spring读取xml配置文件（二）

一、当spring解析完配置文件名的占位符后，就开始refresh容器

@Override
    public void refresh() throws BeansException, IllegalStateException {
        synchronized (this.startupShutdownMonitor) {
            // Prepare this context for refreshing.
              //设置了启动时间，激活状态设为true，初始化一些propertySource
              //初始化的时候啥都没做，是个空方法。设置状态为开启
            prepareRefresh();

            // Tell the subclass to refresh the internal bean factory.
              //这个方法内部刷新了BeanFactory，如果BeanFactory存在，那么先销毁，然后
              //重新创建新的BeanFactory
            ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

            // Prepare the bean factory for use in this context.
            prepareBeanFactory(beanFactory);

            try {
                // Allows post-processing of the bean factory in context subclasses.
                postProcessBeanFactory(beanFactory);

                // Invoke factory processors registered as beans in the context.
                invokeBeanFactoryPostProcessors(beanFactory);

                // Register bean processors that intercept bean creation.
                registerBeanPostProcessors(beanFactory);

                // Initialize message source for this context.
                initMessageSource();

                // Initialize event multicaster for this context.
                initApplicationEventMulticaster();

                // Initialize other special beans in specific context subclasses.
                onRefresh();

                // Check for listener beans and register them.
                registerListeners();

                // Instantiate all remaining (non-lazy-init) singletons.
                finishBeanFactoryInitialization(beanFactory);

                // Last step: publish corresponding event.
                finishRefresh();
            }

            catch (BeansException ex) {
                if (logger.isWarnEnabled()) {
                    logger.warn("Exception encountered during context initialization - " +
                            "cancelling refresh attempt: " + ex);
                }

                // Destroy already created singletons to avoid dangling resources.
                destroyBeans();

                // Reset 'active' flag.
                cancelRefresh(ex);

                // Propagate exception to caller.
                throw ex;
            }

            finally {
                // Reset common introspection caches in Spring's core, since we
                // might not ever need metadata for singleton beans anymore...
                resetCommonCaches();
            }
        }
    }

第7行设置了容器启动的时间，容器的状态被修改为false，表示已经启动，并且初始化PropertySource,不过初始化PropertySource内部的代码是空的，什么都没做。

第12行代码是对BeanFactory进行刷新，它调用了refreBeanFactory方法它的代码如下

@Override
    protected final void refreshBeanFactory() throws BeansException {
        if (hasBeanFactory()) {
            destroyBeans();
            closeBeanFactory();
        }
        try {
            DefaultListableBeanFactory beanFactory = createBeanFactory();
            beanFactory.setSerializationId(getId());
            customizeBeanFactory(beanFactory);
            loadBeanDefinitions(beanFactory);
            synchronized (this.beanFactoryMonitor) {
                this.beanFactory = beanFactory;
            }
        }
        catch (IOException ex) {
            throw new ApplicationContextException("I/O error parsing bean definition source for " + getDisplayName(), ex);
        }
    }

首先判断这个Bean工厂是否已经存在，如果存在了就直接销毁，重新创建一个DefaultListableBeanFactory工厂，

这个工厂在创建的时候初始化了许多的容器字段，如是否可以在覆盖同名不同定义的bean定义，beanName->beanDefinition容器and so on.

    /** Optional id for this factory, for serialization purposes */
    private String serializationId;

    /** Whether to allow re-registration of a different definition with the same name */
    private boolean allowBeanDefinitionOverriding = true;

    /** Whether to allow eager class loading even for lazy-init beans */
    private boolean allowEagerClassLoading = true;

    /** Optional OrderComparator for dependency Lists and arrays */
    private Comparator<Object> dependencyComparator;

    /** Resolver to use for checking if a bean definition is an autowire candidate */
    private AutowireCandidateResolver autowireCandidateResolver = new SimpleAutowireCandidateResolver();

    /** Map from dependency type to corresponding autowired value */
    private final Map<Class<?>, Object> resolvableDependencies = new ConcurrentHashMap<Class<?>, Object>(16);

    /** Map of bean definition objects, keyed by bean name */
    private final Map<String, BeanDefinition> beanDefinitionMap = new ConcurrentHashMap<String, BeanDefinition>(256);

