| /* |
| * 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.dubbo.common.extension; |
| |
| import org.apache.dubbo.common.URL; |
| import org.apache.dubbo.common.context.Lifecycle; |
| import org.apache.dubbo.common.extension.support.ActivateComparator; |
| import org.apache.dubbo.common.extension.support.WrapperComparator; |
| import org.apache.dubbo.common.lang.Prioritized; |
| import org.apache.dubbo.common.logger.Logger; |
| import org.apache.dubbo.common.logger.LoggerFactory; |
| import org.apache.dubbo.common.utils.ArrayUtils; |
| import org.apache.dubbo.common.utils.ClassUtils; |
| import org.apache.dubbo.common.utils.CollectionUtils; |
| import org.apache.dubbo.common.utils.ConcurrentHashSet; |
| import org.apache.dubbo.common.utils.ConfigUtils; |
| import org.apache.dubbo.common.utils.Holder; |
| import org.apache.dubbo.common.utils.ReflectUtils; |
| import org.apache.dubbo.common.utils.StringUtils; |
| |
| import java.io.BufferedReader; |
| import java.io.InputStreamReader; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.nio.charset.StandardCharsets; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.Enumeration; |
| import java.util.HashMap; |
| import java.util.LinkedHashSet; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.ServiceLoader; |
| import java.util.Set; |
| import java.util.TreeSet; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.regex.Pattern; |
| |
| import static java.util.Arrays.asList; |
| import static java.util.Collections.sort; |
| import static java.util.ServiceLoader.load; |
| import static java.util.stream.StreamSupport.stream; |
| import static org.apache.dubbo.common.constants.CommonConstants.COMMA_SPLIT_PATTERN; |
| import static org.apache.dubbo.common.constants.CommonConstants.DEFAULT_KEY; |
| import static org.apache.dubbo.common.constants.CommonConstants.REMOVE_VALUE_PREFIX; |
| |
| /** |
| * {@link org.apache.dubbo.rpc.model.ApplicationModel}, {@code DubboBootstrap} and this class are |
| * at present designed to be singleton or static (by itself totally static or uses some static fields). |
| * So the instances returned from them are of process or classloader scope. If you want to support |
| * multiple dubbo servers in a single process, you may need to refactor these three classes. |
| * <p> |
| * Load dubbo extensions |
| * <ul> |
| * <li>auto inject dependency extension </li> |
| * <li>auto wrap extension in wrapper </li> |
| * <li>default extension is an adaptive instance</li> |
| * </ul> |
| * |
| * @see <a href="http://java.sun.com/j2se/1.5.0/docs/guide/jar/jar.html#Service%20Provider">Service Provider in Java 5</a> |
| * @see org.apache.dubbo.common.extension.SPI |
| * @see org.apache.dubbo.common.extension.Adaptive |
| * @see org.apache.dubbo.common.extension.Activate |
| */ |
| public class ExtensionLoader<T> { |
| |
| private static final Logger logger = LoggerFactory.getLogger(ExtensionLoader.class); |
| |
| private static final Pattern NAME_SEPARATOR = Pattern.compile("\\s*[,]+\\s*"); |
| |
| private static final ConcurrentMap<Class<?>, ExtensionLoader<?>> EXTENSION_LOADERS = new ConcurrentHashMap<>(64); |
| |
| private static final ConcurrentMap<Class<?>, Object> EXTENSION_INSTANCES = new ConcurrentHashMap<>(64); |
| |
| private final Class<?> type; |
| |
| private final ExtensionFactory objectFactory; |
| |
| private final ConcurrentMap<Class<?>, String> cachedNames = new ConcurrentHashMap<>(); |
| |
| private final Holder<Map<String, Class<?>>> cachedClasses = new Holder<>(); |
| |
| private final Map<String, Object> cachedActivates = new ConcurrentHashMap<>(); |
| private final ConcurrentMap<String, Holder<Object>> cachedInstances = new ConcurrentHashMap<>(); |
| private final Holder<Object> cachedAdaptiveInstance = new Holder<>(); |
| private volatile Class<?> cachedAdaptiveClass = null; |
| private String cachedDefaultName; |
| private volatile Throwable createAdaptiveInstanceError; |
| |
| private Set<Class<?>> cachedWrapperClasses; |
| |
| private Map<String, IllegalStateException> exceptions = new ConcurrentHashMap<>(); |
| |
| private static volatile LoadingStrategy[] strategies = loadLoadingStrategies(); |
| |
| public static void setLoadingStrategies(LoadingStrategy... strategies) { |
| if (ArrayUtils.isNotEmpty(strategies)) { |
