Develop Reference

Cannot get Java Applets to work in any browser

We are trying to download something from GE that uses Java to download when logging into the site. This is a windows 7 Professional PC. I have other computers that are able to do this successfully. Here is my order of operations:
Log into the site and select the file I want to download
Click download
It takes me to the page that says it will start in a few seconds but nothing happens. It is supposed to have a box that asks for Java to run.
I have reinstalled Java fresh and still nothing. Tried with multiple user accounts. Added the site to the list of exceptions in the firewalls and Java configuration. I have tried an earlier version of Java. This happens in Mozilla, Chrome and IE. I have made sure that the Java plugin shows up and is enabled. I just cant think of what I am missing. And since we are a contractor GE is not going to help us. Can anyone here think of anything?

Are you sure you have the Java plugin enabled? e.g. in Firefox, go to Settings, Plugins, and change Java Platform SE8 'Next Generation Java Plugin' to 'always activate'?

This sounds similar to the issues I had with Cisco WebVPN, Java-style. Once you have Java installed correctly and set as a plugin for any of the browsers you would like to use, see below.
Before you even start looking at browsers - if you think it is already set up correctly
Look at your Anti-Virus programs or anything else that could prevent it from working. McAfee Host Intrusion Protection is known to cause many Java programs to fail. Kapersky had issues, a while back, with Java on Windows (Java Applets not loading in Windows 8 ).
You must have a 64-bit browser to use 64-bit Java (also mentioned in the Chrome link below).
See below for any specific things that can be modified in the browser.
Chrome 43 is the more complicated browser to set up. They have a dedicated page with instructions.
How do I use Java with the Google Chrome browser?
Firefox 38 will prompt you.
In Internet Explorer 11, it's under Internet Options->Security. I recommend adding the hostname the applet is on as a Trusted Site (Select Trusted Sites and click the Sites button, then add the first part of the url). Click the Custom level button and make sure that Scripting of Java applets is not disabled.
If you still have problems with the applet:
Verify your Java version will work with the applet you are accessing
Verify the plugin is enabled for the browser through the Java Control Panel, which is available in Windows Control Panel, or on Mac/Linux, execute it from the JDK directory ($JAVA_HOME/ControlPanel ).

I ended up fixing the issue. I had to allow their UK site on the list for Java and enable the SSL 2.0 for HTTP in Java config as well

Java 7 Update 45 (64-bit) blocking java applet self signed

I'm seen this question, and I want know if this solution will work only on Java settings in my computer or this will work in all computers with Java installed? Because I want that my applet (.jar) works in all computers with Java installed, and with security settings default (High) that already comes when Java installed see.
Someone could give me a tip?
Thank in advance!

As the answer given into the post you have mentioned which is
Just Go To Startmenu >>Java >>Configure Java >> Security >> Edit site list >> copy and paste your Link with problem >> OK Problem fixed :)
This you have to do in each and every computer in which you want to run your applets , untill you are using self signed applets.
Alternative Solution : Just Use Signed Applets
Update
To understand the diffrence between Unsigned , Self-Signed and Signed Applets i suggest you to read this Java Applets: Unsigned vs Self-Signed vs Signed
In the java Update java7u51 Adding sites in exception list has been changed slightly , you may also look this post for that
Upcoming Exception Site List in 7u51

Specifying a JRE location for a JWS app launch

Is there a way to point to a specific JRE/JDK location to run a JWS application? I'm looking into specifying the actual location of the JRE, not only it's version via Java SE element of JNLP file. I dont want to access any system JRE, I only want to use whats bundled with my application.
Currently I am trying to bundle 1.6_45 with my app. However I am encountering issues when a user has 1.7_xx JRE installed on their system. It blocks the launch of the webstart application. The jars are self signed and getting them signed by a CA authority is not an option as it is too $$. I changed the j2se version tag in my jnlp to say 1.6* and this allowed it to run with 1.7_xx present. One bug squashed.
Now the issue is that systems are being upgraded to 1.6_71 [private oracle version], that apparently has some 1.7 security fixes backported in it. So now because of the jnlp tag having 1.6*, my app is picking up 1.6_71 and completely hanging. Webstart just opens the java console and hangs. I tried adding -Djnlpx.home to the jnlp java-vm-args, pointing to the bundled jre/bin, but no luck there.
One way I tried [from a post here on SO] is that I created a shortcut to my particular javaws passing the jnlp file location as a parameter. This did not work. It still picked up 1.6_71 and hung.
At this point, if I google anymore, its going to start showing me a captcha...sigh.
Any pointers are greatly appreciated! Thanks!

Is there a way to point to a specific JRE/JDK location to run a JWS application?
Short answer, no. Long answer, nope.

Oracle's latest release of Java 7 Update 51 includes new security changes that will block some applications. This is the new "security baseline" and there is apparently an equivalent code level for 1.6.
One of the configuration options that helps determine what exactly happens is the Security Level, found in the Security tab from (Windows) Control Panel -> Java. If you set the security level at it's lowest (can't remember the name) then you might not get blocked. Security level High will block unsigned and self-signed. Security Level Very High will be even more restrictive, like blocking an expired application - meaning the certificate has expired.
Also, maybe you could try setting the specific level of the JRE you want to run - see the link
http://docs.oracle.com/javase/6/docs/technotes/guides/javaws/developersguide/syntax.html#jnlp
for more info.

Java applets taking too much time to load

I am using the Sentinel EMS from Safenet. The local tomcat6 website uses the java applets for their hardware key management. I installed the latest jre7 u45 from java.com. My problem is the java applets are taking too much time to load in an offline environment (applet shows the progress bar about 8 - 10 minutes). When the machine is connected to internet, the applets will load in less than 1 minute. Is there any setting to change the behaviour of java or is it a problem of tomcat?
Note:The safenet people replied it is the problem of jre installation and I need to re-install. I did re install 2-3 times, but no chance to rectify the problem.

I think there is some gap in communication . I am trying to answer your question below, hope this helps
Certificate verification is recommended by JAVA since JRE 7 update 25 for security reasons, you can visit http://www.java.com/en/download/help/revocation_options.xml
There is a Workaround which is not recommended by Java
Open Control Panel
Open Java
Goto Advance Settings
Find "Perform certificate revocation checks on"
Select "Do not check (Not Recommended)"
Click Ok
After this restart all Browser instances
Note :- For Intranet or Localhost you can use this workaround as you know that certificates are valid, but for internet please revert back to default settings
I am from Safenet QA

Java Applet is not running in a browser

I am trying to run my applet in a browser, chrome/IE but I get the following message:
Your security settings have blocked a local application from running
Due to Oracle, changing security level in java control panel from high to medium will solve the issue, but it does not. I have even tried the low level, and custom level too enabling all applications to run without any prompt. I have also changed the advanced setting to allow unsigned applets to run.
It does not work in any way.
Any help is appreciated.

Do the following
Go to IE
Tools -> Internet Options
Go to the Advanced Tab
Under Java(Sun) Select the check box saying 'Use JRE ... for applet' (requires restart)
Select Apply/Ok. Restart IE and try loading the applet again.

You can either make sure that the applet is signed by a valid cert, and it is not a self-signed cert. Or if you just want to bypass the warning, you can add the domain address to Exception Site List.
Java Control Panel -> Security tab -> Exception Site List
and also you may also try to add the website to the Trusted Zone in your IE if you are sure that the website is safe. In Trusted Zone, there are fewer restrictions to block you from running applet and running the out-of-date ActiveX.