    /** Map of singleton and non-singleton bean names, keyed by dependency type */
    private final Map<Class<?>, String[]> allBeanNamesByType = new ConcurrentHashMap<Class<?>, String[]>(64);

    /** Map of singleton-only bean names, keyed by dependency type */
    private final Map<Class<?>, String[]> singletonBeanNamesByType = new ConcurrentHashMap<Class<?>, String[]>(64);

    /** List of bean definition names, in registration order */
    private volatile List<String> beanDefinitionNames = new ArrayList<String>(256);

    /** List of names of manually registered singletons, in registration order */
    private volatile Set<String> manualSingletonNames = new LinkedHashSet<String>(16);

并且给这个Bean工厂设置序列化的id，这个序列化ID是工厂类的全限定名+@+这个工厂实例的hashcode

第10行customizeBeanFactory方法是在AbstractRefreshableApplicationContext类中定义的它的代码如下

if (this.allowBeanDefinitionOverriding != null) {
beanFactory.setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
}
if (this.allowCircularReferences != null) {
beanFactory.setAllowCircularReferences(this.allowCircularReferences);
}

如果这个应用上下文没有定义能否bean定义覆盖和循环依赖这两个属性就使用默认值，默认值都是为true

第11行代码loadBeanDefinitions(beanFactory)创建了的XmlBeanDefinitionReader实例，它的继承结构，继承自抽象的bean定义阅读器

这个方法内部的代码如下

@Override
    protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) throws BeansException, IOException {
        // Create a new XmlBeanDefinitionReader for the given BeanFactory.
        XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory);

        // Configure the bean definition reader with this context's
        // resource loading environment.
        beanDefinitionReader.setEnvironment(this.getEnvironment());
        beanDefinitionReader.setResourceLoader(this);
        beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this));

        // Allow a subclass to provide custom initialization of the reader,
        // then proceed with actually loading the bean definitions.
        initBeanDefinitionReader(beanDefinitionReader);
        loadBeanDefinitions(beanDefinitionReader);
    }

第8行将ClasspathXmlApplicationContext中的环境变量设置到新创建的bean定义阅读器，把ClasspathXmlApplicationContext(它继承了ResourceLoader接口)资源加载器设置进去，设置实体解析器，这个解析器，实现的接口时EntityResolver，它的实现类有好多，这里设置的是一个SAX解析器，用于读取xml，这里绕来绕去的，看下ClasspathXmlApplicationContext的继承结构.

 第14行初始化bean定义阅读器，它主要是对这个xml阅读器进行了验证模式的设置，是自动验证还是不验证

第15行传入xml阅读器，准备读取xml，这个方法的代码如下

protected void loadBeanDefinitions(XmlBeanDefinitionReader reader) throws BeansException, IOException {
        Resource[] configResources = getConfigResources();
        if (configResources != null) {
            reader.loadBeanDefinitions(configResources);
        }
        String[] configLocations = getConfigLocations();
        if (configLocations != null) {
            reader.loadBeanDefinitions(configLocations);
        }
    }

 第8行将配置文件传入阅读器，loadBeanDefinitions方法的代码如下

public int loadBeanDefinitions(String location, Set<Resource> actualResources) throws BeanDefinitionStoreException {
        ResourceLoader resourceLoader = getResourceLoader();
        if (resourceLoader == null) {
            throw new BeanDefinitionStoreException(
                    "Cannot import bean definitions from location [" + location + "]: no ResourceLoader available");
        }

        if (resourceLoader instanceof ResourcePatternResolver) {
            // Resource pattern matching available.
            try {
                Resource[] resources = ((ResourcePatternResolver) resourceLoader).getResources(location);
                int loadCount = loadBeanDefinitions(resources);
                if (actualResources != null) {
                    for (Resource resource : resources) {
                        actualResources.add(resource);
                    }
                }
                if (logger.isDebugEnabled()) {
                    logger.debug("Loaded " + loadCount + " bean definitions from location pattern [" + location + "]");
                }
                return loadCount;
            }
            catch (IOException ex) {
                throw new BeanDefinitionStoreException(
                        "Could not resolve bean definition resource pattern [" + location + "]", ex);
            }
        }
        else {
            // Can only load single resources by absolute URL.
            Resource resource = resourceLoader.getResource(location);
            int loadCount = loadBeanDefinitions(resource);
            if (actualResources != null) {
                actualResources.add(resource);
            }
            if (logger.isDebugEnabled()) {
                logger.debug("Loaded " + loadCount + " bean definitions from location [" + location + "]");
            }
            return loadCount;
        }
    }

