如果没有依赖spring，可以将分割线下的方法去掉

import org.springframework.core.io.ClassPathResource;import org.springframework.core.io.Resource;import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import org.springframework.util.ResourceUtils;import java.io.*;import java.net.URL;import java.net.URLConnection;import java.nio.charset.Charset;import java.util.Properties;public class Resources {    private static ClassLoaderWrapper classLoaderWrapper = new ClassLoaderWrapper();    private static Charset charset;    Resources() {    }    public static ClassLoader getDefaultClassLoader() {        return classLoaderWrapper.defaultClassLoader;    }    public static void setDefaultClassLoader(ClassLoader defaultClassLoader) {        classLoaderWrapper.defaultClassLoader = defaultClassLoader;    }    public static URL getResourceURL(String resource) throws IOException {        return getResourceURL((ClassLoader)null, resource);    }    public static URL getResourceURL(ClassLoader loader, String resource) throws IOException {        URL url = classLoaderWrapper.getResourceAsURL(resource, loader);        if(url == null) {            throw new IOException("Could not find resource " + resource);        } else {            return url;        }    }    public static InputStream getResourceAsStream(String resource) throws IOException {        return getResourceAsStream((ClassLoader)null, resource);    }    public static InputStream getResourceAsStream(Class
      clazz, String resource) throws IOException {        InputStream in = classLoaderWrapper.getResourceAsStream(resource, clazz);        if(in == null) {            throw new IOException("Could not find resource " + resource);        } else {            return in;        }    }    public static InputStream getResourceAsStream(ClassLoader loader, String resource) throws IOException {        InputStream in = classLoaderWrapper.getResourceAsStream(resource, loader);        if(in == null) {            throw new IOException("Could not find resource " + resource);        } else {            return in;        }    }    public static Properties getResourceAsProperties(String resource) throws IOException {        Properties props = new Properties();        InputStream in = getResourceAsStream(resource);        props.load(in);        in.close();        return props;    }    public static Properties getResourceAsProperties(ClassLoader loader, String resource) throws IOException {        Properties props = new Properties();        InputStream in = getResourceAsStream(loader, resource);        props.load(in);        in.close();        return props;    }    public static Reader getResourceAsReader(String resource) throws IOException {        InputStreamReader reader;        if(charset == null) {            reader = new InputStreamReader(getResourceAsStream(resource));        } else {            reader = new InputStreamReader(getResourceAsStream(resource), charset);        }        return reader;    }    public static Reader getResourceAsReader(ClassLoader loader, String resource) throws IOException {        InputStreamReader reader;        if(charset == null) {            reader = new InputStreamReader(getResourceAsStream(loader, resource));        } else {            reader = new InputStreamReader(getResourceAsStream(loader, resource), charset);        }        return reader;    }    public static File getResourceAsFile(String resource) throws IOException {        return new File(getResourceURL(resource).getFile());    }    public static File getResourceAsFile(ClassLoader loader, String resource) throws IOException {        return new File(getResourceURL(loader, resource).getFile());    }    public static InputStream getUrlAsStream(String urlString) throws IOException {        URL url = new URL(urlString);        URLConnection conn = url.openConnection();        return conn.getInputStream();    }    public static Reader getUrlAsReader(String urlString) throws IOException {        InputStreamReader reader;        if(charset == null) {            reader = new InputStreamReader(getUrlAsStream(urlString));        } else {            reader = new InputStreamReader(getUrlAsStream(urlString), charset);        }        return reader;    }    public static Properties getUrlAsProperties(String urlString) throws IOException {        Properties props = new Properties();        InputStream in = getUrlAsStream(urlString);        props.load(in);        in.close();        return props;    }    public static Class