| ExtensionLoader.strategies = strategies; |
| } |
| } |
| |
| /** |
| * Load all {@link Prioritized prioritized} {@link LoadingStrategy Loading Strategies} via {@link ServiceLoader} |
| * |
| * @return non-null |
| * @since 2.7.7 |
| */ |
| private static LoadingStrategy[] loadLoadingStrategies() { |
| return stream(load(LoadingStrategy.class).spliterator(), false) |
| .sorted() |
| .toArray(LoadingStrategy[]::new); |
| } |
| |
| /** |
| * Get all {@link LoadingStrategy Loading Strategies} |
| * |
| * @return non-null |
| * @see LoadingStrategy |
| * @see Prioritized |
| * @since 2.7.7 |
| */ |
| public static List<LoadingStrategy> getLoadingStrategies() { |
| return asList(strategies); |
| } |
| |
| private ExtensionLoader(Class<?> type) { |
| this.type = type; |
| objectFactory = (type == ExtensionFactory.class ? null : ExtensionLoader.getExtensionLoader(ExtensionFactory.class).getAdaptiveExtension()); |
| } |
| |
| private static <T> boolean withExtensionAnnotation(Class<T> type) { |
| return type.isAnnotationPresent(SPI.class); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public static <T> ExtensionLoader<T> getExtensionLoader(Class<T> type) { |
| if (type == null) { |
| throw new IllegalArgumentException("Extension type == null"); |
| } |
| if (!type.isInterface()) { |
| throw new IllegalArgumentException("Extension type (" + type + ") is not an interface!"); |
| } |
| if (!withExtensionAnnotation(type)) { |
| throw new IllegalArgumentException("Extension type (" + type + |
| ") is not an extension, because it is NOT annotated with @" + SPI.class.getSimpleName() + "!"); |
| } |
| |
| ExtensionLoader<T> loader = (ExtensionLoader<T>) EXTENSION_LOADERS.get(type); |
| if (loader == null) { |
| EXTENSION_LOADERS.putIfAbsent(type, new ExtensionLoader<T>(type)); |
| loader = (ExtensionLoader<T>) EXTENSION_LOADERS.get(type); |
| } |
| return loader; |
| } |
| |
| // For testing purposes only |
| public static void resetExtensionLoader(Class type) { |
| ExtensionLoader loader = EXTENSION_LOADERS.get(type); |
| if (loader != null) { |
| // Remove all instances associated with this loader as well |
| Map<String, Class<?>> classes = loader.getExtensionClasses(); |
| for (Map.Entry<String, Class<?>> entry : classes.entrySet()) { |
| EXTENSION_INSTANCES.remove(entry.getValue()); |
| } |
| classes.clear(); |
| EXTENSION_LOADERS.remove(type); |
| } |
| } |
| |
| public static void destroyAll() { |
| EXTENSION_INSTANCES.forEach((_type, instance) -> { |
| if (instance instanceof Lifecycle) { |
| Lifecycle lifecycle = (Lifecycle) instance; |
| try { |
| lifecycle.destroy(); |
| } catch (Exception e) { |
| logger.error("Error destroying extension " + lifecycle, e); |
| } |
| } |
| }); |
| } |
| |
| private static ClassLoader findClassLoader() { |
| return ClassUtils.getClassLoader(ExtensionLoader.class); |
| } |
| |
| public String getExtensionName(T extensionInstance) { |
| return getExtensionName(extensionInstance.getClass()); |
| } |
| |
| public String getExtensionName(Class<?> extensionClass) { |
| getExtensionClasses();// load class |
| return cachedNames.get(extensionClass); |
| } |
| |
| /** |
| * This is equivalent to {@code getActivateExtension(url, key, null)} |
| * |
| * @param url url |
| * @param key url parameter key which used to get extension point names |
| * @return extension list which are activated. |
| * @see #getActivateExtension(org.apache.dubbo.common.URL, String, String) |
| */ |
| public List<T> getActivateExtension(URL url, String key) { |
| return getActivateExtension(url, key, null); |
| } |
| |
| /** |
| * This is equivalent to {@code getActivateExtension(url, values, null)} |
| * |
| * @param url url |
| * @param values extension point names |
| * @return extension list which are activated |
| * @see #getActivateExtension(org.apache.dubbo.common.URL, String[], String) |
| */ |
| public List<T> getActivateExtension(URL url, String[] values) { |
| return getActivateExtension(url, values, null); |
| } |
| |
| /** |
| * This is equivalent to {@code getActivateExtension(url, url.getParameter(key).split(","), null)} |
| * |
| * @param url url |
| * @param key url parameter key which used to get extension point names |
| * @param group group |
| * @return extension list which are activated. |
