/* | |
* 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.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 (isMatch(key, keyValue, k, v)) { | |
return true; | |
} | |
} | |
for (Map.Entry<String, Map<String, String>> entry : url.getMethodParameters().entrySet()) { | |
Map<String, String> methodKeyValues = entry.getValue(); | |
for (Map.Entry<String, String> methodEntry : methodKeyValues.entrySet()) { | |
String k = methodEntry.getKey(); | |
String v = methodEntry.getValue(); | |
return isMatch(key, keyValue, k, v); | |
} | |
} | |
} | |
return false; | |
} | |
private boolean isMatch(String key, String value, String k, String v) { | |
return k.equals(key) && ((value != null && value.equals(v)) || (value == null && ConfigUtils.isNotEmpty(v))); | |
} | |
/** | |
* 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) { | |
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); | |
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) { | |
for (Map.Entry<String, IllegalStateException> entry : exceptions.entrySet()) { | |
if (entry.getKey().toLowerCase().contains(name.toLowerCase())) { | |
return entry.getValue(); | |
} | |
} | |
StringBuilder buf = new StringBuilder("No such extension " + type.getName() + " by name " + name); | |
int i = 1; | |
for (Map.Entry<String, IllegalStateException> entry : exceptions.entrySet()) { | |
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())); | |
} | |
return new IllegalStateException(buf.toString()); | |
} | |
@SuppressWarnings("unchecked") | |
private T createExtension(String name) { | |
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); | |
Set<Class<?>> wrapperClasses = cachedWrapperClasses; | |
if (CollectionUtils.isNotEmpty(wrapperClasses)) { | |
for (Class<?> wrapperClass : wrapperClasses) { | |
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; | |
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(); | |
line = line.substring(i + 1).trim(); | |
} | |
if (line.length() > 0 && !isExcluded(line, excludedPackages)) { | |
loadClass(extensionClasses, resourceURL, Class.forName(line, 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() + "]"; | |
} | |
} |