第2行这个resourceLoader 是之前创建XmlBeanDefinitionReader这个xml阅读器传进来的ClasspathXmlApplictionContext,这个类，在上面的图已经告诉了我们它是ResourceLoader的子类

第11行开始进入资源的解析，也就是对配置文件的路径找到所有的xml，并与之匹配，详细情况继续往下

@Override
    public Resource[] getResources(String locationPattern) throws IOException {
        return this.resourcePatternResolver.getResources(locationPattern);
    }

第3行的resourcePatternResolver是一个PathMatchingResourcePatternResolver的实例，这个实例在创建ClasspathXmlApplicationContext的时候调用父类AbstractApplicationContext时被创建。这些路径匹配器的继承结构为

继续进入PathMatchingResourcePatternResolver的getResources方法

@Override
    public Resource[] getResources(String locationPattern) throws IOException {
        Assert.notNull(locationPattern, "Location pattern must not be null");
        if (locationPattern.startsWith(CLASSPATH_ALL_URL_PREFIX)) {
            // a class path resource (multiple resources for same name possible)
            if (getPathMatcher().isPattern(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()))) {
                // a class path resource pattern
                return findPathMatchingResources(locationPattern);
            }
            else {
                // all class path resources with the given name
                return findAllClassPathResources(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()));
            }
        }
        else {
            // Only look for a pattern after a prefix here
            // (to not get fooled by a pattern symbol in a strange prefix).
            int prefixEnd = locationPattern.indexOf(":") + 1;
            if (getPathMatcher().isPattern(locationPattern.substring(prefixEnd))) {
                // a file pattern
                return findPathMatchingResources(locationPattern);
            }
            else {
                // a single resource with the given name
                return new Resource[] {getResourceLoader().getResource(locationPattern)};
            }
        }
    }

第4行中的CLASSPATH_ALL_URL_PREFIX的值为classpath*：，这里是判断这个配置文件是不是以classpath*：开头的，如果不是那么就跳到第18行，取得：后面的字符串，如：classpath：spring/spring-*.xml或者spring/spring-*.xml最终都会得到spring/spring-*.xml这个字符串。如果这个字符串不含通配符，那么直接包装成resource数组返回。

第6行getPathMatcher()获得一个AntPathMatcher实例调用isPattern判断这个配置文件是不是使用了*或者？通配符的，代码如下。

@Override
    public boolean isPattern(String path) {
        return (path.indexOf('*') != -1 || path.indexOf('?') != -1);
     }

如果有通配符就执行第8行，如果没有就执行第12行，

第12行的findAllClassPathResources方法，获取各加载器的类路径下的所有名字匹配的配置文件，假如配置文件叫做classpath*：spring/spring-context.xml,那么它先从父加载器中找。

它调用的classLoader的getResoures方法，代码如下：

protected Set<Resource> doFindAllClassPathResources(String path) throws IOException {
        Set<Resource> result = new LinkedHashSet<Resource>(16);
        ClassLoader cl = getClassLoader();
        Enumeration<URL> resourceUrls = (cl != null ? cl.getResources(path) : ClassLoader.getSystemResources(path));
        while (resourceUrls.hasMoreElements()) {
            URL url = resourceUrls.nextElement();
            result.add(convertClassLoaderURL(url));
        }
        if ("".equals(path)) {
            // The above result is likely to be incomplete, i.e. only containing file system references.
            // We need to have pointers to each of the jar files on the classpath as well...
            addAllClassLoaderJarRoots(cl, result);
        }
        return result;
    }

第12行addAllClassLoaderJarRoots方法是在只写了classpath*：前缀，却没有指定配置文件的情况下调用，它还会去寻找jar文件，然后包装成resource返回