| * @see #getActivateExtension(org.apache.dubbo.common.URL, String[], String) |
| */ |
| public List<T> getActivateExtension(URL url, String key, String group) { |
| String value = url.getParameter(key); |
| return getActivateExtension(url, StringUtils.isEmpty(value) ? null : COMMA_SPLIT_PATTERN.split(value), group); |
| } |
| |
| /** |
| * Get activate extensions. |
| * |
| * @param url url |
| * @param values extension point names |
| * @param group group |
| * @return extension list which are activated |
| * @see org.apache.dubbo.common.extension.Activate |
| */ |
| public List<T> getActivateExtension(URL url, String[] values, String group) { |
| List<T> activateExtensions = new ArrayList<>(); |
| List<String> names = values == null ? new ArrayList<>(0) : asList(values); |
| if (!names.contains(REMOVE_VALUE_PREFIX + DEFAULT_KEY)) { |
| getExtensionClasses(); |
| for (Map.Entry<String, Object> entry : cachedActivates.entrySet()) { |
| String name = entry.getKey(); |
| Object activate = entry.getValue(); |
| |
| String[] activateGroup, activateValue; |
| |
| if (activate instanceof Activate) { |
| activateGroup = ((Activate) activate).group(); |
| activateValue = ((Activate) activate).value(); |
| } else if (activate instanceof com.alibaba.dubbo.common.extension.Activate) { |
| activateGroup = ((com.alibaba.dubbo.common.extension.Activate) activate).group(); |
| activateValue = ((com.alibaba.dubbo.common.extension.Activate) activate).value(); |
| } else { |
| continue; |
| } |
| if (isMatchGroup(group, activateGroup) |
| && !names.contains(name) |
| && !names.contains(REMOVE_VALUE_PREFIX + name) |
| && isActive(activateValue, url)) { |
| activateExtensions.add(getExtension(name)); |
| } |
| } |
| activateExtensions.sort(ActivateComparator.COMPARATOR); |
| } |
| List<T> loadedExtensions = new ArrayList<>(); |
| for (int i = 0; i < names.size(); i++) { |
| String name = names.get(i); |
| if (!name.startsWith(REMOVE_VALUE_PREFIX) |
| && !names.contains(REMOVE_VALUE_PREFIX + name)) { |
| if (DEFAULT_KEY.equals(name)) { |
| if (!loadedExtensions.isEmpty()) { |
| activateExtensions.addAll(0, loadedExtensions); |
| loadedExtensions.clear(); |
| } |
| } else { |
| loadedExtensions.add(getExtension(name)); |
| } |
| } |
| } |
| if (!loadedExtensions.isEmpty()) { |
| activateExtensions.addAll(loadedExtensions); |
| } |
| return activateExtensions; |
| } |
| |
| private boolean isMatchGroup(String group, String[] groups) { |
| if (StringUtils.isEmpty(group)) { |
| return true; |
| } |
| if (groups != null && groups.length > 0) { |
| for (String g : groups) { |
| if (group.equals(g)) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| private boolean isActive(String[] keys, URL url) { |
| if (keys.length == 0) { |
| return true; |
| } |
| for (String key : keys) { |
| // @Active(value="key1:value1, key2:value2") |
| String keyValue = null; |
| if (key.contains(":")) { |
| String[] arr = key.split(":"); |
| key = arr[0]; |
| keyValue = arr[1]; |
| } |
| |
| for (Map.Entry<String, String> entry : url.getParameters().entrySet()) { |
| String k = entry.getKey(); |
| String v = entry.getValue(); |
| if ((k.equals(key) || k.endsWith("." + key)) |
| && ((keyValue != null && keyValue.equals(v)) || (keyValue == null && ConfigUtils.isNotEmpty(v)))) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Get extension's instance. Return <code>null</code> if extension is not found or is not initialized. Pls. note |
| * that this method will not trigger extension load. |
| * <p> |
| * In order to trigger extension load, call {@link #getExtension(String)} instead. |
| * |
| * @see #getExtension(String) |
| */ |
| @SuppressWarnings("unchecked") |
| public T getLoadedExtension(String name) { |
| if (StringUtils.isEmpty(name)) { |
| throw new IllegalArgumentException("Extension name == null"); |
| } |
| Holder<Object> holder = getOrCreateHolder(name); |
| return (T) holder.get(); |
| } |
| |
| private Holder<Object> getOrCreateHolder(String name) { |
| Holder<Object> holder = cachedInstances.get(name); |
| if (holder == null) { |
| cachedInstances.putIfAbsent(name, new Holder<>()); |
| holder = cachedInstances.get(name); |
| } |
| return holder; |
| } |
| |
| /** |
| * Return the list of extensions which are already loaded. |
| * <p> |
