.write before and and after deployJava call:

http://stackoverflow.com/questions/13517790/using-deployjava-runapplet-to-target-specific-element

I have not tired this approach. I'll keep messing around with things. I am not 100% certain how beneficial deployJava() really is, I think makes it easier to users to download the java and a few other things. Using Chrome, you can use "inspect element" and search for "applet" and see the applet tag setting in the DOM. So the end result of deployJava() is to push the <applet> into the dom.

It is probably possible to have a local copy of: https://java.com/js/deployJava.js" and change it write the applet to a div.

In the meantime, for people now wishing to use deployJava, It is also possible to caches the applet using html as:

<applet name="jzebra"

code="jzebra.PrintApplet.class"

archive="/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar"

>

</applet>

The JVM will use the cache version and bypass the network trip. This can be saved as javascript string and added into the DOM on demand.

br...@databaseknowledge.com

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Apr 19, 2013, 10:52:41 AM4/19/13

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typo correction:

In the meantime, for people not wishing to use deployJava, It is also possible to caches the applet using html as:

capp...@yahoo.com

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Apr 19, 2013, 11:03:31 AM4/19/13

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Hello Brian,

deployJava's function, as it name suggests, is to ensure user has correct version of java installed so that the deployment is properly made for the applet. When the user does not have the required version of java installed, it just redirects user to someplace he can download it (as far as I know this is configurable but never tried it)

Bahadir

From: "br...@databaseknowledge.com" <br...@databaseknowledge.com>
To: jzebra...@googlegroups.com
Sent: Friday, 19 April 2013, 17:50
Subject: Re: [jZebra] deployJava.runApplet() with cache

I found something on stackoverflow where someone suggested redefining document.write before and and after deployJava call:

http://stackoverflow.com/questions/13517790/using-deployjava-runapplet-to-target-specific-element

I have not tired this approach. I'll keep messing around with things. I am not 100% certain how beneficial deployJava() really is, I think makes it easier to users to download the java and a few other things. Using Chrome, you can use "inspect element" and search for "applet" and see the applet tag setting in the DOM. So the end result of deployJava() is to push the <applet> into the dom.

It is probably possible to have a local copy of: https://java.com/js/ deployJava.js" and change it write the applet to a div.

In the meantime, for people now wishing to use deployJava, It is also possible to caches the applet using html as:

<applet name="jzebra"

code="jzebra.PrintApplet.class"

archive="/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar"

>

</applet>

The JVM will use the cache version and bypass the network trip. This can be saved as javascript string and added into the DOM on demand.

br...@databaseknowledge.com

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Apr 19, 2013, 9:10:22 PM4/19/13

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As I am pressed for time, I decided to go with the <applet> tag instead of the javaDeploy:

<applet name="jzebra" code="jzebra.PrintApplet.class"

archive="/jscripts/jprint/jZebra1.4.7/dist/jzebra.jar"

style="width:110px; height: 110px; float: left;">

</applet>

Note that this is a bit different than the syntax I posted earlier. The param: "cache_archive" needs a relative path pointing to the jar file (exactly as the Archive attribute).

The console shows the jar file being reused bypassing 1 network round trip. Web server logs also confirm this.

That in itself makes the applet load faster than without cache. Just going off of feel, (sorry no time to benchmark) this is faster than not caching (no duh), and the deployJava() just a tad bit fastest.

So for now, I am going with this. When time permits I'll look at modifying https://java.com/js/deployJava.js so that the applet is appended into the dom before the </body> tag.

Tres Finocchiaro

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Apr 20, 2013, 9:48:48 AM4/20/13

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Thanks again for your time on this Brian.

I will put in a bug report to have the default option to cache this applet. It's fantastic advice and much appreciated research.

-Tres

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Jeroen Evers

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Apr 20, 2013, 10:47:48 AM4/20/13

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Regarding the document.write() from javaDeploy:

I used the docWriteWrapper() function from StackOverflow (mentioned before) in my project with jZebra and it works for me!

so give it a try: http://stackoverflow.com/questions/13517790/using-deployjava-runapplet-to-target-specific-element

I have added the extra cache params like this:

var parameters = {

cache_option: 'plugin',

cache_archive: APPLET_URL+','+APPLET_LIBS,

cache_version: '1.4.7'

};

seems to work just fine, I will test the performance boost on monday :)

-Jeroen-

Op zaterdag 20 april 2013 15:48:48 UTC+2 schreef Tres Finocchiaro het volgende:

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