from:http://www.csdn.net/article/2015-03-26/2824317
1. notepad++
notepad++ is the best tool for editing XML, scripting, and taking notes. The best part of this tool is that any document you open on the notepad++ will have a residual document after it has been closed, which helps to delete important documents accidentally and recover. Notepad++ is a very special editor, open source software, free to use.
2. XML Marker
The XML marker tool is very important for Java programmers. It helps developers get the job done better. XML marker is an XML editor that uses synchronized tables, trees, and text displays to display the nature of hierarchical and XML data tables. It is automatically generated by collecting duplicate attributes and label names, and then arranging them to appear in any selected tab table of the column.
3. SQL Developer
This is a free tool for database administrators, and you can use this tool to link databases and SQL statements. It doesn't function as much as toad, but it's enough for you to use. The only drawback to this tool is that you need a JDK when you use it.
4. Jad
Jad is used to decompile Java classes. You can use Jad to command and read the code in plain text form.
5. Eclipse
Eclipse is an open-source, Java-based, extensible development platform. For its part, it is just a framework and a set of services for building a development environment through plug-in components. Fortunately, Eclipse comes with a standard set of plugins, including Java development tools.
6. Keytool
Keytool is part of the Oracle JDK. Keytool is rarely used in development environments, but if you are developing an enterprise application, this will be your best key and certificate management tool.
Java Developer Tools