| * Usually {@link #getSupportedExtensions()} should be called in order to get all extensions. |
| * |
| * @see #getSupportedExtensions() |
| */ |
| public Set<String> getLoadedExtensions() { |
| return Collections.unmodifiableSet(new TreeSet<>(cachedInstances.keySet())); |
| } |
| |
| public List<T> getLoadedExtensionInstances() { |
| List<T> instances = new ArrayList<>(); |
| cachedInstances.values().forEach(holder -> instances.add((T) holder.get())); |
| return instances; |
| } |
| |
| public Object getLoadedAdaptiveExtensionInstances() { |
| return cachedAdaptiveInstance.get(); |
| } |
| |
| // public T getPrioritizedExtensionInstance() { |
| // Set<String> supported = getSupportedExtensions(); |
| // |
| // Set<T> instances = new HashSet<>(); |
| // Set<T> prioritized = new HashSet<>(); |
| // for (String s : supported) { |
| // |
| // } |
| // |
| // } |
| |
| /** |
| * Find the extension with the given name. If the specified name is not found, then {@link IllegalStateException} |
| * will be thrown. |
| */ |
| @SuppressWarnings("unchecked") |
| public T getExtension(String name) { |
| return getExtension(name, true); |
| } |
| |
| public T getExtension(String name, boolean wrap) { |
| if (StringUtils.isEmpty(name)) { |
| throw new IllegalArgumentException("Extension name == null"); |
| } |
| if ("true".equals(name)) { |
| return getDefaultExtension(); |
| } |
| final Holder<Object> holder = getOrCreateHolder(name); |
| Object instance = holder.get(); |
| if (instance == null) { |
| synchronized (holder) { |
| instance = holder.get(); |
| if (instance == null) { |
| instance = createExtension(name, wrap); |
| holder.set(instance); |
| } |
| } |
| } |
| return (T) instance; |
| } |
| |
| /** |
| * Get the extension by specified name if found, or {@link #getDefaultExtension() returns the default one} |
| * |
| * @param name the name of extension |
| * @return non-null |
| */ |
| public T getOrDefaultExtension(String name) { |
| return containsExtension(name) ? getExtension(name) : getDefaultExtension(); |
| } |
| |
| /** |
| * Return default extension, return <code>null</code> if it's not configured. |
| */ |
| public T getDefaultExtension() { |
| getExtensionClasses(); |
| if (StringUtils.isBlank(cachedDefaultName) || "true".equals(cachedDefaultName)) { |
| return null; |
| } |
| return getExtension(cachedDefaultName); |
| } |
| |
| public boolean hasExtension(String name) { |
| if (StringUtils.isEmpty(name)) { |
| throw new IllegalArgumentException("Extension name == null"); |
| } |
| Class<?> c = this.getExtensionClass(name); |
| return c != null; |
| } |
| |
| public Set<String> getSupportedExtensions() { |
| Map<String, Class<?>> clazzes = getExtensionClasses(); |
| return Collections.unmodifiableSet(new TreeSet<>(clazzes.keySet())); |
| } |
| |
| public Set<T> getSupportedExtensionInstances() { |
| List<T> instances = new LinkedList<>(); |
| Set<String> supportedExtensions = getSupportedExtensions(); |
| if (CollectionUtils.isNotEmpty(supportedExtensions)) { |
| for (String name : supportedExtensions) { |
| instances.add(getExtension(name)); |
| } |
| } |
| // sort the Prioritized instances |
| sort(instances, Prioritized.COMPARATOR); |
| return new LinkedHashSet<>(instances); |
| } |
| |
| /** |
| * Return default extension name, return <code>null</code> if not configured. |
| */ |
| public String getDefaultExtensionName() { |
| getExtensionClasses(); |
| return cachedDefaultName; |
| } |
| |
| /** |
| * Register new extension via API |
| * |
| * @param name extension name |
| * @param clazz extension class |
| * @throws IllegalStateException when extension with the same name has already been registered. |
| */ |
| public void addExtension(String name, Class<?> clazz) { |
| getExtensionClasses(); // load classes |
| |
| if (!type.isAssignableFrom(clazz)) { |
| throw new IllegalStateException("Input type " + |
| clazz + " doesn't implement the Extension " + type); |
| } |
| if (clazz.isInterface()) { |
| throw new IllegalStateException("Input type " + |
| clazz + " can't be interface!"); |
| } |
| |
| if (!clazz.isAnnotationPresent(Adaptive.class)) { |
| if (StringUtils.isBlank(name)) { |
| throw new IllegalStateException("Extension name is blank (Extension " + type + ")!"); |
| } |
| if (cachedClasses.get().containsKey(name)) { |
