/* * Copyright 1999-2011 Alibaba Group. * * Licensed 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 com.alibaba.dubbo.common.extension; import java.io.BufferedReader; import java.io.InputStreamReader; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Enumeration; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import java.util.TreeSet; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import java.util.regex.Pattern; import com.alibaba.dubbo.common.Constants; import com.alibaba.dubbo.common.URL; import com.alibaba.dubbo.common.extension.support.ActivateComparator; import com.alibaba.dubbo.common.logger.Logger; import com.alibaba.dubbo.common.logger.LoggerFactory; import com.alibaba.dubbo.common.utils.ConcurrentHashSet; import com.alibaba.dubbo.common.utils.ConfigUtils; import com.alibaba.dubbo.common.utils.Holder; import com.alibaba.dubbo.common.utils.StringUtils; /** * Dubbo使用的扩展点获取。<p> * <ul> * <li>自动注入关联扩展点。</li> * <li>自动Wrap上扩展点的Wrap类。</li> * <li>缺省获得的的扩展点是一个Adaptive Instance。 * </ul> * * @see <a href="http://java.sun.com/j2se/1.5.0/docs/guide/jar/jar.html#Service%20Provider">JDK5.0的自动发现机制实现</a> * * @author william.liangf * @author ding.lid * * @see com.alibaba.dubbo.common.extension.SPI * @see com.alibaba.dubbo.common.extension.Adaptive * @see com.alibaba.dubbo.common.extension.Activate */ public class ExtensionLoader<T> { private static final Logger logger = LoggerFactory.getLogger(ExtensionLoader.class); private static final String SERVICES_DIRECTORY = "META-INF/services/"; private static final String DUBBO_DIRECTORY = "META-INF/dubbo/"; private static final String DUBBO_INTERNAL_DIRECTORY = DUBBO_DIRECTORY + "internal/"; private static final Pattern NAME_SEPARATOR = Pattern.compile("\\s*[,]+\\s*"); private static final ConcurrentMap<Class<?>, ExtensionLoader<?>> EXTENSION_LOADERS = new ConcurrentHashMap<Class<?>, ExtensionLoader<?>>(); private static final ConcurrentMap<Class<?>, Object> EXTENSION_INSTANCES = new ConcurrentHashMap<Class<?>, Object>(); // ============================== private final Class<?> type; private final ExtensionFactory objectFactory; private final ConcurrentMap<Class<?>, String> cachedNames = new ConcurrentHashMap<Class<?>, String>(); private final Holder<Map<String, Class<?>>> cachedClasses = new Holder<Map<String,Class<?>>>(); private final Map<String, Activate> cachedActivates = new ConcurrentHashMap<String, Activate>(); private volatile Class<?> cachedAdaptiveClass = null; private final ConcurrentMap<String, Holder<Object>> cachedInstances = new ConcurrentHashMap<String, Holder<Object>>(); private String cachedDefaultName; private final Holder<Object> cachedAdaptiveInstance = new Holder<Object>(); private volatile Throwable createAdaptiveInstanceError; private Set<Class<?>> cachedWrapperClasses; private Map<String, IllegalStateException> exceptions = new ConcurrentHashMap<String, IllegalStateException>(); 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 interface!"); } if(!withExtensionAnnotation(type)) { throw new IllegalArgumentException("Extension type(" + type + ") is not extension, because WITHOUT @" + SPI.class.getSimpleName() + " Annotation!"); } 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; } private ExtensionLoader(Class<?> type) { this.type = type; objectFactory = (type == ExtensionFactory.class ? null : ExtensionLoader.getExtensionLoader(ExtensionFactory.class).getAdaptiveExtension()); } public String getExtensionName(T extensionInstance) { return getExtensionName(extensionInstance.getClass()); } public String getExtensionName(Class<?