private static boolean implementsLogFactory()

in src/main/java/org/apache/commons/logging/LogFactory.java [1176:1226]
33 lines of code
7 McCabe index (conditional complexity)

    private static boolean implementsLogFactory(final Class logFactoryClass) {
        boolean implementsLogFactory = false;
        if (logFactoryClass != null) {
            try {
                final ClassLoader logFactoryClassLoader = logFactoryClass.getClassLoader();
                if (logFactoryClassLoader == null) {
                    logDiagnostic("[CUSTOM LOG FACTORY] was loaded by the boot classloader");
                } else {
                    logHierarchy("[CUSTOM LOG FACTORY] ", logFactoryClassLoader);
                    final Class factoryFromCustomLoader
                        = Class.forName("org.apache.commons.logging.LogFactory", false, logFactoryClassLoader);
                    implementsLogFactory = factoryFromCustomLoader.isAssignableFrom(logFactoryClass);
                    if (implementsLogFactory) {
                        logDiagnostic("[CUSTOM LOG FACTORY] " + logFactoryClass.getName() +
                                      " implements LogFactory but was loaded by an incompatible classloader.");
                    } else {
                        logDiagnostic("[CUSTOM LOG FACTORY] " + logFactoryClass.getName() +
                                      " does not implement LogFactory.");
                    }
                }
            } catch (final SecurityException e) {
                //
                // The application is running within a hostile security environment.
                // This will make it very hard to diagnose issues with JCL.
                // Consider running less securely whilst debugging this issue.
                //
                logDiagnostic("[CUSTOM LOG FACTORY] SecurityException thrown whilst trying to determine whether " +
                              "the compatibility was caused by a classloader conflict: " + e.getMessage());
            } catch (final LinkageError e) {
                //
                // This should be an unusual circumstance.
                // LinkageError's usually indicate that a dependent class has incompatibly changed.
                // Another possibility may be an exception thrown by an initializer.
                // Time for a clean rebuild?
                //
                logDiagnostic("[CUSTOM LOG FACTORY] LinkageError thrown whilst trying to determine whether " +
                              "the compatibility was caused by a classloader conflict: " + e.getMessage());
            } catch (final ClassNotFoundException e) {
                //
                // LogFactory cannot be loaded by the classloader which loaded the custom factory implementation.
                // The custom implementation is not viable until this is corrected.
                // Ensure that the JCL jar and the custom class are available from the same classloader.
                // Running with diagnostics on should give information about the classloaders used
                // to load the custom factory.
                //
                logDiagnostic("[CUSTOM LOG FACTORY] LogFactory class cannot be loaded by classloader which loaded " +
                              "the custom LogFactory implementation. Is the custom factory in the right classloader?");
            }
        }
        return implementsLogFactory;
    }