Class ClassLoaders


  • public final class ClassLoaders
    extends java.lang.Object
    Utility methods around the ClassLoader.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.ClassLoader BOOTCLASSPATH_CLASS_LOADER
      The ClassLoader that loads the classes on the currently executing JVM's "boot class path", i.e. the JARs in the JRE's "lib" and "lib/ext" directories, but not the JARs and class directories specified through the --classpath command line option.
      static java.lang.ClassLoader CLASSPATH_CLASS_LOADER
      The ClassLoader that loads the classes on the currently executing JVM's "class path", i.e. the JARs in the JRE's "lib" and "lib/ext" directories, and the JARs and class directories specified through the class path.
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.lang.ClassLoader getsResourceAsStream​(ResourceFinder finder, java.lang.ClassLoader parent)
      Creates and returns a ClassLoader that implements ClassLoader.getResourceAsStream(String) via a ResourceFinder.
      static java.util.Map<java.lang.String,​java.net.URL> getSubresources​(java.lang.ClassLoader classLoader, java.lang.String name, boolean includeDirectories, boolean recurse)
      Returns a name-to-URL mapping of all resources "under" a given directory name.
      static java.util.Map<java.lang.String,​java.net.URL> getSubresourcesOf​(java.net.URL root, java.lang.String rootName, boolean includeDirectories, boolean recurse)
      Returns a name-to-URL mapping of all resources "under" a given root resource.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • CLASSPATH_CLASS_LOADER

        public static final java.lang.ClassLoader CLASSPATH_CLASS_LOADER
        The ClassLoader that loads the classes on the currently executing JVM's "class path", i.e. the JARs in the JRE's "lib" and "lib/ext" directories, and the JARs and class directories specified through the class path.
      • BOOTCLASSPATH_CLASS_LOADER

        public static final java.lang.ClassLoader BOOTCLASSPATH_CLASS_LOADER
        The ClassLoader that loads the classes on the currently executing JVM's "boot class path", i.e. the JARs in the JRE's "lib" and "lib/ext" directories, but not the JARs and class directories specified through the --classpath command line option.
    • Method Detail

      • getsResourceAsStream

        public static java.lang.ClassLoader getsResourceAsStream​(ResourceFinder finder,
                                                                 @Nullable
                                                                 java.lang.ClassLoader parent)
        Creates and returns a ClassLoader that implements ClassLoader.getResourceAsStream(String) via a ResourceFinder.

        ClassLoader.getResource(String) returns a non-null value iff then resoure finder finds a LocatableResource.

        Notice that ClassLoader.getResources(String) is not overridden.

      • getSubresources

        public static java.util.Map<java.lang.String,​java.net.URL> getSubresources​(@Nullable
                                                                                         java.lang.ClassLoader classLoader,
                                                                                         java.lang.String name,
                                                                                         boolean includeDirectories,
                                                                                         boolean recurse)
                                                                                  throws java.io.IOException
        Returns a name-to-URL mapping of all resources "under" a given directory name.

        Iff the name does not end with a slash, then calling this method is equivalent with calling ClassLoader.getResource(String).

        Otherwise, if the name does end with a slash, then this method returns a name-to-URL mapping of all content resources who's names begin with the given name. Iff recurse is false, then only immediate subresources are included. Iff includeDirectories is true, then also directory resources are included in the result set; their names all ending with a slash.

        If multiple resources have the name, then the resources are retrieved from the first occurrence.

        Parameters:
        classLoader - The class loader to use; null means use the system class loader
        name - No leading slash
        Returns:
        Keys ending with a slash map to "directory resources", the other keys map to "content resources"
        Throws:
        java.io.IOException
      • getSubresourcesOf

        public static java.util.Map<java.lang.String,​java.net.URL> getSubresourcesOf​(java.net.URL root,
                                                                                           java.lang.String rootName,
                                                                                           boolean includeDirectories,
                                                                                           boolean recurse)
                                                                                    throws java.io.IOException
        Returns a name-to-URL mapping of all resources "under" a given root resource.

        If the root designates a "content resource" (as opposed to a "directory resource"), then the method returns Collections.singletonMap(name, rootName).

        Otherwise, if the root designates a "directory resource", then this method returns a name-to-URL mapping of all content resources that are located "under" the root resource. Iff recurse is false, then only immediate subresources are included. Iff includeDirectories is true, then directory resources are also included in the result set; their names all ending with a slash.

        Returns:
        Keys ending with a slash map to "directory resources", the other keys map to "content resources"
        Throws:
        java.io.IOException