JSR 331 “Java Constraint Programming API“ is a JCP Specification Standard that has been developed under the terms of the www.JCP.org. JSR331 Standard was officially approved by the JCP Executive Committee on March-2012 as the Final Release and since then it is in the maintenance mode.
This website describes the latest state of the standard and provides access to its various implementations using constraint and linear solvers.
Since 2020 JSR-331 is available through public GitHub and MVN repositories and several new implementations have been added.
Java Solver. The simplest way to incorporate JSR-331 into your Java application is through Java Solver freely available at http://JavaSolver.com.
Rule Solver. This product available from http://RuleSolver.com is a part of the popular Decision Intelligence Software known as OpenRules. It provide a business interface to optimization solvers for business analysts and does not require knowledge of Java.
If you have any technical questions, please post them at JSR-331 Support Forum. You may also send questions and comments directly to the JSR-331 Specification Lead.
JSR331 Implementations
JCP Standard JSR 331: Java Constraint Programming API 