| throw new IllegalStateException("Extension name " + |
| name + " already exists (Extension " + type + ")!"); |
| } |
| |
| cachedNames.put(clazz, name); |
| cachedClasses.get().put(name, clazz); |
| } else { |
| if (cachedAdaptiveClass != null) { |
| throw new IllegalStateException("Adaptive Extension already exists (Extension " + type + ")!"); |
| } |
| |
| cachedAdaptiveClass = clazz; |
| } |
| } |
| |
| /** |
| * Replace the existing extension via API |
| * |
| * @param name extension name |
| * @param clazz extension class |
| * @throws IllegalStateException when extension to be placed doesn't exist |
| * @deprecated not recommended any longer, and use only when test |
| */ |
| @Deprecated |
| public void replaceExtension(String name, Class<?> clazz) { |
| getExtensionClasses(); // load classes |
| |
| if (!type.isAssignableFrom(clazz)) { |
| throw new IllegalStateException("Input type " + |
| clazz + " doesn't implement Extension " + type); |
| } |
| if (clazz.isInterface()) { |
| throw new IllegalStateException("Input type " + |
| clazz + " can't be interface!"); |
| } |
| |
| if (!clazz.isAnnotationPresent(Adaptive.class)) { |
| if (StringUtils.isBlank(name)) { |
| throw new IllegalStateException("Extension name is blank (Extension " + type + ")!"); |
| } |
| if (!cachedClasses.get().containsKey(name)) { |
| throw new IllegalStateException("Extension name " + |
| name + " doesn't exist (Extension " + type + ")!"); |
| } |
| |
| cachedNames.put(clazz, name); |
| cachedClasses.get().put(name, clazz); |
| cachedInstances.remove(name); |
| } else { |
| if (cachedAdaptiveClass == null) { |
| throw new IllegalStateException("Adaptive Extension doesn't exist (Extension " + type + ")!"); |
| } |
| |
| cachedAdaptiveClass = clazz; |
| cachedAdaptiveInstance.set(null); |
| } |
| } |
| |
| @SuppressWarnings("unchecked") |
| public T getAdaptiveExtension() { |
| Object instance = cachedAdaptiveInstance.get(); |
| if (instance == null) { |
| if (createAdaptiveInstanceError != null) { |
| throw new IllegalStateException("Failed to create adaptive instance: " + |
| createAdaptiveInstanceError.toString(), |
| createAdaptiveInstanceError); |
| } |
| |
| synchronized (cachedAdaptiveInstance) { |
| instance = cachedAdaptiveInstance.get(); |
| if (instance == null) { |
| try { |
| instance = createAdaptiveExtension(); |
| cachedAdaptiveInstance.set(instance); |
| } catch (Throwable t) { |
| createAdaptiveInstanceError = t; |
| throw new IllegalStateException("Failed to create adaptive instance: " + t.toString(), t); |
| } |
| } |
| } |
| } |
| |
| return (T) instance; |
| } |
| |
| private IllegalStateException findException(String name) { |
| StringBuilder buf = new StringBuilder("No such extension " + type.getName() + " by name " + name); |
| |
| int i = 1; |
| for (Map.Entry<String, IllegalStateException> entry : exceptions.entrySet()) { |
| if (entry.getKey().toLowerCase().startsWith(name.toLowerCase())) { |
| if (i == 1) { |
| buf.append(", possible causes: "); |
| } |
| buf.append("\r\n("); |
| buf.append(i++); |
| buf.append(") "); |
| buf.append(entry.getKey()); |
| buf.append(":\r\n"); |
| buf.append(StringUtils.toString(entry.getValue())); |
| } |
| } |
| |
| if (i == 1) { |
| buf.append(", no related exception was found, please check whether related SPI module is missing."); |
| } |
| return new IllegalStateException(buf.toString()); |
| } |
| |
| @SuppressWarnings("unchecked") |
| private T createExtension(String name, boolean wrap) { |
| Class<?> clazz = getExtensionClasses().get(name); |
| if (clazz == null) { |
| throw findException(name); |
| } |
| try { |
| T instance = (T) EXTENSION_INSTANCES.get(clazz); |
| if (instance == null) { |
| EXTENSION_INSTANCES.putIfAbsent(clazz, clazz.newInstance()); |
| instance = (T) EXTENSION_INSTANCES.get(clazz); |
| } |
| injectExtension(instance); |
| |
| |
| if (wrap) { |
| |
| List<Class<?>> wrapperClassesList = new ArrayList<>(); |
| if (cachedWrapperClasses != null) { |
| wrapperClassesList.addAll(cachedWrapperClasses); |
| wrapperClassesList.sort(WrapperComparator.COMPARATOR); |
| Collections.reverse(wrapperClassesList); |
| } |
| |
| if (CollectionUtils.isNotEmpty(wrapperClassesList)) { |
| for (Class<?> wrapperClass : wrapperClassesList) { |
| Wrapper wrapper = wrapperClass.getAnnotation(Wrapper.class); |
