The Wolfram Language's J/Link system provides a uniquely seamless interface to the Java environment. With J/Link you can immediately access Java classes and objects from within the Wolfram Language without any Java programming. J/Link also provides a complete library for calling the Wolfram Language from within Java programs.

Calling Java from the Wolfram Language »

LoadJavaClass — load and set up a Java class for use from the Wolfram Language

JavaNew — create a Java object

JavaObject  ▪  JavaBlock  ▪  ...

Calling the Wolfram Language from Java »

KernelLink  ▪  MathLink  ▪  Expr  ▪  MathGraphicsJPanel  ▪  ...