PathMatchingResourcePatternResolver

核心方法源码：

public Resource[] getResources(String locationPattern) throws IOException {
    Assert.notNull(locationPattern, "Location pattern must not be null");
    if (locationPattern.startsWith("classpath*:")) {
        return this.getPathMatcher().isPattern(locationPattern.substring("classpath*:".length())) ? this.findPathMatchingResources(locationPattern) : this.findAllClassPathResources(locationPattern.substring("classpath*:".length()));
    } else {
        int prefixEnd = locationPattern.startsWith("war:") ? locationPattern.indexOf("*/") + 1 : locationPattern.indexOf(58) + 1;
        return this.getPathMatcher().isPattern(locationPattern.substring(prefixEnd)) ? this.findPathMatchingResources(locationPattern) : new Resource[]{this.getResourceLoader().getResource(locationPattern)};
    }
}

源码解析：

1.判断参数是否以classpath*:作为前缀

    是，判断截断参数后是否还有*，？通配符

        是，进入findPathMatchigResources方法

        否，进入findAllClassPathResources方法

    否，判断截断参数后是否还有*，？通配符

        是，进入findPathMatchigResources方法

        否，进入无通配符的获取资源方法

2.解析findAllClassPathResources---通过类加载器获取类路径下的资源

protected Resource[] findAllClassPathResources(String location) throws IOException {
    String path = location;
    if (location.startsWith("/")) {
        path = location.substring(1);
    }

    Set<Resource> result = this.doFindAllClassPathResources(path);
    if (logger.isDebugEnabled()) {
        logger.debug("Resolved classpath location [" + location + "] to resources " + result);
    }

    return (Resource[])result.toArray(new Resource[0]);
}

进一步查看doFindAllClassPathResources

protected Set<Resource> doFindAllClassPathResources(String path) throws IOException {
    Set<Resource> result = new LinkedHashSet(16);
    ClassLoader cl = this.getClassLoader();
    Enumeration resourceUrls = cl != null ? cl.getResources(path) : ClassLoader.getSystemResources(path);

    while(resourceUrls.hasMoreElements()) {
        URL url = (URL)resourceUrls.nextElement();
        result.add(this.convertClassLoaderURL(url));
    }

    if ("".equals(path)) {
        this.addAllClassLoaderJarRoots(cl, result);
    }

    return result;
}

2.解析findPathMatchingResources

protected Resource[] findPathMatchingResources(String locationPattern) throws IOException {
    String rootDirPath = this.determineRootDir(locationPattern);
    String subPattern = locationPattern.substring(rootDirPath.length());
    Resource[] rootDirResources = this.getResources(rootDirPath);
    Set<Resource> result = new LinkedHashSet(16);
    Resource[] var6 = rootDirResources;
    int var7 = rootDirResources.length;

    for(int var8 = 0; var8 < var7; ++var8) {
        Resource rootDirResource = var6[var8];
        Resource rootDirResource = this.resolveRootDirResource(rootDirResource);
        URL rootDirUrl = ((Resource)rootDirResource).getURL();
        if (equinoxResolveMethod != null && rootDirUrl.getProtocol().startsWith("bundle")) {
            URL resolvedUrl = (URL)ReflectionUtils.invokeMethod(equinoxResolveMethod, (Object)null, new Object[]{rootDirUrl});
            if (resolvedUrl != null) {
                rootDirUrl = resolvedUrl;
            }

            rootDirResource = new UrlResource(rootDirUrl);
        }

        if (rootDirUrl.getProtocol().startsWith("vfs")) {
            result.addAll(PathMatchingResourcePatternResolver.VfsResourceMatchingDelegate.findMatchingResources(rootDirUrl, subPattern, this.getPathMatcher()));
        } else if (!ResourceUtils.isJarURL(rootDirUrl) && !this.isJarResource((Resource)rootDirResource)) {
            result.addAll(this.doFindPathMatchingFileResources((Resource)rootDirResource, subPattern));
        } else {
            result.addAll(this.doFindPathMatchingJarResources((Resource)rootDirResource, rootDirUrl, subPattern));
        }
    }

    if (logger.isDebugEnabled()) {
        logger.debug("Resolved location pattern [" + locationPattern + "] to resources " + result);
    }

    return (Resource[])result.toArray(new Resource[0]);
}

分析：首先获取路径不含通配符的目录下所有资源，然后遍历所有资源进行匹配

3.不以classpath*开头，且并不包含通配符，进入DefaultResourceLoader().getResource()