Package org.jruby.runtime.load

Class LoadService

java.lang.Object
org.jruby.runtime.load.LoadService
Direct Known Subclasses:
OSGiLoadService
public class LoadService extends Object

How require works in JRuby

When requiring a name from Ruby, JRuby will first remove any file extension it knows about, thereby making it possible to use this string to see if JRuby has already loaded the name in question. If a .rb extension is specified, JRuby will only try those extensions when searching. If a .so, .o, .dll, or .jar extension is specified, JRuby will only try .so or .jar when searching. Otherwise, JRuby goes through the known suffixes (.rb, .rb.ast.ser, .so, and .jar) and tries to find a library with this name. The process for finding a library follows this order for all searchable extensions:
  1. First, check if the name starts with 'jar:', then the path points to a jar-file resource which is returned.
  2. Second, try searching for the file in the current dir
  3. Then JRuby looks through the load path trying these variants:
    1. See if the current load path entry starts with 'jar:', if so check if this jar-file contains the name
    2. Otherwise JRuby tries to construct a path by combining the entry and the current working directy, and then see if a file with the correct name can be reached from this point.
  4. If all these fail, try to load the name as a resource from classloader resources, using the bare name as well as the load path entries
  5. When we get to this state, the normal JRuby loading has failed. At this stage JRuby tries to load Java native extensions, by following this process:
    1. First it checks that we haven't already found a library. If we found a library of type JarredScript, the method continues.
    2. The first step is translating the name given into a valid Java Extension class name. First it splits the string into each path segment, and then makes all but the last downcased. After this it takes the last entry, removes all underscores and capitalizes each part separated by underscores. It then joins everything together and tacks on a 'Service' at the end. Lastly, it removes all leading dots, to make it a valid Java FWCN.
    3. If the previous library was of type JarredScript, we try to add the jar-file to the classpath
    4. Now JRuby tries to instantiate the class with the name constructed. If this works, we return a ClassExtensionLibrary. Otherwise, the old library is put back in place, if there was one.
  6. When all separate methods have been tried and there was no result, a LoadError will be raised.
  7. Otherwise, the name will be added to the loaded features, and the library loaded