struts2中struts.xml 放置路径的问题

在搭建struts2项目时如果在web.xml中不指定struts.xml文件的路径，struts2会默认到/WEB-INF/classes中寻找加载其配置文件的，但我就是想把struts的配置文件放到我指定的位置下，这时该如何处理呢？我做了以下实验：

先看一下项目的文件结构：

我把struts的配置文件放到了/WEB-INF/deploy/pms/app-config/struts-config/下，并且在web.xml中的配置如下：

 <filter>
         <filter-name>struts2</filter-name>
         <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
          <init-param>
                <param-name>config</param-name>
                <param-value>
                      struts-default.xml,struts-plugin.xml,/WEB-INF/deploy/pms/app-config/struts-config/struts.xml
                    </param-value>
          </init-param>
     </filter>

     <filter-mapping>
         <filter-name>struts2</filter-name>
         <url-pattern>/*</url-pattern>
     </filter-mapping>

满怀信心的部署项目，并潇洒的启动tomcat，擦，不想看到的问题还是来了，打印信息如下：

为什么不能加载配置文件呢（保证配置文件是无误的），难道不能解析这个路径，那把配置文件放到src的指定文件夹下试试（因为它不是默认从src发布的文件夹下找嘛），

并且修改了web.xml

 <filter>
         <filter-name>struts2</filter-name>
         <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
          <init-param>
                <param-name>config</param-name>
                <param-value>
                      struts-default.xml,struts-plugin.xml,config/struts.xml
                    </param-value>
          </init-param>
     </filter>

     <filter-mapping>
         <filter-name>struts2</filter-name>
         <url-pattern>/*</url-pattern>
     </filter-mapping>

再次部署启动，居然没错了。郁闷。。。，难道我非得把配置文件放到src下吗，有点不甘心，看看你struts2的源码怎么读取文件的吧，从tomcat的打印信息中可以看到，加载配置文件的类是XmlConfigurationProvider

16:10:36,403  INFO ContextLoader:301 - Root WebApplicationContext: initialization completed in 2546 ms
16:10:36,622  INFO XmlConfigurationProvider:42 - Parsing configuration file [struts-default.xml]
16:10:36,763  INFO XmlConfigurationProvider:42 - Parsing configuration file [struts-plugin.xml]
16:10:36,809  INFO XmlConfigurationProvider:42 - Parsing configuration file [config/struts.xml]
16:10:37,059  INFO StrutsSpringObjectFactory:42 - Initializing Struts-Spring integration...

那就在struts2源码中直接找这个类，在这个类中搜了一下打印的日志信息“Unable to locate configuration files of the name”，找到这个信息是在XmlConfigurationProvider类的private List<Document> loadConfigurationFiles(String fileName, Element includeElement)方法中打印的，方法实现如下：

  private List<Document> loadConfigurationFiles(String fileName, Element includeElement) {
         List<Document> docs = new ArrayList<Document>();
         List<Document> finalDocs = new ArrayList<Document>();
         if (!includedFileNames.contains(fileName)) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("Loading action configurations from: " + fileName);
             }

             includedFileNames.add(fileName);

             Iterator<URL> urls = null;
             InputStream is = null;

             IOException ioException = null;
             try {
                 urls = getConfigurationUrls(fileName);
             } catch (IOException ex) {
                 ioException = ex;
             }

             if (urls == null || !urls.hasNext()) {
                 if (errorIfMissing) {
                     throw new ConfigurationException("Could not open files of the name " + fileName, ioException);
                 } else {
                     if (LOG.isInfoEnabled()) {
                     LOG.info("Unable to locate configuration files of the name "
                             + fileName + ", skipping");
                     }
                     return docs;
                 }
             }

             URL url = null;
             while (urls.hasNext()) {
                 try {
                     url = urls.next();
                     is = fileManager.loadFile(url);

