JUEL is an open source and free implementation of the Unified Expression Language (EL), specified as part of the JSP 2.1 standard (JSR-245). JUEL can be used as a standalone EL implementation or with Sun`s GlassFish V2.
Once, the EL started as part of JSTL. Then, the EL made its way into the JSP 2.0 standard. Now, though part of JSP 2.1, the EL API has been separated into package javax.el and all dependencies to the core JSP classes have been removed.
In other words: the EL is ready for use in non-JSP applications!
JUEL provides a lightweight and efficient implementation of the Unified Expression Language.
Here are some key features of "JUEL":
· High Performance ??? Parsing expressions is certainly the expected performance bottleneck. JUEL uses a hand-coded parser which is up to 10 times faster than the previously used (javacc) generated parser! Once built, expression trees are evaluated at highest speed.
· Pluggable Cache ??? Even if JUELs parser is fast, parsing expressions is relative expensive. Therefore, it`s best to parse an expression string only once. JUEL provides a default caching mechanism which should be sufficient in most cases. However, JUEL allows to plug in your own cache easily.
· Small Footprint ??? JUEL has been carefully designed to minimize memory usage as well as code size.
· Method Invocations ??? As an extension to the standard, JUEL can be configured to enable method invocations as in ${foo.matches(`[0-9]+`)}.
· VarArg Calls ??? As another extension to the standard, JUEL can be configured to support Java 5 VarArgs. E.g., binding String.format(String, String...) to function format allows for ${format(`Hey %s`,`Joe`)}.
· Pluggable EL??? The JUEL jar has been setup to be transparently detected as EL implementation by a Java runtime environment or JEE5 application server. Using JUEL does not require an application to explicitly reference any of the JUEL specific implementation classes.
What`s New in This Release: [ read full changelog ]
· Maintenance release which fixes a problem related to method invocations/expressions.
