转自 http://blog.csdn.net/jian_csdn/article/details/46119313              ClassLoader classLoader = Thread.currentThread().getContextClassLoader();            if (classLoader == null) {                classLoader = ClassLoader.getSystemClassLoader();            }            /**             * 获取到webroot里面的数据             */            java.net.URL url2 = classLoader.getResource("");            String ROOT_CLASS_PATH = url2.getPath() + "/";            File rootFile = new File(ROOT_CLASS_PATH);            String WEB_INFO_DIRECTORY_PATH = rootFile.getParent() + "/";            File webInfoDir = new File(WEB_INFO_DIRECTORY_PATH);            String SERVLET_CONTEXT_PATH = webInfoDir.getParent() + "/";            // 这里 SERVLET_CONTEXT_PATH 就是WebRoot的路径            String path = SERVLET_CONTEXT_PATH + "/" + "file/db.txt";