| if (wrapper == null |
| || (ArrayUtils.contains(wrapper.matches(), name) && !ArrayUtils.contains(wrapper.mismatches(), name))) { |
| instance = injectExtension((T) wrapperClass.getConstructor(type).newInstance(instance)); |
| } |
| } |
| } |
| } |
| |
| initExtension(instance); |
| return instance; |
| } catch (Throwable t) { |
| throw new IllegalStateException("Extension instance (name: " + name + ", class: " + |
| type + ") couldn't be instantiated: " + t.getMessage(), t); |
| } |
| } |
| |
| private boolean containsExtension(String name) { |
| return getExtensionClasses().containsKey(name); |
| } |
| |
| private T injectExtension(T instance) { |
| |
| if (objectFactory == null) { |
| return instance; |
| } |
| |
| try { |
| for (Method method : instance.getClass().getMethods()) { |
| if (!isSetter(method)) { |
| continue; |
| } |
| /** |
| * Check {@link DisableInject} to see if we need auto injection for this property |
| */ |
| if (method.getAnnotation(DisableInject.class) != null) { |
| continue; |
| } |
| Class<?> pt = method.getParameterTypes()[0]; |
| if (ReflectUtils.isPrimitives(pt)) { |
| continue; |
| } |
| |
| try { |
| String property = getSetterProperty(method); |
| Object object = objectFactory.getExtension(pt, property); |
| if (object != null) { |
| method.invoke(instance, object); |
| } |
| } catch (Exception e) { |
| logger.error("Failed to inject via method " + method.getName() |
| + " of interface " + type.getName() + ": " + e.getMessage(), e); |
| } |
| |
| } |
| } catch (Exception e) { |
| logger.error(e.getMessage(), e); |
| } |
| return instance; |
| } |
| |
| private void initExtension(T instance) { |
| if (instance instanceof Lifecycle) { |
| Lifecycle lifecycle = (Lifecycle) instance; |
| lifecycle.initialize(); |
| } |
| } |
| |
| /** |
| * get properties name for setter, for instance: setVersion, return "version" |
| * <p> |
| * return "", if setter name with length less than 3 |
| */ |
| private String getSetterProperty(Method method) { |
| return method.getName().length() > 3 ? method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4) : ""; |
| } |
| |
| /** |
| * return true if and only if: |
| * <p> |
| * 1, public |
| * <p> |
| * 2, name starts with "set" |
| * <p> |
| * 3, only has one parameter |
| */ |
| private boolean isSetter(Method method) { |
| return method.getName().startsWith("set") |
| && method.getParameterTypes().length == 1 |
| && Modifier.isPublic(method.getModifiers()); |
| } |
| |
| private Class<?> getExtensionClass(String name) { |
| if (type == null) { |
| throw new IllegalArgumentException("Extension type == null"); |
| } |
| if (name == null) { |
| throw new IllegalArgumentException("Extension name == null"); |
| } |
| return getExtensionClasses().get(name); |
| } |
| |
| private Map<String, Class<?>> getExtensionClasses() { |
| Map<String, Class<?>> classes = cachedClasses.get(); |
| if (classes == null) { |
| synchronized (cachedClasses) { |
| classes = cachedClasses.get(); |
| if (classes == null) { |
| classes = loadExtensionClasses(); |
| cachedClasses.set(classes); |
| } |
| } |
| } |
| return classes; |
| } |
| |
| /** |
| * synchronized in getExtensionClasses |
| */ |
| private Map<String, Class<?>> loadExtensionClasses() { |
| cacheDefaultExtensionName(); |
| |
| Map<String, Class<?>> extensionClasses = new HashMap<>(); |
| |
| for (LoadingStrategy strategy : strategies) { |
| loadDirectory(extensionClasses, strategy.directory(), type.getName(), strategy.preferExtensionClassLoader(), strategy.overridden(), strategy.excludedPackages()); |
| loadDirectory(extensionClasses, strategy.directory(), type.getName().replace("org.apache", "com.alibaba"), strategy.preferExtensionClassLoader(), strategy.overridden(), strategy.excludedPackages()); |
| } |
| |
| return extensionClasses; |
| } |
| |
| /** |
| * extract and cache default extension name if exists |
| */ |
| private void cacheDefaultExtensionName() { |
| final SPI defaultAnnotation = type.getAnnotation(SPI.class); |
| if (defaultAnnotation == null) { |
| return; |
| } |
| |
| String value = defaultAnnotation.value(); |
| if ((value = value.trim()).length() > 0) { |
| String[] names = NAME_SEPARATOR.split(value); |
| if (names.length > 1) { |
