static T find()

in saaj-api-1.4/src/main/java/javax/xml/soap/FactoryFinder.java [93:175]
63 lines of code
15 McCabe index (conditional complexity)

    static <T> T find(Class<T> factoryClass,
                      String defaultClassName,
                      boolean tryFallback, String deprecatedFactoryId) throws SOAPException {

        ClassLoader tccl = ServiceLoaderUtil.contextClassLoader(EXCEPTION_HANDLER);
        String factoryId = factoryClass.getName();

        try {
            // If we are deployed into an OSGi environment, leverage it
            if (factoryClass == null) {
                String factoryClassName = factoryClass.getName();
                if (factoryClassName.equals("javax.xml.soap.MetaFactory")) {
                    //this is an exception that the factoryPropertyName isn't
                    //the actual factory class name, there is no class
                    //javax.xml.soap.MetaFactory at all
                    factoryClassName = "javax.xml.soap.SAAJMetaFactory";
                }
                ClassLoader cl = FactoryFinder.class.getClassLoader();
                if (cl == null) {
                    cl = Thread.currentThread().getContextClassLoader();
                }
                factoryClass = (Class<T>)cl.loadClass(factoryClassName);
            }
            Class spiClass = org.apache.servicemix.specs.locator.OsgiLocator.locate(factoryClass, factoryClass.getName());
            if (spiClass != null) {
                return (T)spiClass.newInstance();
            }
        } catch (Throwable e) {
        }


        // Use the system property first
        String className = fromSystemProperty(factoryId, deprecatedFactoryId);
        if (className != null) {
            Object result = newInstance(className, defaultClassName, tccl);
            if (result != null) {
                return (T) result;
            }
        }

        // try to read from $java.home/lib/jaxm.properties
        className = fromJDKProperties(factoryId, deprecatedFactoryId);
        if (className != null) {
            Object result = newInstance(className, defaultClassName, tccl);
            if (result != null) {
                return (T) result;
            }
        }

        // standard services: java.util.ServiceLoader
        T factory = ServiceLoaderUtil.firstByServiceLoader(
                factoryClass,
                logger,
                EXCEPTION_HANDLER);
        if (factory != null) {
            return factory;
        }

        // try to find services in CLASSPATH
        className = fromMetaInfServices(deprecatedFactoryId, tccl);
        if (className != null) {
            logger.log(Level.WARNING,
                    "Using deprecated META-INF/services mechanism with non-standard property: {0}. " +
                            "Property {1} should be used instead.",
                    new Object[]{deprecatedFactoryId, factoryId});
            Object result = newInstance(className, defaultClassName, tccl);
            if (result != null) {
                return (T) result;
            }
        }

        // If not found and fallback should not be tried, return a null result.
        if (!tryFallback)
            return null;

        // We didn't find the class through the usual means so try the default
        // (built in) factory if specified.
        if (defaultClassName == null) {
            throw new SOAPException(
                    "Provider for " + factoryId + " cannot be found", null);
        }
        return (T) newInstance(defaultClassName, defaultClassName, tccl);
    }