如果沒有依賴spring，可以將分割線下的方法去掉

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;}//############################ 華麗分割線 通過 spring 工具類 #################################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);} }

測試方法

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(); }

?

可以獲取到多個，包括我們自己定義的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(); }

不可以獲取到

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 方法的源代碼就發現了哦！

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方法中調用getResources 最后執行的 代碼中標紅色的部分，通過resourceLoader返回資源。

　　classpath*: 和 classpath: 不同的地方看一下getResources方法中 代碼中標紅色的 部分。?

轉載于:https://www.cnblogs.com/hujunzheng/p/7219303.html

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