Hi Henry! thanks for your interest :) I avoided even reading the Jersey source code for the problem you mentioned (I'm not licensing expert but AFAIK ASL2.0 is not compatible with Jersey's), I took the main inspiration from Misko Hevery's classpath-explorer (ASL2.0) for the ClassPath structure/bootstrap and MyBatis (I'm committer also in this project) and Google Guice (both ASL2.0) for the Test/Matcher design (I renamed them Filter). Said that, do you see any potential to start importing that stuff in Lang? Many thanks in advance, have a nice day, Simo
http://people.apache.org/~simonetripodi/ http://www.99soft.org/ On Mon, Sep 13, 2010 at 7:27 AM, Henri Yandell <flame...@gmail.com> wrote: > I like the sound of it :) > > I hope you've not used any code from Jersey though, it's license will > overrule the AL 2.0 licensing. > > Hen > > On Sun, Sep 12, 2010 at 7:42 AM, Simone Tripodi > <simone.trip...@gmail.com> wrote: >> Hi all guys, >> during my last year of work I've met a replicated behavior in >> different projects, like the classpath analysis. Scanning the >> classpath could be useful to dynamically find services implementations >> or to generate custom documentation, or some other uses nobody has not >> envisioned yet. >> Follow below a short list of met use cases: >> >> - Misko Hevery of Google developed a light yet powerful classpath >> explorer, but it seems the project has a very low activity, you can >> find more info on http://code.google.com/p/classpath-explorer/; >> >> - The MyBatis (formerly Apache iBatis) project added an utility class >> to discover MyBatis components from the classpath >> (http://code.google.com/p/mybatis/source/browse/trunk/src/main/java/org/apache/ibatis/io/ResolverUtil.java) >> >> - The Jersey (JAX-RS) project has a config parameter, >> "com.sun.jersey.config.property.packages", where users can specify >> packages where look for JSR311 components, like showed at "1.2. >> Deploying the root resource" on >> https://jersey.dev.java.net/nonav/documentation/latest/user-guide.html >> >> For this reason, I think that something from the threes can be reused >> and improved to create a common stuff to scan the classpath. >> >> First of all, no more package-based filter policy only, but rather >> something closer to an expression language, like >> >> ---- >> Filter filter = and( >> inSubpackage("com.acme"), >> isPublic(), >> not(isAbstract()), >> not(isAnnotation()), >> not(classNameMatches(".*TestCase")); >> ---- >> >> Second, since analyzing the classpath is an operation that could take >> a long time, I think that the "scan" operation should accept one (or >> optionally more) classpath handler, each one accepts one filter (as >> described above) associated to one (or optionally more) classpath >> entry handler. To be more clear, I'd like to show an example: >> >> ---- >> scan(new ClassPathHandler(and( >> inSubpackage("com.acme"), >> isPublic(), >> not(isAbstract()), >> not(isAnnotation()), >> not(classNameMatches(".*TestCase"))), >> new ClassPathEntryHandler() { >> >> public void doHandle(ClassPathEntry classPathEntry) { >> Class<?> type = classPathEntry.getClazz(); >> // manipulate the class >> } >> >> }, >> new ClassPathEntryHandler() { >> >> public void doHandle(ClassPathEntry classPathEntry) { >> if (log.isInfoEnabled()) { >> log.info("Plugged in my ACME system " + >> classPathEntry); >> } >> } >> >> } >> ), new ClassPathHandler(any(), new ClassPathEntryHandler() { >> >> public void doHandle(ClassPathEntry classPathEntry) { >> if (log.isDebugEnabled()) { >> log.debug("Plugged class " + classPathEntry); >> } >> } >> >> })) >> ---- >> >> Finally, the bootstrap: >> * a classpath could be created starting from the JVM one (the >> System.getProperty("java.class.path")) or from a custom one (like the >> one in a Servlet context); >> * a custom ClassLoader or the default >> Thread.currentThread().getContextClassLoader() is needed to resolve >> classpath entries to Class<?> object; >> * an error Handler (a default one is provided) is needed to catch >> eventual errors that could occur while scanning the classpath. >> That could be resumed in a chained builders, like: >> >> ---- >> ClassPath classPath = new ClassPathBuilder() >> .createFromJVM() >> .usingDefaultClassLoader() >> .usingDefaultErrorHandler(); >> ---- >> >> A codebase for this already exists, I committed it on Google-Code >> (http://code.google.com/p/meiyo/) and licensed it under ASL2.0. If you >> guys agree I'd be more than happy to port it under Commons-Lang (at >> least my instinct suggested Lang as the better place). >> >> WDYT? Thanks in advance and thanks for reading, I hop you'ven't got bored :P >> Have a nice day, >> Simo >> >> http://people.apache.org/~simonetripodi/ >> http://www.99soft.org/ >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >> For additional commands, e-mail: dev-h...@commons.apache.org >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