> extensionClass) { return cachedNames.get(extensionClass); } /** * This is equivalent to <pre> * getActivateExtension(url, key, null); * </pre> * * @param url url * @param key url parameter key which used to get extension point names * @return extension list which are activated. * @see #getActivateExtension(com.alibaba.dubbo.common.URL, String, String) */ public List<T> getActivateExtension(URL url, String key) { return getActivateExtension(url, key, null); } /** * This is equivalent to <pre> * getActivateExtension(url, values, null); * </pre> * * @see #getActivateExtension(com.alibaba.dubbo.common.URL, String[], String) * @param url url * @param values extension point names * @return extension list which are activated */ public List<T> getActivateExtension(URL url, String[] values) { return getActivateExtension(url, values, null); } /** * This is equivalent to <pre> * getActivateExtension(url, url.getParameter(key).split(","), null); * </pre> * * @see #getActivateExtension(com.alibaba.dubbo.common.URL, String[], String) * @param url url * @param key url parameter key which used to get extension point names * @param group group * @return extension list which are activated. */ public List<T> getActivateExtension(URL url, String key, String group) { String value = url.getParameter(key); return getActivateExtension(url, value == null || value.length() == 0 ? null : Constants.COMMA_SPLIT_PATTERN.split(value), group); } /** * Get activate extensions. * * @see com.alibaba.dubbo.common.extension.Activate * @param url url * @param values extension point names * @param group group * @return extension list which are activated */ public List<T> getActivateExtension(URL url, String[] values, String group) { List<T> exts = new ArrayList<T>(); List<String> names = values == null ? new ArrayList<String>(0) : Arrays.asList(values); if (! names.contains(Constants.REMOVE_VALUE_PREFIX + Constants.DEFAULT_KEY)) { getExtensionClasses(); for (Map.Entry<String, Activate> entry : cachedActivates.entrySet()) { String name = entry.getKey(); Activate activate = entry.getValue(); if (isMatchGroup(group, activate.group())) { T ext = getExtension(name); if (! names.contains(name) && ! names.contains(Constants.REMOVE_VALUE_PREFIX + name) && isActive(activate, url)) { exts.add(ext); } } } Collections.sort(exts, ActivateComparator.COMPARATOR); } List<T> usrs = new ArrayList<T>(); for (int i = 0; i < names.size(); i ++) { String name = names.get(i); if (! name.startsWith(Constants.REMOVE_VALUE_PREFIX) && ! names.contains(Constants.REMOVE_VALUE_PREFIX + name)) { if (Constants.DEFAULT_KEY.equals(name)) { if (usrs.size() > 0) { exts.addAll(0, usrs); usrs.clear(); } } else { T ext = getExtension(name); usrs.add(ext); } } } if (usrs.size() > 0) { exts.addAll(usrs); } return exts; } private boolean isMatchGroup(String group, String[] groups) { if (group == null || group.length() == 0) { return true; } if (groups != null && groups.length > 0) { for (String g : groups) { if (group.equals(g)) { return true; } } } return false; } private boolean isActive(Activate activate, URL url) { String[] keys = activate.value(); if (keys == null || keys.length == 0) { return true; } for (String key : keys) { for (Map.Entry<String, String> entry : url.getParameters().entrySet()) { String k = entry.getKey(); String v = entry.getValue(); if ((k.equals(key) || k.endsWith("." + key)) && ConfigUtils.isNotEmpty(v)) { return true; } } } return false; } /** * 返回扩展点实例,如果没有指定的扩展点或是还没加载(即实例化)则返回<code>null</code>。注意:此方法不会触发扩展点的加载。 * <p /> * 一般应该调用{@link #getExtension(String)}方法获得扩展,这个方法会触发扩展点加载。 * * @see #getExtension(String) */ @SuppressWarnings("unchecked") public T getLoadedExtension(String name) { if (name == null || name.length() == 0) throw new IllegalArgumentException("Extension name == null"); Holder<Object> holder = cachedInstances.get(name); if (holder == null) { cachedInstances.putIfAbsent(name, new Holder<Object>()); holder = cachedInstances.get(name); } return (T) holder.get(); } /** * 返回已经加载的扩展点的名字。 * <p /> * 一般应该调用{@link #getSupportedExtensions()}方法获得扩展,这个方法会返回所有的扩展点。 * * @see #getSupportedExtensions() */ public Set<String> getLoadedExtensions() { return Collections.unmodifiableSet(new TreeSet<String>(cachedInstances.keySet())); } /** * 返回指定名字的扩展。如果指定名字的扩展不存在,则抛异常 {@link IllegalStateException}. * * @param name * @return */ @SuppressWarnings("unchecked") public T getExtension(String name) { if (name == null || name.length() == 0) throw new IllegalArgumentException("Extension name == null"); if ("true".equals(name)) { return getDefaultExtension(); } Holder<Object> holder = cachedInstances.get(name); if (holder == null) { cachedInstances.putIfAbsent(name, new Holder<Object>()); holder = cachedInstances.get(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; } /** * 返回缺省的扩展,如果没有设置则返回<code>null</code>。 */ public T getDefaultExtension() { getExtensionClasses(); if(null == cachedDefaultName || cachedDefaultName.length() == 0 || "true".equals(cachedDefaultName)) { return null; } return getExtension(cachedDefaultName); } public boolean hasExtension(String name) { if (name == null || name.length() == 0) throw new IllegalArgumentException("Extension name == null"); try { return getExtensionClass(name) != null; } catch (Throwable t) { return false; } } public Set<String> getSupportedExtensions() { Map<String, Class<?>> clazzes = getExtensionClasses(); return Collections.unmodifiableSet(new TreeSet<String>(clazzes.keySet())); } /** * 返回缺省的扩展点名,如果没有设置缺省则返回<code>null</code>。 */ public String getDefaultExtensionName() { getExtensionClasses(); return cachedDefaultName; } /** * 编程方式添加新扩展点。 * * @param name 扩展点名 * @param clazz 扩展点类 * @throws IllegalStateException 要添加扩展点名已经存在。 */ public void addExtension(String name, Class<?> clazz) { getExtensionClasses(); // load classes if(!type.isAssignableFrom(clazz)) { throw new IllegalStateException("Input type " + clazz + "not implement Extension " + type); } if(clazz.isInterface()) { throw new IllegalStateException("Input type " + clazz + "can not 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 existed(Extension " + type + ")!"); } cachedNames.put(clazz, name); cachedClasses.get().put(name, clazz); } else { if(cachedAdaptiveClass != null) { throw new IllegalStateException("Adaptive Extension already existed(Extension " + type + ")!"); } cachedAdaptiveClass = clazz; } } /** * 编程方式添加替换已有扩展点。 * * @param name 扩展点名 * @param clazz 扩展点类 * @throws IllegalStateException 要添加扩展点名已经存在。 * @deprecated 不推荐应用使用,一般只在测试时可以使用 */ @Deprecated public void replaceExtension(String name, Class<?> clazz) { getExtensionClasses(); // load classes if(!type.isAssignableFrom(clazz)) { throw new IllegalStateException("Input type " + clazz + "not implement Extension " + type); } if(clazz.isInterface()) { throw new IllegalStateException("Input type " + clazz + "can not 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 + " not existed(Extension " + type + ")!"); } cachedNames.put(clazz, name); cachedClasses.get().put(name, clazz); cachedInstances.remove(name); } else { if(cachedAdaptiveClass == null) { throw new IllegalStateException("Adaptive Extension not existed(Extension " + type + ")!"); } cachedAdaptiveClass = clazz; cachedAdaptiveInstance.set(null); } } @SuppressWarnings("unchecked") public T getAdaptiveExtension() { Object instance = cachedAdaptiveInstance.get(); if (instance == null) { if(createAdaptiveInstanceError == null) { synchronized (cachedAdaptiveInstance) { instance = cachedAdaptiveInstance.get(); if (instance == null) { try { instance = createAdaptiveExtension(); cachedAdaptiveInstance.set(instance); } catch (Throwable t) { createAdaptiveInstanceError = t; throw new IllegalStateException("fail to create adaptive instance: " + t.toString(), t); } } } } else { throw new IllegalStateException("fail to create adaptive instance: " + createAdaptiveInstanceError.toString(), createAdaptiveInstanceError); } } 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, (T) clazz.newInstance()); instance = (T) EXTENSION_INSTANCES.get(clazz); } injectExtension(instance); Set<Class<?>> wrapperClasses = cachedWrapperClasses; if (wrapperClasses != null && wrapperClasses.size() > 0) { for (Class<?> wrapperClass : wrapperClasses) { instance = injectExtension((T) wrapperClass.getConstructor(type).newInstance(instance)); } } return instance; } catch (Throwable t) { throw new IllegalStateException("Extension instance(name: " + name + ", class: " + type + ") could not be instantiated: " + t.getMessage(), t); } } private T injectExtension(T instance) { try { if (objectFactory != null) { for (Method method : instance.getClass().getMethods()) { if (method.getName().startsWith("set") && method.getParameterTypes().length == 1 && Modifier.isPublic(method.getModifiers())) { Class<?