private static Object findJarServiceProvider()

in jaxp-api-1.4/src/main/java/javax/xml/datatype/FactoryFinder.java [270:344]
54 lines of code
13 McCabe index (conditional complexity)

    private static Object findJarServiceProvider(String factoryId)
        throws ConfigurationError
    {

        String serviceId = "META-INF/services/" + factoryId;
        InputStream is = null;

        // First try the Context ClassLoader
        ClassLoader cl = SecuritySupport.getContextClassLoader();
        if (cl != null) {
            is = SecuritySupport.getResourceAsStream(cl, serviceId);

            // If no provider found then try the current ClassLoader
            if (is == null) {
                cl = FactoryFinder.class.getClassLoader();
                if (cl == null) {
                    cl = ClassLoader.getSystemClassLoader();
                }
                is = SecuritySupport.getResourceAsStream(cl, serviceId);
            }
        } else {
            // No Context ClassLoader, try the current
            // ClassLoader
            cl = FactoryFinder.class.getClassLoader();
            if (cl == null) {
                cl = ClassLoader.getSystemClassLoader();
            }
            is = SecuritySupport.getResourceAsStream(cl, serviceId);
        }

        if (is == null) {
            // No provider found
            return null;
        }

        if (debug) debugPrintln("found jar resource=" + serviceId +
               " using ClassLoader: " + cl);

        BufferedReader rd;
        try {
            rd = new BufferedReader(new InputStreamReader(is, "UTF-8"), DEFAULT_LINE_LENGTH);
        } catch (java.io.UnsupportedEncodingException e) {
            rd = new BufferedReader(new InputStreamReader(is), DEFAULT_LINE_LENGTH);
        }
        
        String factoryClassName = null;
        try {
            // XXX Does not handle all possible input as specified by the
            // Jar Service Provider specification
            factoryClassName = rd.readLine();
        } 
        catch (IOException x) {
            // No provider found
            return null;
        }
        finally {
            try { 
                // try to close the reader. 
                rd.close(); 
            } 
            // Ignore the exception. 
            catch (IOException exc) {}
        }

        if (factoryClassName != null &&
            ! "".equals(factoryClassName)) {
            if (debug) debugPrintln("found in resource, value="
                   + factoryClassName);

            return newInstance(factoryClassName, cl);
        }

        // No provider found
        return null;
    }