第4行就调用了getResources方法，看看getResources方法的代码，parent值得是父加载器。

public Enumeration<URL> getResources(String name) throws IOException {
        @SuppressWarnings("unchecked")
        Enumeration<URL>[] tmp = (Enumeration<URL>[]) new Enumeration<?>[2];
        if (parent != null) {
            tmp[0] = parent.getResources(name);
        } else {
            tmp[0] = getBootstrapResources(name);
        }
        tmp[1] = findResources(name);

        return new CompoundEnumeration<>(tmp);
    }

如果配置文件的路径里有通配符，那么会进入findPathMatchingResources方法

protected Resource[] findPathMatchingResources(String locationPattern) throws IOException {
        String rootDirPath = determineRootDir(locationPattern);
        String subPattern = locationPattern.substring(rootDirPath.length());
        Resource[] rootDirResources = getResources(rootDirPath);
        Set<Resource> result = new LinkedHashSet<Resource>(16);
        for (Resource rootDirResource : rootDirResources) {
            rootDirResource = resolveRootDirResource(rootDirResource);
 8             if (rootDirResource.getURL().getProtocol().startsWith(ResourceUtils.URL_PROTOCOL_VFS)) {
                result.addAll(VfsResourceMatchingDelegate.findMatchingResources(rootDirResource, subPattern, getPathMatcher()));
            }
            else if (isJarResource(rootDirResource)) {
                result.addAll(doFindPathMatchingJarResources(rootDirResource, subPattern));
            }
            else {
                result.addAll(doFindPathMatchingFileResources(rootDirResource, subPattern));
            }
        }
        if (logger.isDebugEnabled()) {
            logger.debug("Resolved location pattern [" + locationPattern + "] to resources " + result);
        }
        return result.toArray(new Resource[result.size()]);
    }

第二行的determineRootDir方法的代码如下，仍然要判断是否是通配符的配置文件，如果是那么寻找最后一个/，如果找到就截取这个/前面的一段字符串，如：classpath*：spring/spring-*context.xml,就会被获取到classpath*:spring/这一段，如果没有/就取到classpath*：

protected String determineRootDir(String location) {
        int prefixEnd = location.indexOf(":") + 1;
        int rootDirEnd = location.length();
        while (rootDirEnd > prefixEnd && getPathMatcher().isPattern(location.substring(prefixEnd, rootDirEnd))) {
            rootDirEnd = location.lastIndexOf('/', rootDirEnd - 2) + 1;
        }
        if (rootDirEnd == 0) {
            rootDirEnd = prefixEnd;
        }
        return location.substring(0, rootDirEnd);
    }

第3行表示截取通配符那一段，如classpath*：spring/spring-*.xml,会获取到spring-*.xml

第4行是从rootDir下找，如classpath*:spring/下找所有的配置文件，这段代码上面分析过，不过可以长话短说的再分析一遍，假设当前的locationPattern就是classpath*:spring/

 @Override
     public Resource[] getResources(String locationPattern) throws IOException {
         Assert.notNull(locationPattern, "Location pattern must not be null");
         if (locationPattern.startsWith(CLASSPATH_ALL_URL_PREFIX)) {
             // a class path resource (multiple resources for same name possible)
             if (getPathMatcher().isPattern(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()))) {
                 // a class path resource pattern
                 return findPathMatchingResources(locationPattern);
             }
             else {
                 // all class path resources with the given name
                 return findAllClassPathResources(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()));
             }
         }
         else {
             // Only look for a pattern after a prefix here
             // (to not get fooled by a pattern symbol in a strange prefix).
             int prefixEnd = locationPattern.indexOf(":") + 1;
             if (getPathMatcher().isPattern(locationPattern.substring(prefixEnd))) {
                 // a file pattern
                 return findPathMatchingResources(locationPattern);
             }
             else {
                 // a single resource with the given name
                 return new Resource[] {getResourceLoader().getResource(locationPattern)};
             }
         }
     }

先判断是否是以classpath*:,如果是，那再判断带不带通配符，如果不带，直接调用findAllClassPathResources方法，调用所有的加载器，先从父类开始，在所有的加载器的类路径包装成resource。

第6行循环根路径开始寻找配置文件了

第7行对路径进行解析，判断是否为OSGI类型的路径

第8行，判断是不是vfs协议的文件资源路径

第11行判断是不是jar类型的资源路径

第15行开始查找了，只要看到do开头的方法，基本就是开始真正开始办事了

protected Set<Resource> doFindPathMatchingFileResources(Resource rootDirResource, String subPattern)
            throws IOException {

