Im curious as to which one I should be using. When i open code examples from the jdk using notepad, the code is just a jarbled mess. You can still pick out the code but it is annoying. Maybe im missing, i don't know.
For windows there is EditPad Pro which is a great text editor with syntax highlighting/coloring, phenomenal regular expression support, and some other great features. (You can even create your own color schemes if you don;t like the one's it comes with.) It is commercial and needs to be purchased, but is well worth the money. (There is a free trial version available). I've used EditPad pro for seven years now and love it. There is EditPad Lite which is free, but it lacks the syntax highlighting.
There's also jEdit. It's written in Java, so it runs on Windows, Mac, Linux and Unix. So an advantage it has is you can have a consistent editor on all platforms. It's an editor geared towards programmers, so it has "knowledge of" most languages, and has a lot of features. But that strength (lots of features) can also be a weakness in that some people find it a little daunting at first. It's open source and free to use.
As sometimes the java code is saved as "text with UNICODE" , and that Notpead dosent support unicode format, So try using a next editor just below to Notepad . i.e 'WordPad' , which opens your java code as it is with support to indention .