      classForName(String className) throws ClassNotFoundException {        return classLoaderWrapper.classForName(className);    }    public static Charset getCharset() {        return charset;    }    public static void setCharset(Charset charset) {        charset = charset;    }//############################ 华丽分割线 通过 spring 工具类 #################################    public static File getFileWithResourceUtils(String resource) throws FileNotFoundException {        return ResourceUtils.getFile(resource);    }    public Resource getResourceWithPathMatchingResourcePatternResolver(String resource) {        PathMatchingResourcePatternResolver pathMatchingResourcePatternResolver = new PathMatchingResourcePatternResolver();        return pathMatchingResourcePatternResolver.getResource(resource);    }    public Resource[] getResourcesWithPathMatchingResourcePatternResolver(String resource) throws IOException {        PathMatchingResourcePatternResolver pathMatchingResourcePatternResolver = new PathMatchingResourcePatternResolver();        return pathMatchingResourcePatternResolver.getResources(resource);    }    public InputStream getInputStreamWithClassPathResource(String resource, Class
      clazz) throws IOException {        if (clazz != null) {            return new ClassPathResource(resource, clazz).getInputStream();        } else {            return new ClassPathResource(resource).getInputStream();        }    }}class ClassLoaderWrapper {    ClassLoader defaultClassLoader;    ClassLoader systemClassLoader;    ClassLoaderWrapper() {        try {            this.systemClassLoader = ClassLoader.getSystemClassLoader();        } catch (SecurityException var2) {            ;        }    }    public URL getResourceAsURL(String resource) {        return this.getResourceAsURL(resource, this.getClassLoaders((ClassLoader)null));    }    public URL getResourceAsURL(String resource, ClassLoader classLoader) {        return this.getResourceAsURL(resource, this.getClassLoaders(classLoader));    }    public InputStream getResourceAsStream(String resource) {        return this.getResourceAsStream(resource, this.getClassLoaders((ClassLoader)null));    }    public InputStream getResourceAsStream(String resource, ClassLoader classLoader) {        return this.getResourceAsStream(resource, this.getClassLoaders(classLoader));    }    public Class
      classForName(String name) throws ClassNotFoundException {        return this.classForName(name, this.getClassLoaders((ClassLoader)null));    }    public Class
      classForName(String name, ClassLoader classLoader) throws ClassNotFoundException {        return this.classForName(name, this.getClassLoaders(classLoader));    }    InputStream getResourceAsStream(String resource, ClassLoader[] classLoader) {        ClassLoader[] arr$ = classLoader;        int len$ = classLoader.length;        for(int i$ = 0; i$ < len$; ++i$) {            ClassLoader cl = arr$[i$];            if(null != cl) {                InputStream returnValue = cl.getResourceAsStream(resource);                if(null == returnValue) {                    returnValue = cl.getResourceAsStream("/" + resource);                }                if(null != returnValue) {                    return returnValue;                }            }        }        return null;    }    URL getResourceAsURL(String resource, ClassLoader[] classLoader) {        ClassLoader[] arr$ = classLoader;        int len$ = classLoader.length;        for(int i$ = 0; i$ < len$; ++i$) {            ClassLoader cl = arr$[i$];            if(null != cl) {                URL url = cl.getResource(resource);                if(null == url) {                    url = cl.getResource("/" + resource);                }                if(null != url) {                    return url;                }            }        }        return null;    }    Class
      classForName(String name, ClassLoader[] classLoader) throws ClassNotFoundException {        ClassLoader[] arr$ = classLoader;        int len$ = classLoader.length;        for(int i$ = 0; i$ < len$; ++i$) {            ClassLoader cl = arr$[i$];            if(null != cl) {                try {                    Class
      c = Class.forName(name, true, cl);                    if(null != c) {                        return c;                    }                } catch (ClassNotFoundException var8) {                    ;                }            }        }        throw new ClassNotFoundException("Cannot find class: " + name);    }    ClassLoader[] getClassLoaders(ClassLoader classLoader) {        return new ClassLoader[]{classLoader, this.defaultClassLoader, Thread.currentThread().getContextClassLoader(), this.getClass().getClassLoader(), this.systemClassLoader};    }    public InputStream getResourceAsStream(String resource, Class
      clazz) {        return clazz.getResourceAsStream(resource);    }}