        File rootDir;
        try {
            rootDir = rootDirResource.getFile().getAbsoluteFile();
        }
        catch (IOException ex) {
            if (logger.isWarnEnabled()) {
                logger.warn("Cannot search for matching files underneath " + rootDirResource +
                        " because it does not correspond to a directory in the file system", ex);
            }
            return Collections.emptySet();
        }
        return doFindMatchingFileSystemResources(rootDir, subPattern);
    }

第6行拿到这个根路径的绝对地址，最后再第15行调用doFindMatchingFileSystemResources,传入了俩个参数，一个是根路径，另一个就含通配符的那个字符串

protected Set<Resource> doFindMatchingFileSystemResources(File rootDir, String subPattern) throws IOException {
        if (logger.isDebugEnabled()) {
            logger.debug("Looking for matching resources in directory tree [" + rootDir.getPath() + "]");
        }
        Set<File> matchingFiles = retrieveMatchingFiles(rootDir, subPattern);
        Set<Resource> result = new LinkedHashSet<Resource>(matchingFiles.size());
        for (File file : matchingFiles) {
            result.add(new FileSystemResource(file));
        }
        return result;
    }

直接看第5行的retrieveMatchingFiles方法代码

protected Set<File> retrieveMatchingFiles(File rootDir, String pattern) throws IOException {
        if (!rootDir.exists()) {
            // Silently skip non-existing directories.
            if (logger.isDebugEnabled()) {
                logger.debug("Skipping [" + rootDir.getAbsolutePath() + "] because it does not exist");
            }
            return Collections.emptySet();
        }
        if (!rootDir.isDirectory()) {
            // Complain louder if it exists but is no directory.
            if (logger.isWarnEnabled()) {
                logger.warn("Skipping [" + rootDir.getAbsolutePath() + "] because it does not denote a directory");
            }
            return Collections.emptySet();
        }
        if (!rootDir.canRead()) {
            if (logger.isWarnEnabled()) {
                logger.warn("Cannot search for matching files underneath directory [" + rootDir.getAbsolutePath() +
                        "] because the application is not allowed to read the directory");
            }
            return Collections.emptySet();
        }
        String fullPattern = StringUtils.replace(rootDir.getAbsolutePath(), File.separator, "/");
        if (!pattern.startsWith("/")) {
            fullPattern += "/";
        }
        fullPattern = fullPattern + StringUtils.replace(pattern, File.separator, "/");
        Set<File> result = new LinkedHashSet<File>(8);
        doRetrieveMatchingFiles(fullPattern, rootDir, result);
        return result;
    }

如果根路径不存在或者是个目录或者是不可读的，那么直接返回一个空的集合

第23行，将\替换成/

第28行，将绝对根路径和通配符字符串连接起来

第29行，我们又看到do开头的方法了，好高兴，进去看看，fullPattern 是全路径，dir是根路径，result是用来装资源的

protected void doRetrieveMatchingFiles(String fullPattern, File dir, Set<File> result) throws IOException {
        if (logger.isDebugEnabled()) {
            logger.debug("Searching directory [" + dir.getAbsolutePath() +
                    "] for files matching pattern [" + fullPattern + "]");
        }
        File[] dirContents = dir.listFiles();
        if (dirContents == null) {
            if (logger.isWarnEnabled()) {
                logger.warn("Could not retrieve contents of directory [" + dir.getAbsolutePath() + "]");
            }
            return;
        }
        for (File content : dirContents) {
            String currPath = StringUtils.replace(content.getAbsolutePath(), File.separator, "/");
            if (content.isDirectory() && getPathMatcher().matchStart(fullPattern, currPath + "/")) {
                if (!content.canRead()) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("Skipping subdirectory [" + dir.getAbsolutePath() +
                                "] because the application is not allowed to read the directory");
                    }
                }
                else {
                    doRetrieveMatchingFiles(fullPattern, content, result);
                }
            }
            if (getPathMatcher().match(fullPattern, currPath)) {
                result.add(content);
            }
        }
    }

第6行得到了根路径下的所有文件，循环这些file，如果是目录，那么继续匹配，调用matchStart方法，这个方法里面又调用了doMatch方法

protected boolean doMatch(String pattern, String path, boolean fullMatch, Map<String, String> uriTemplateVariables) {
        if (path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
            return false;
        }