| throw new IllegalStateException("More than 1 default extension name on extension " + type.getName() |
| + ": " + Arrays.toString(names)); |
| } |
| if (names.length == 1) { |
| cachedDefaultName = names[0]; |
| } |
| } |
| } |
| |
| private void loadDirectory(Map<String, Class<?>> extensionClasses, String dir, String type) { |
| loadDirectory(extensionClasses, dir, type, false, false); |
| } |
| |
| private void loadDirectory(Map<String, Class<?>> extensionClasses, String dir, String type, |
| boolean extensionLoaderClassLoaderFirst, boolean overridden, String... excludedPackages) { |
| String fileName = dir + type; |
| try { |
| Enumeration<java.net.URL> urls = null; |
| ClassLoader classLoader = findClassLoader(); |
| |
| // try to load from ExtensionLoader's ClassLoader first |
| if (extensionLoaderClassLoaderFirst) { |
| ClassLoader extensionLoaderClassLoader = ExtensionLoader.class.getClassLoader(); |
| if (ClassLoader.getSystemClassLoader() != extensionLoaderClassLoader) { |
| urls = extensionLoaderClassLoader.getResources(fileName); |
| } |
| } |
| |
| if (urls == null || !urls.hasMoreElements()) { |
| if (classLoader != null) { |
| urls = classLoader.getResources(fileName); |
| } else { |
| urls = ClassLoader.getSystemResources(fileName); |
| } |
| } |
| |
| if (urls != null) { |
| while (urls.hasMoreElements()) { |
| java.net.URL resourceURL = urls.nextElement(); |
| loadResource(extensionClasses, classLoader, resourceURL, overridden, excludedPackages); |
| } |
| } |
| } catch (Throwable t) { |
| logger.error("Exception occurred when loading extension class (interface: " + |
| type + ", description file: " + fileName + ").", t); |
| } |
| } |
| |
| private void loadResource(Map<String, Class<?>> extensionClasses, ClassLoader classLoader, |
| java.net.URL resourceURL, boolean overridden, String... excludedPackages) { |
| try { |
| try (BufferedReader reader = new BufferedReader(new InputStreamReader(resourceURL.openStream(), StandardCharsets.UTF_8))) { |
| String line; |
| String clazz = null; |
| while ((line = reader.readLine()) != null) { |
| final int ci = line.indexOf('#'); |
| if (ci >= 0) { |
| line = line.substring(0, ci); |
| } |
| line = line.trim(); |
| if (line.length() > 0) { |
| try { |
| String name = null; |
| int i = line.indexOf('='); |
| if (i > 0) { |
| name = line.substring(0, i).trim(); |
| clazz = line.substring(i + 1).trim(); |
| } else { |
| clazz = line; |
| } |
| if (StringUtils.isNotEmpty(clazz) && !isExcluded(clazz, excludedPackages)) { |
| loadClass(extensionClasses, resourceURL, Class.forName(clazz, true, classLoader), name, overridden); |
| } |
| } catch (Throwable t) { |
| IllegalStateException e = new IllegalStateException("Failed to load extension class (interface: " + type + ", class line: " + line + ") in " + resourceURL + ", cause: " + t.getMessage(), t); |
| exceptions.put(line, e); |
| } |
| } |
| } |
| } |
| } catch (Throwable t) { |
| logger.error("Exception occurred when loading extension class (interface: " + |
| type + ", class file: " + resourceURL + ") in " + resourceURL, t); |
| } |
| } |
| |
| private boolean isExcluded(String className, String... excludedPackages) { |
| if (excludedPackages != null) { |
| for (String excludePackage : excludedPackages) { |
| if (className.startsWith(excludePackage + ".")) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| private void loadClass(Map<String, Class<?>> extensionClasses, java.net.URL resourceURL, Class<?> clazz, String name, |
| boolean overridden) throws NoSuchMethodException { |
| if (!type.isAssignableFrom(clazz)) { |
| throw new IllegalStateException("Error occurred when loading extension class (interface: " + |
| type + ", class line: " + clazz.getName() + "), class " |
| + clazz.getName() + " is not subtype of interface."); |
| } |
| if (clazz.isAnnotationPresent(Adaptive.class)) { |
| cacheAdaptiveClass(clazz, overridden); |
| } else if (isWrapperClass(clazz)) { |
| cacheWrapperClass(clazz); |
| } else { |
| clazz.getConstructor(); |
| if (StringUtils.isEmpty(name)) { |
| name = findAnnotationName(clazz); |
| if (name.length() == 0) { |
| throw new IllegalStateException("No such extension name for the class " + clazz.getName() + " in the config " + resourceURL); |
| } |
| } |
| |
| String[] names = NAME_SEPARATOR.split(name); |