测试方法

try {    File file = ResourceUtils.getFile("classpath:" + Resources.class.getName().replace(".", "/") + ".class");    BufferedReader br = new BufferedReader(new FileReader(file));    String str = null;    while ((str = br.readLine()) != null) {        System.out.println(str);    }} catch (FileNotFoundException e) {    e.printStackTrace();} catch (IOException e) {    e.printStackTrace();}try {    PathMatchingResourcePatternResolver p = new PathMatchingResourcePatternResolver();    BufferedReader br = new BufferedReader(new InputStreamReader(p.getResource(Resources.class.getName().replace(".", "/") + ".class").getInputStream()));    String str = null;    while ((str = br.readLine()) != null) {        System.out.println(str);    }} catch (IOException e) {    e.printStackTrace();} //classpath 加不加都可以呦

try { PathMatchingResourcePatternResolver p = new PathMatchingResourcePatternResolver(); BufferedReader br = new BufferedReader(new InputStreamReader(p.getResources("classpath:"+Resources.class.getName().replace(".", "/") + ".class")[0].getInputStream())); String str = null; while ((str = br.readLine()) != null) { System.out.println(str); } } catch (IOException e) { e.printStackTrace(); } try { BufferedReader br = new BufferedReader(new InputStreamReader(Resources.getResourceAsStream(Resources.class.getName().replace(".", "/") + ".class"))); String str = null; while ((str = br.readLine()) != null) { System.out.println(str); } } catch (IOException e) { e.printStackTrace(); } try { BufferedReader br = new BufferedReader(new InputStreamReader(Resources.getResourceAsStream(Resources.class,"Resources.class"))); String str = null; while ((str = br.readLine()) != null) { System.out.println(str); } } catch (IOException e) { e.printStackTrace(); } try { BufferedReader br = new BufferedReader(new InputStreamReader(new ClassPathResource(Resources.class.getName().replace(".", "/") + ".class").getInputStream())); String str = null; while ((str = br.readLine()) != null) { System.out.println(str); } } catch (IOException e) { e.printStackTrace(); } try { BufferedReader br = new BufferedReader(new InputStreamReader(new ClassPathResource("Resources.class", Resources.class).getInputStream())); String str = null; while ((str = br.readLine()) != null) { System.out.println(str); } } catch (IOException e) { e.printStackTrace(); } try { BufferedReader br = new BufferedReader(new InputStreamReader(Resources.getResourceAsStream(Resources.class.getName().replace(".", "/") + ".class"))); String str = null; while ((str = br.readLine()) != null) { System.out.println(str); } } catch (IOException e) { e.printStackTrace(); }

 

可以获取到多个，包括我们自己定义的Resources.class

try {    PathMatchingResourcePatternResolver p = new PathMatchingResourcePatternResolver();    BufferedReader br = new BufferedReader(new InputStreamReader(p.getResources("classpath*:com/**/Resources.class")[0].getInputStream()));    String str = null;    while ((str = br.readLine()) != null) {        System.out.println(str);    }} catch (IOException e) {    e.printStackTrace();}

不可以获取到

try {    PathMatchingResourcePatternResolver p = new PathMatchingResourcePatternResolver();    BufferedReader br = new BufferedReader(new InputStreamReader(p.getResources("classpath:com/**/Resources.class")[0].getInputStream()));    String str = null;    while ((str = br.readLine()) != null) {        System.out.println(str);    }} catch (IOException e) {    e.printStackTrace();}

原因看一下 方法的源代码就发现了哦！

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.indexOf(":") + 1;        return this.getPathMatcher().isPattern(locationPattern.substring(prefixEnd))?this.findPathMatchingResources(locationPattern):new Resource[]{this.getResourceLoader().getResource(locationPattern)};    }}

　　findPathMatchingResources方法中调用getResources 最后执行的 代码中标红色的部分，通过resourceLoader返回资源。

　　classpath*: 和 classpath: 不同的地方看一下getResources方法中 代码中标红色的 部分。