        String[] pattDirs = tokenizePattern(pattern);
        String[] pathDirs = tokenizePath(path);

        int pattIdxStart = 0;
        int pattIdxEnd = pattDirs.length - 1;
        int pathIdxStart = 0;
        int pathIdxEnd = pathDirs.length - 1;

        // Match all elements up to the first **
        while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
            String pattDir = pattDirs[pattIdxStart];
            if ("**".equals(pattDir)) {
                break;
            }
            if (!matchStrings(pattDir, pathDirs[pathIdxStart], uriTemplateVariables)) {
                return false;
            }
            pattIdxStart++;
            pathIdxStart++;
        }

        if (pathIdxStart > pathIdxEnd) {
            // Path is exhausted, only match if rest of pattern is * or **'s
            if (pattIdxStart > pattIdxEnd) {
                return (pattern.endsWith(this.pathSeparator) ? path.endsWith(this.pathSeparator) :
                        !path.endsWith(this.pathSeparator));
            }
            if (!fullMatch) {
                return true;
            }
            if (pattIdxStart == pattIdxEnd && pattDirs[pattIdxStart].equals("*") && path.endsWith(this.pathSeparator)) {
                return true;
            }
            for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
                if (!pattDirs[i].equals("**")) {
                    return false;
                }
            }
            return true;
        }
        else if (pattIdxStart > pattIdxEnd) {
            // String not exhausted, but pattern is. Failure.
            return false;
        }
        else if (!fullMatch && "**".equals(pattDirs[pattIdxStart])) {
            // Path start definitely matches due to "**" part in pattern.
            return true;
        }

        // up to last '**'
        while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
            String pattDir = pattDirs[pattIdxEnd];
            if (pattDir.equals("**")) {
                break;
            }
            if (!matchStrings(pattDir, pathDirs[pathIdxEnd], uriTemplateVariables)) {
                return false;
            }
            pattIdxEnd--;
            pathIdxEnd--;
        }
        if (pathIdxStart > pathIdxEnd) {
            // String is exhausted
            for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
                if (!pattDirs[i].equals("**")) {
                    return false;
                }
            }
            return true;
        }

        while (pattIdxStart != pattIdxEnd && pathIdxStart <= pathIdxEnd) {
            int patIdxTmp = -1;
            for (int i = pattIdxStart + 1; i <= pattIdxEnd; i++) {
                if (pattDirs[i].equals("**")) {
                    patIdxTmp = i;
                    break;
                }
            }
            if (patIdxTmp == pattIdxStart + 1) {
                // '**/**' situation, so skip one
                pattIdxStart++;
                continue;
            }
            // Find the pattern between padIdxStart & padIdxTmp in str between
            // strIdxStart & strIdxEnd
            int patLength = (patIdxTmp - pattIdxStart - 1);
            int strLength = (pathIdxEnd - pathIdxStart + 1);
            int foundIdx = -1;

            strLoop:
            for (int i = 0; i <= strLength - patLength; i++) {
                for (int j = 0; j < patLength; j++) {
                    String subPat = pattDirs[pattIdxStart + j + 1];
                    String subStr = pathDirs[pathIdxStart + i + j];
                    if (!matchStrings(subPat, subStr, uriTemplateVariables)) {
                        continue strLoop;
                    }
                }
                foundIdx = pathIdxStart + i;
                break;
            }

            if (foundIdx == -1) {
                return false;
            }

            pattIdxStart = patIdxTmp;
            pathIdxStart = foundIdx + patLength;
        }

        for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
            if (!pattDirs[i].equals("**")) {
                return false;
            }
        }

        return true;
    }

第6,7行将路径按照/进行分割成字符串数组

第17行，如果发现通配符出现**，那么退出循环，跳到第50行判断是不是全匹配，如果不是全匹配那么就返回true

如果fullMatcher为true，那么就跳到56行，从后往前匹配，如果中间出现任何不匹配的就返回false，如果都匹配，那么会匹配到**，那么又退出循环，跳到第117行，此时可以确定返回true了