                     InputSource in = new InputSource(is);

                     in.setSystemId(url.toString());

                     docs.add(DomHelper.parse(in, dtdMappings));
                 } catch (XWorkException e) {
                     if (includeElement != null) {
                         throw new ConfigurationException("Unable to load " + url, e, includeElement);
                     } else {
                         throw new ConfigurationException("Unable to load " + url, e);
                     }
                 } catch (Exception e) {
                     throw new ConfigurationException("Caught exception while loading file " + fileName, e, includeElement);
                 } finally {
                     if (is != null) {
                         try {
                             is.close();
                         } catch (IOException e) {
                             LOG.error("Unable to close input stream", e);
                         }
                     }
                 }
             }

             //sort the documents, according to the "order" attribute
             Collections.sort(docs, new Comparator<Document>() {
                 public int compare(Document doc1, Document doc2) {
                     return XmlHelper.getLoadOrder(doc1).compareTo(XmlHelper.getLoadOrder(doc2));
                 }
             });

             for (Document doc : docs) {
                 Element rootElement = doc.getDocumentElement();
                 NodeList children = rootElement.getChildNodes();
                 int childSize = children.getLength();

                 for (int i = 0; i < childSize; i++) {
                     Node childNode = children.item(i);

                     if (childNode instanceof Element) {
                         Element child = (Element) childNode;

                         final String nodeName = child.getNodeName();

                         if ("include".equals(nodeName)) {
                             String includeFileName = child.getAttribute("file");
                             if (includeFileName.indexOf('*') != -1) {
                                 // handleWildCardIncludes(includeFileName, docs, child);
                                 ClassPathFinder wildcardFinder = new ClassPathFinder();
                                 wildcardFinder.setPattern(includeFileName);
                                 Vector<String> wildcardMatches = wildcardFinder.findMatches();
                                 for (String match : wildcardMatches) {
                                     finalDocs.addAll(loadConfigurationFiles(match, child));
                                 }
                             } else {
                                 finalDocs.addAll(loadConfigurationFiles(includeFileName, child));
                             }
                         }
                     }
                 }
                 finalDocs.add(doc);
                 loadedFileUrls.add(url.toString());
             }

             if (LOG.isDebugEnabled()) {
                 LOG.debug("Loaded action configuration from: " + fileName);
             }
         }
         return finalDocs;
     }

在方法的16行，该方法又调用了getConfigurationUrls（filename）方法：

  protected Iterator<URL> getConfigurationUrls(String fileName) throws IOException {
         return ClassLoaderUtil.getResources(fileName, XmlConfigurationProvider.class, false);
     }

水还真是深，在getConfigurationUrls（filename）方法中又调用了其他类的方法，ClassLoaderUtil.getResources(fileName, XmlConfigurationProvider.class, false)方法如下：

  public static Iterator<URL> getResources(String resourceName, Class callingClass, boolean aggregate) throws IOException {

          AggregateIterator<URL> iterator = new AggregateIterator<URL>();

          iterator.addEnumeration(Thread.currentThread().getContextClassLoader().getResources(resourceName));

          if (!iterator.hasNext() || aggregate) {
              iterator.addEnumeration(ClassLoaderUtil.class.getClassLoader().getResources(resourceName));
          }

          if (!iterator.hasNext() || aggregate) {
              ClassLoader cl = callingClass.getClassLoader();

              if (cl != null) {
                  iterator.addEnumeration(cl.getResources(resourceName));
              }
          }

          if (!iterator.hasNext() && (resourceName != null) && ((resourceName.length() == 0) || (resourceName.charAt(0) != '/'))) {
              return getResources('/' + resourceName, callingClass, aggregate);
          }

          return iterator;
      }

也该到尽头了吧！！从代码中可以看出，struts加载的配置文件都是从类加载器加载.class文件的路径中去寻找的，把配置文件放到WEB-INF下，它当然加载不到了，除非你写成http://xxx/工程名+配置文件路径,否则只能把配置文件写到src下了，这点struts2设计的还真是让人有点郁闷！