What editor is as good as TextPad for compiling and running Java programs? [duplicate]

Geany

From the official site:

Geany is a text editor using the GTK2 toolkit with basic features of an integrated development environment. It was developed to provide a small and fast IDE, which has only a few dependencies from other packages. It supports many filetypes and has some nice features.

jEdit

Additionally, jEdit (man page) seems to be another excellent option for your tasks.

From the man site:

jEdit is a cross-platform text editor written in Java. It has an extensive feature set that includes syntax highlighting, auto indent, folding, word wrap, abbreviation expansion, multiple clipboards, powerful search and replace and much more.

Furthermore, jEdit is extremely customizable, and extensible, using either macros written in the BeanShell scripting language, or plugins written in Java. With plugins, you can create a very powerful development environment for HTML, XML, C/C++, Python, Perl, Ruby, Lisp, Scheme, and many others.

jEdit Requires Sun Java 2 version 1.5.

jEdit is released under the GNU General Public License, which can be found in the online help.

I suggest Eclipse! It have a lot of documentation in diferent languages and it's a wonderfull IDE