Can you capture end user's Java version when they run an applet?

Question

An applet developed outside our company just started failing for some users this week. Apparently it was because of the latest version of java (1.6u24) that auto updated. Is there a way to capture what version of java the user opened the applet with?

score 1 · Answer 1 · answered Mar 11 '11 at 17:04

1

You can use System.getProperty("java.version") to get that information. This is an example applet that uses it and the About page has the source.

answered Mar 11 '11 at 17:04

unholysampler

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Is there a way to write the data back to the server in a log file or something? I'm more interested in the developers knowing it than the end users. – xecaps12 Mar 11 '11 at 17:18
@xecaps12: You can do whatever you want with it once you get the value, it is just a String. Writing it to a log file seems like it would be the best solution. – unholysampler Mar 11 '11 at 17:51
I just wasn't sure if it'd write it to the log on the server, I thought it'd would be written on the client's machine. – xecaps12 Mar 11 '11 at 20:23
@xecaps12: I've never done anything with web applets, so I can't help you there. However, since it is running on the client's computer, I would guess that it would not write to the server and you will need to write a small bit of code to signal the server. – unholysampler Mar 11 '11 at 20:29

score 1 · Answer 2 · answered Mar 11 '11 at 17:06

1

You can use System.getProperty, specifically :

System.getProperty("java.version")

For a list of possible key value, see : getProperties()

answered Mar 11 '11 at 17:06

krtek

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score 0 · Answer 3 · answered Mar 11 '11 at 17:12

0

http://pscode.org/prop/?prop=java.version%2Cjava.vm.version

answered Mar 11 '11 at 17:12

Andrew Thompson

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score 0 · Accepted Answer · edited May 23 '17 at 12:19

Using the answers from another question, I ended up writing the code below. When the page loads, I get the user's java version then use an ajax call to save it where ever I need to. The part I used was the reference to the deployJava.js from Sun.

$(document).ready(function() {
    var jVersion = "";
    for (var i = 0; i < deployJava.getJREs().length; ++i) {
        jVersion += deployJava.getJREs()[i];
    }

    var url = 'saveJavaVersionAction.jsp';
    var params = 'version=' + jVersion;

    $.ajax({
        url: url,
        data: params,
        success: function(html) {
            $("#results").append(html);     
        }
    });

});

Can you capture end user's Java version when they run an applet?

4 Answers4