> pt = method.getParameterTypes()[0]; try { String property = method.getName().length() > 3 ? method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4) : ""; Object object = objectFactory.getExtension(pt, property); if (object != null) { method.invoke(instance, object); } } catch (Exception e) { logger.error("fail to inject via method " + method.getName() + " of interface " + type.getName() + ": " + e.getMessage(), e); } } } } } catch (Exception e) { logger.error(e.getMessage(), e); } return instance; } private Class<?> getExtensionClass(String name) { if (type == null) throw new IllegalArgumentException("Extension type == null"); if (name == null) throw new IllegalArgumentException("Extension name == null"); Class<?> clazz = getExtensionClasses().get(name); if (clazz == null) throw new IllegalStateException("No such extension \"" + name + "\" for " + type.getName() + "!"); return clazz; } 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; } // 此方法已经getExtensionClasses方法同步过。 private Map<String, Class<?>> loadExtensionClasses() { final SPI defaultAnnotation = type.getAnnotation(SPI.class); if(defaultAnnotation != null) { String value = defaultAnnotation.value(); if(value != null && (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]; } } Map<String, Class<?>> extensionClasses = new HashMap<String, Class<?>>(); loadFile(extensionClasses, DUBBO_INTERNAL_DIRECTORY); loadFile(extensionClasses, DUBBO_DIRECTORY); loadFile(extensionClasses, SERVICES_DIRECTORY); return extensionClasses; } private void loadFile(Map<String, Class<?>> extensionClasses, String dir) { String fileName = dir + type.getName(); try { Enumeration<java.net.URL> urls; ClassLoader classLoader = findClassLoader(); if (classLoader != null) { urls = classLoader.getResources(fileName); } else { urls = ClassLoader.getSystemResources(fileName); } if (urls != null) { while (urls.hasMoreElements()) { java.net.URL url = urls.nextElement(); try { BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream(), "utf-8")); try { String line = 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(); line = line.substring(i + 1).trim(); } if (line.length() > 0) { Class<?> clazz = Class.forName(line, true, classLoader); if (! type.isAssignableFrom(clazz)) { throw new IllegalStateException("Error when load extension class(interface: " + type + ", class line: " + clazz.getName() + "), class " + clazz.getName() + "is not subtype of interface."); } if (clazz.isAnnotationPresent(Adaptive.class)) { if(cachedAdaptiveClass == null) { cachedAdaptiveClass = clazz; } else if (! cachedAdaptiveClass.equals(clazz)) { throw new IllegalStateException("More than 1 adaptive class found: " + cachedAdaptiveClass.getClass().getName() + ", " + clazz.getClass().getName()); } } else { try { clazz.getConstructor(type); Set<Class<?>> wrappers = cachedWrapperClasses; if (wrappers == null) { cachedWrapperClasses = new ConcurrentHashSet<Class<?>>(); wrappers = cachedWrapperClasses; } wrappers.add(clazz); } catch (NoSuchMethodException e) { clazz.getConstructor(); if (name == null || name.length() == 0) { name = findAnnotationName(clazz); if (name == null || name.length() == 0) { if (clazz.getSimpleName().length() > type.getSimpleName().length() && clazz.getSimpleName().endsWith(type.getSimpleName())) { name = clazz.getSimpleName().substring(0, clazz.getSimpleName().length() - type.getSimpleName().length()).toLowerCase(); } else { throw new IllegalStateException("No such extension name for the class " + clazz.getName() + " in the config " + url); } } } String[] names = NAME_SEPARATOR.split(name); if (names != null && names.length > 0) { Activate activate = clazz.getAnnotation(Activate.class); if (activate != null) { cachedActivates.put(names[0], activate); } for (String n : names) { if (! cachedNames.containsKey(clazz)) { cachedNames.put(clazz, n); } Class<?