| if (ArrayUtils.isNotEmpty(names)) { |
| cacheActivateClass(clazz, names[0]); |
| for (String n : names) { |
| cacheName(clazz, n); |
| saveInExtensionClass(extensionClasses, clazz, n, overridden); |
| } |
| } |
| } |
| } |
| |
| /** |
| * cache name |
| */ |
| private void cacheName(Class<?> clazz, String name) { |
| if (!cachedNames.containsKey(clazz)) { |
| cachedNames.put(clazz, name); |
| } |
| } |
| |
| /** |
| * put clazz in extensionClasses |
| */ |
| private void saveInExtensionClass(Map<String, Class<?>> extensionClasses, Class<?> clazz, String name, boolean overridden) { |
| Class<?> c = extensionClasses.get(name); |
| if (c == null || overridden) { |
| extensionClasses.put(name, clazz); |
| } else if (c != clazz) { |
| String duplicateMsg = "Duplicate extension " + type.getName() + " name " + name + " on " + c.getName() + " and " + clazz.getName(); |
| logger.error(duplicateMsg); |
| throw new IllegalStateException(duplicateMsg); |
| } |
| } |
| |
| /** |
| * cache Activate class which is annotated with <code>Activate</code> |
| * <p> |
| * for compatibility, also cache class with old alibaba Activate annotation |
| */ |
| private void cacheActivateClass(Class<?> clazz, String name) { |
| Activate activate = clazz.getAnnotation(Activate.class); |
| if (activate != null) { |
| cachedActivates.put(name, activate); |
| } else { |
| // support com.alibaba.dubbo.common.extension.Activate |
| com.alibaba.dubbo.common.extension.Activate oldActivate = clazz.getAnnotation(com.alibaba.dubbo.common.extension.Activate.class); |
| if (oldActivate != null) { |
| cachedActivates.put(name, oldActivate); |
| } |
| } |
| } |
| |
| /** |
| * cache Adaptive class which is annotated with <code>Adaptive</code> |
| */ |
| private void cacheAdaptiveClass(Class<?> clazz, boolean overridden) { |
| if (cachedAdaptiveClass == null || overridden) { |
| cachedAdaptiveClass = clazz; |
| } else if (!cachedAdaptiveClass.equals(clazz)) { |
| throw new IllegalStateException("More than 1 adaptive class found: " |
| + cachedAdaptiveClass.getName() |
| + ", " + clazz.getName()); |
| } |
| } |
| |
| /** |
| * cache wrapper class |
| * <p> |
| * like: ProtocolFilterWrapper, ProtocolListenerWrapper |
| */ |
| private void cacheWrapperClass(Class<?> clazz) { |
| if (cachedWrapperClasses == null) { |
| cachedWrapperClasses = new ConcurrentHashSet<>(); |
| } |
| cachedWrapperClasses.add(clazz); |
| } |
| |
| /** |
| * test if clazz is a wrapper class |
| * <p> |
| * which has Constructor with given class type as its only argument |
| */ |
| private boolean isWrapperClass(Class<?> clazz) { |
| try { |
| clazz.getConstructor(type); |
| return true; |
| } catch (NoSuchMethodException e) { |
| return false; |
| } |
| } |
| |
| @SuppressWarnings("deprecation") |
| private String findAnnotationName(Class<?> clazz) { |
| org.apache.dubbo.common.Extension extension = clazz.getAnnotation(org.apache.dubbo.common.Extension.class); |
| if (extension != null) { |
| return extension.value(); |
| } |
| |
| String name = clazz.getSimpleName(); |
| if (name.endsWith(type.getSimpleName())) { |
| name = name.substring(0, name.length() - type.getSimpleName().length()); |
| } |
| return name.toLowerCase(); |
| } |
| |
| @SuppressWarnings("unchecked") |
| private T createAdaptiveExtension() { |
| try { |
| return injectExtension((T) getAdaptiveExtensionClass().newInstance()); |
| } catch (Exception e) { |
| throw new IllegalStateException("Can't create adaptive extension " + type + ", cause: " + e.getMessage(), e); |
| } |
| } |
| |
| private Class<?> getAdaptiveExtensionClass() { |
| getExtensionClasses(); |
| if (cachedAdaptiveClass != null) { |
| return cachedAdaptiveClass; |
| } |
| return cachedAdaptiveClass = createAdaptiveExtensionClass(); |
| } |
| |
| private Class<?> createAdaptiveExtensionClass() { |
| String code = new AdaptiveClassCodeGenerator(type, cachedDefaultName).generate(); |
| ClassLoader classLoader = findClassLoader(); |
| org.apache.dubbo.common.compiler.Compiler compiler = ExtensionLoader.getExtensionLoader(org.apache.dubbo.common.compiler.Compiler.class).getAdaptiveExtension(); |
| return compiler.compile(code, classLoader); |
| } |
| |
| @Override |
| public String toString() { |
| return this.getClass().getName() + "[" + type.getName() + "]"; |
| } |
| |
| } |