diff options
Diffstat (limited to 'sandbox/SPI/implementation-spi-impl/src/main/java/org/apache/tuscany/spi/implementation/impl/Discovery.java')
-rw-r--r-- | sandbox/SPI/implementation-spi-impl/src/main/java/org/apache/tuscany/spi/implementation/impl/Discovery.java | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/sandbox/SPI/implementation-spi-impl/src/main/java/org/apache/tuscany/spi/implementation/impl/Discovery.java b/sandbox/SPI/implementation-spi-impl/src/main/java/org/apache/tuscany/spi/implementation/impl/Discovery.java new file mode 100644 index 0000000000..ba3392795a --- /dev/null +++ b/sandbox/SPI/implementation-spi-impl/src/main/java/org/apache/tuscany/spi/implementation/impl/Discovery.java @@ -0,0 +1,98 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.tuscany.spi.implementation.impl; + +import java.io.BufferedReader; +import java.io.IOException; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.net.URL; +import java.util.ArrayList; +import java.util.Collection; +import java.util.Enumeration; +import java.util.HashSet; +import java.util.List; +import java.util.Set; + +import org.apache.tuscany.core.util.IOHelper; + +public class Discovery { + + /** + * Read the service name from a configuration file + * + * @param classLoader + * @param name The name of the service class + * @return A class name which extends/implements the service class + * @throws IOException + */ + private static Set<String> getServiceNames(ClassLoader classLoader, String name) throws IOException { + Set<String> set = new HashSet<String>(); + Enumeration<URL> urls = classLoader.getResources("META-INF/services/" + name); + while (urls.hasMoreElements()) { + URL url = urls.nextElement(); + Set<String> service = getServiceNames(url); + if (service != null) { + set.addAll(service); + + } + } + return set; + } + + private static Set<String> getServiceNames(URL url) throws IOException { + Set<String> names = new HashSet<String>(); + InputStream is = IOHelper.getInputStream(url); + BufferedReader reader = null; + try { + reader = new BufferedReader(new InputStreamReader(is)); + while (true) { + String line = reader.readLine(); + if (line == null) { + break; + } + line = line.trim(); + if (!line.startsWith("#") && !"".equals(line)) { + names.add(line.trim()); + } + } + } finally { + if (reader != null) { + reader.close(); + } + } + return names; + } + + public static <T> Collection<T> getInstances(final ClassLoader classLoader, Class<T> serviceClass) { + List<T> instances = new ArrayList<T>(); + try { + Set<String> services = getServiceNames(classLoader, serviceClass.getName()); + for (String className : services) { + Class cls = Class.forName(className, true, classLoader); + instances.add(serviceClass.cast(cls.newInstance())); // NOPMD + } + } catch (Exception e) { + throw new IllegalStateException(e); + } + return instances; + } + +} |