Super fast and simple evaluator for mathematical expressions written in Java. More background information can be found in this blog post: http://andreas.haufler.info/2013/12/how-to-write-one-of-fastest-expression.html
Using it is as simple as:
Scope scope = Scope.create();
Variable a = scope.getVariable("a");
Expression expr = Parser.parse("3 a * 4", scope);
a.setValue(4);
System.out.println(expr.evaluate());
a.setValue(5);
System.out.println(expr.evaluate());
For your convenience: A pre-built jar can be found in the build directory.
parsii is part of the open source initiative of scireum GmbH (http://www.scireum.de)
Check out or micro kernel called SIRIUS: https://github.com/scireum/sirius
parsii is available under https://mvn.scireum.com.
<dependency>
<groupId>com.scireum</groupId>
<artifactId>parsii</artifactId>
<version>...</version>
</dependency>