For a while, Java had some security issues. As you noted, they were fixed… but not really. In fact, I still recommend avoiding Java, if possible. Uninstalling Java is the safest situation to be in; I don’t expect that to change any time soon.
But, I agree. Java can be a tad confusing because there are several parts to it.
The problem with Java
Java is fixing their issues, but as they do, others are finding new problems, vulnerabilities, and bugs at roughly the same rate. And there are malware developers out there taking advantage of that. So while you might hear that bugs are being fixed, and that might even be true, that doesn’t mean everything is better.
But if a program requires Java, you need to use it. If this is your situation, I hope you are taking appropriate precautions.
Different versions of Java
One thing to remember is that the Java in your browser and the Java on your computer are actually two slightly different, yet related things.
When you install Java from within the web browser, it’s installing those components for the web browser. In fact, it’s probably installing the components for only that particular web browser.
In your case, if you’re running Opera and you install Java, it’s possible that Java was not installed in Internet Explorer, Firefox, Chrome, or any other browser installed on your machine.
On top of that, many games and Java-based applications aren’t browser based; they’re actually Windows programs. Installing Java into your browser doesn’t necessarily install Java in Windows itself.
How to install Java
Rather than allowing the browser to install Java for you because it says there’s a plug in missing, go to Java.com and download the program there. It should install Java on your system as well as on every browser on your system.
Again, that is only if you have to do this.
I’m still uncomfortable with saying Java is safe because ongoing reports are simply that it is not. Even if they’re fixing bugs, there are enough new vulnerabilities being found in Java on a regular basis that it’s still vulnerable.
If you can avoid Java, you should.