> c = extensionClasses.get(n); if (c == null) { extensionClasses.put(n, clazz); } else if (c != clazz) { throw new IllegalStateException("Duplicate extension " + type.getName() + " name " + n + " on " + c.getName() + " and " + clazz.getName()); } } } } } } } catch (Throwable t) { IllegalStateException e = new IllegalStateException("Failed to load extension class(interface: " + type + ", class line: " + line + ") in " + url + ", cause: " + t.getMessage(), t); exceptions.put(line, e); } } } // end of while read lines } finally { reader.close(); } } catch (Throwable t) { logger.error("Exception when load extension class(interface: " + type + ", class file: " + url + ") in " + url, t); } } // end of while urls } } catch (Throwable t) { logger.error("Exception when load extension class(interface: " + type + ", description file: " + fileName + ").", t); } } @SuppressWarnings("deprecation") private String findAnnotationName(Class<?> clazz) { com.alibaba.dubbo.common.Extension extension = clazz.getAnnotation(com.alibaba.dubbo.common.Extension.class); if (extension == null) { String name = clazz.getSimpleName(); if (name.endsWith(type.getSimpleName())) { name = name.substring(0, name.length() - type.getSimpleName().length()); } return name.toLowerCase(); } return extension.value(); } @SuppressWarnings("unchecked") private T createAdaptiveExtension() { try { return injectExtension((T) getAdaptiveExtensionClass().newInstance()); } catch (Exception e) { throw new IllegalStateException("Can not create adaptive extenstion " + type + ", cause: " + e.getMessage(), e); } } private Class<?> getAdaptiveExtensionClass() { getExtensionClasses(); if (cachedAdaptiveClass != null) { return cachedAdaptiveClass; } return cachedAdaptiveClass = createAdaptiveExtensionClass(); } private Class<?> createAdaptiveExtensionClass() { String code = createAdaptiveExtensionClassCode(); ClassLoader classLoader = findClassLoader(); com.alibaba.dubbo.common.compiler.Compiler compiler = ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.common.compiler.Compiler.class).getAdaptiveExtension(); return compiler.compile(code, classLoader); } private String createAdaptiveExtensionClassCode() { StringBuilder codeBuidler = new StringBuilder(); Method[] methods = type.getMethods(); boolean hasAdaptiveAnnotation = false; for(Method m : methods) { if(m.isAnnotationPresent(Adaptive.class)) { hasAdaptiveAnnotation = true; break; } } // 完全没有Adaptive方法,则不需要生成Adaptive类 if(! hasAdaptiveAnnotation) throw new IllegalStateException("No adaptive method on extension " + type.getName() + ", refuse to create the adaptive class!"); codeBuidler.append("package " + type.getPackage().getName() + ";"); codeBuidler.append("\nimport " + ExtensionLoader.class.getName() + ";"); codeBuidler.append("\npublic class " + type.getSimpleName() + "$Adpative" + " implements " + type.getCanonicalName() + " {"); for (Method method : methods) { Class<?> rt = method.getReturnType(); Class<?>[] pts = method.getParameterTypes(); Class<?>[] ets = method.getExceptionTypes(); Adaptive adaptiveAnnotation = method.getAnnotation(Adaptive.class); StringBuilder code = new StringBuilder(512); if (adaptiveAnnotation == null) { code.append("throw new UnsupportedOperationException(\"method ") .append(method.toString()).append(" of interface ") .append(type.getName()).append(" is not adaptive method!\");"); } else { int urlTypeIndex = -1; for (int i = 0; i < pts.length; ++i) { if (pts[i].equals(URL.class)) { urlTypeIndex = i; break; } } // 有类型为URL的参数 if (urlTypeIndex != -1) { // Null Point check String s = String.format("\nif (arg%d == null) throw new IllegalArgumentException(\"url == null\");", urlTypeIndex); code.append(s); s = String.format("\n%s url = arg%d;", URL.class.getName(), urlTypeIndex); code.append(s); } // 参数没有URL类型 else { String attribMethod = null; // 找到参数的URL属性 LBL_PTS: for (int i = 0; i < pts.length; ++i) { Method[] ms = pts[i].getMethods(); for (Method m : ms) { String name = m.getName(); if ((name.startsWith("get") || name.length() > 3) && Modifier.isPublic(m.getModifiers()) && !Modifier.isStatic(m.getModifiers()) && m.getParameterTypes().length == 0 && m.getReturnType() == URL.class) { urlTypeIndex = i; attribMethod = name; break LBL_PTS; } } } if(attribMethod == null) { throw new IllegalStateException("fail to create adative class for interface " + type.getName() + ": not found url parameter or url attribute in parameters of method " + method.getName()); } // Null point check String s = String.format("\nif (arg%d == null) throw new IllegalArgumentException(\"%s argument == null\");", urlTypeIndex, pts[urlTypeIndex].getName()); code.append(s); s = String.format("\nif (arg%d.