A JDK installation and a text editor are the bare minimum for Java development. (It is nice to have a text editor that can do Java syntax highlighting, but you can do without.)

However for serious development work it is recommended that you also use the following:

• A Java IDE such as Eclipse, Intellij IDEA or NetBeans
• A Java build tool such as Ant, Gradle or Maven
• A version control system for managing your code base (with appropriate backups, and off-site replication)
• Test tools and CI (continuous integration) tools