This tutorial from Make Tech Easier shows you how to install the java development kit on your raspberry pi:
The Java programming language was first released back in 1995, and since then it has grown to become a giant among giants. According to Oracle, there are more than 9 million Java developers worldwide. And because of Android, there are millions of smartphones which run Java, while simultaneously every Blu-ray player in the world ships with Java. Last, but not least, Java is available for the Raspberry Pi!
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