%s() == null) throw new IllegalArgumentException(\"%s argument %s() == null\");", urlTypeIndex, attribMethod, pts[urlTypeIndex].getName(), attribMethod); code.append(s); s = String.format("%s url = arg%d.%s();",URL.class.getName(), urlTypeIndex, attribMethod); code.append(s); } String[] value = adaptiveAnnotation.value(); // 没有设置Key,则使用“扩展点接口名的点分隔 作为Key if(value.length == 0) { char[] charArray = type.getSimpleName().toCharArray(); StringBuilder sb = new StringBuilder(128); for (int i = 0; i < charArray.length; i++) { if(Character.isUpperCase(charArray[i])) { if(i != 0) { sb.append("."); } sb.append(Character.toLowerCase(charArray[i])); } else { sb.append(charArray[i]); } } value = new String[] {sb.toString()}; } boolean hasInvocation = false; for (int i = 0; i < pts.length; ++i) { if (pts[i].getName().equals("com.alibaba.dubbo.rpc.Invocation")) { // Null Point check String s = String.format("\nif (arg%d == null) throw new IllegalArgumentException(\"invocation == null\");", i); code.append(s); s = String.format("\nString methodName = arg%d.getMethodName();", i); code.append(s); hasInvocation = true; break; } } String defaultExtName = cachedDefaultName; String getNameCode = null; for (int i = value.length - 1; i >= 0; --i) { if(i == value.length - 1) { if(null != defaultExtName) { if(!"protocol".equals(value[i])) if (hasInvocation) getNameCode = String.format("url.getMethodParameter(methodName, \"%s\", \"%s\")", value[i], defaultExtName); else getNameCode = String.format("url.getParameter(\"%s\", \"%s\")", value[i], defaultExtName); else getNameCode = String.format("( url.getProtocol() == null ? \"%s\" : url.getProtocol() )", defaultExtName); } else { if(!"protocol".equals(value[i])) if (hasInvocation) getNameCode = String.format("url.getMethodParameter(methodName, \"%s\", \"%s\")", value[i], defaultExtName); else getNameCode = String.format("url.getParameter(\"%s\")", value[i]); else getNameCode = "url.getProtocol()"; } } else { if(!"protocol".equals(value[i])) if (hasInvocation) getNameCode = String.format("url.getMethodParameter(methodName, \"%s\", \"%s\")", value[i], defaultExtName); else getNameCode = String.format("url.getParameter(\"%s\", %s)", value[i], getNameCode); else getNameCode = String.format("url.getProtocol() == null ? (%s) : url.getProtocol()", getNameCode); } } code.append("\nString extName = ").append(getNameCode).append(";"); // check extName == null? String s = String.format("\nif(extName == null) " + "throw new IllegalStateException(\"Fail to get extension(%s) name from url(\" + url.toString() + \") use keys(%s)\");", type.getName(), Arrays.toString(value)); code.append(s); s = String.format("\n%s extension = (%<s)%s.getExtensionLoader(%s.class).getExtension(extName);", type.getName(), ExtensionLoader.class.getSimpleName(), type.getName()); code.append(s); // return statement if (!rt.equals(void.class)) { code.append("\nreturn "); } s = String.format("extension.%s(", method.getName()); code.append(s); for (int i = 0; i < pts.length; i++) { if (i != 0) code.append(", "); code.append("arg").append(i); } code.append(");"); } codeBuidler.append("\npublic " + rt.getCanonicalName() + " " + method.getName() + "("); for (int i = 0; i < pts.length; i ++) { if (i > 0) { codeBuidler.append(", "); } codeBuidler.append(pts[i].getCanonicalName()); codeBuidler.append(" "); codeBuidler.append("arg" + i); } codeBuidler.append(")"); if (ets.length > 0) { codeBuidler.append(" throws "); for (int i = 0; i < ets.length; i ++) { if (i > 0) { codeBuidler.append(", "); } codeBuidler.append(ets[i].getCanonicalName()); } } codeBuidler.append(" {"); codeBuidler.append(code.toString()); codeBuidler.append("\n}"); } codeBuidler.append("\n}"); if (logger.isDebugEnabled()) { logger.debug(codeBuidler.toString()); } return codeBuidler.toString(); } private static ClassLoader findClassLoader() { return ExtensionLoader.class.getClassLoader(); } @Override public String toString() { return this.getClass().getName() + "[" + type.getName() + "]"; } }