如果没有通配符的情况下，并且都验证通过，那么会进入第21行进行验证，得看看匹配路径是否是目录，如果是目录那么就匹配失败。

第61行，这里会把通配符*和？替换成正则表达式，替换的逻辑代码如下：

public AntPathStringMatcher(String pattern, boolean caseSensitive) {
            StringBuilder patternBuilder = new StringBuilder();
            Matcher matcher = GLOB_PATTERN.matcher(pattern);
            int end = 0;
            while (matcher.find()) {
                patternBuilder.append(quote(pattern, end, matcher.start()));
                String match = matcher.group();
                if ("?".equals(match)) {
                    patternBuilder.append('.');
                }
                else if ("*".equals(match)) {
                    patternBuilder.append(".*");
                }
                else if (match.startsWith("{") && match.endsWith("}")) {
                    int colonIdx = match.indexOf(':');
                    if (colonIdx == -1) {
                        patternBuilder.append(DEFAULT_VARIABLE_PATTERN);
                        this.variableNames.add(matcher.group(1));
                    }
                    else {
                        String variablePattern = match.substring(colonIdx + 1, match.length() - 1);
                        patternBuilder.append('(');
                        patternBuilder.append(variablePattern);
                        patternBuilder.append(')');
                        String variableName = match.substring(1, colonIdx);
                        this.variableNames.add(variableName);
                    }
                }
                end = matcher.end();
            }
            patternBuilder.append(quote(pattern, end, pattern.length()));
            this.pattern = (caseSensitive ? Pattern.compile(patternBuilder.toString()) :
                    Pattern.compile(patternBuilder.toString(), Pattern.CASE_INSENSITIVE));
        }

 第6行将截取从0开始到找到第一个匹配的子字符串的位置的字符串，并加上单引号，如：spring-*.xml 会截取到'spring-'这样的字符串

第七行获得匹配的字符串，这里是*

下面进行了判断，如果是*，那么就替换成.*追加到字符串后面

找到匹配的配置文件后，就添加到一个set集合中

最后我们再回到doFindMatchingFileSystemResources方法

protected Set<Resource> doFindMatchingFileSystemResources(File rootDir, String subPattern) throws IOException {
        if (logger.isDebugEnabled()) {
            logger.debug("Looking for matching resources in directory tree [" + rootDir.getPath() + "]");
        }
        Set<File> matchingFiles = retrieveMatchingFiles(rootDir, subPattern);
        Set<Resource> result = new LinkedHashSet<Resource>(matchingFiles.size());
        for (File file : matchingFiles) {
            result.add(new FileSystemResource(file));
        }
        return result;
    }

第8表示这些文件都被打包成resource加到set集合里，最后一只返回到AbstractBeanDefinition类的loadBeanDefinitions方法

public int loadBeanDefinitions(String location, Set<Resource> actualResources) throws BeanDefinitionStoreException {
        ResourceLoader resourceLoader = getResourceLoader();
        if (resourceLoader == null) {
            throw new BeanDefinitionStoreException(
                    "Cannot import bean definitions from location [" + location + "]: no ResourceLoader available");
        }

        if (resourceLoader instanceof ResourcePatternResolver) {
            // Resource pattern matching available.
            try {
                Resource[] resources = ((ResourcePatternResolver) resourceLoader).getResources(location);
                int loadCount = loadBeanDefinitions(resources);
                if (actualResources != null) {
                    for (Resource resource : resources) {
                        actualResources.add(resource);
                    }
                }
                if (logger.isDebugEnabled()) {
                    logger.debug("Loaded " + loadCount + " bean definitions from location pattern [" + location + "]");
                }
                return loadCount;
            }
            catch (IOException ex) {
                throw new BeanDefinitionStoreException(
                        "Could not resolve bean definition resource pattern [" + location + "]", ex);
            }
        }
        else {
            // Can only load single resources by absolute URL.
            Resource resource = resourceLoader.getResource(location);
            int loadCount = loadBeanDefinitions(resource);
            if (actualResources != null) {
                actualResources.add(resource);
            }
            if (logger.isDebugEnabled()) {
                logger.debug("Loaded " + loadCount + " bean definitions from location [" + location + "]");
            }
            return loadCount;
        }
    }

第12行，调用了重载方法loadBeanDefinitions（Resource[]）,方法调用一直进入到了XmlBeanDefinitionReader类中的loadBeanDefinitions方法

    public int loadBeanDefinitions(EncodedResource encodedResource) throws BeanDefinitionStoreException {
        Assert.notNull(encodedResource, "EncodedResource must not be null");
        if (logger.isInfoEnabled()) {
            logger.info("Loading XML bean definitions from " + encodedResource.getResource());
        }

        Set<EncodedResource> currentResources = this.resourcesCurrentlyBeingLoaded.get();
        if (currentResources == null) {
            currentResources = new HashSet<EncodedResource>(4);
            this.resourcesCurrentlyBeingLoaded.set(currentResources);
        }
        if (!currentResources.add(encodedResource)) {
            throw new BeanDefinitionStoreException(
                    "Detected cyclic loading of " + encodedResource + " - check your import definitions!");
        }
        try {
            InputStream inputStream = encodedResource.getResource().getInputStream();
            try {
                InputSource inputSource = new InputSource(inputStream);
                if (encodedResource.getEncoding() != null) {
                    inputSource.setEncoding(encodedResource.getEncoding());
                }
                return doLoadBeanDefinitions(inputSource, encodedResource.getResource());
            }
            finally {
                inputStream.close();
            }
        }
        catch (IOException ex) {
            throw new BeanDefinitionStoreException(
                    "IOException parsing XML document from " + encodedResource.getResource(), ex);
        }
        finally {
            currentResources.remove(encodedResource);
            if (currentResources.isEmpty()) {
                this.resourcesCurrentlyBeingLoaded.remove();
            }
        }
    }

第17行，拿到这个配置文件的输入流，并包装成InputSource，这个时候我们又看到了do开头的方法doLoadBeanDefinitions，它的代码为

try {
            Document doc = doLoadDocument(inputSource, resource);
            return registerBeanDefinitions(doc, resource);
        }

看到第二行，这个配置文件被加载成了Document对象，在进入doLoadDocument方法

protected Document doLoadDocument(InputSource inputSource, Resource resource) throws Exception {
        return this.documentLoader.loadDocument(inputSource, getEntityResolver(), this.errorHandler,
                getValidationModeForResource(resource), isNamespaceAware());
    }

看到第3行，获得验证模式，它是根据这个xml的是否以DOCTYPE开头来确定时dtd验证还是xsd验证

public int detectValidationMode(InputStream inputStream) throws IOException {
        // Peek into the file to look for DOCTYPE.
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        try {
            boolean isDtdValidated = false;
            String content;
            while ((content = reader.readLine()) != null) {
                content = consumeCommentTokens(content);
                if (this.inComment || !StringUtils.hasText(content)) {
                    continue;
                }
                if (hasDoctype(content)) {
                    isDtdValidated = true;
                    break;
                }
                if (hasOpeningTag(content)) {
                    // End of meaningful data...
                    break;
                }
            }
            return (isDtdValidated ? VALIDATION_DTD : VALIDATION_XSD);
        }
        catch (CharConversionException ex) {
            // Choked on some character encoding...
            // Leave the decision up to the caller.
            return VALIDATION_AUTO;
        }
        finally {
            reader.close();
        }
    }

第12行的hasDoctype方法

private boolean hasDoctype(String content) {
        return content.contains(DOCTYPE);
    }

DOCTYPE的值就是DOCTYPE字符串

看看document是怎么创建的

@Override
    public Document loadDocument(InputSource inputSource, EntityResolver entityResolver,
            ErrorHandler errorHandler, int validationMode, boolean namespaceAware) throws Exception {

        DocumentBuilderFactory factory = createDocumentBuilderFactory(validationMode, namespaceAware);
        if (logger.isDebugEnabled()) {
            logger.debug("Using JAXP provider [" + factory.getClass().getName() + "]");
        }
        DocumentBuilder builder = createDocumentBuilder(factory, entityResolver, errorHandler);
        return builder.parse(inputSource);
    }

首先在第5行创建了一个文档构建工厂，然后通过工厂创建构建者，最后用构建者解析输入资源，返回一个文档对象，这些类是JDK中javax.xml.parses包下的类，我们学习解析xml的时候已经使用过了，这里就不再往里面跑了。这样配置文件的读取工作就搞定了，接下来的就是解析配置文件了。

方法调用的序列图