// 完成初始化和认证 confLoad(); authentication(); // 创建一个用例 HdfsExample hdfs_examples = new HdfsExample("/user/hdfs-examples", "test.txt"); /**  *   * 如果程序运行在Linux上，则需要core-site.xml、hdfs-site.xml的路径修改  * 为在Linux下客户端文件的绝对路径  *  *   */   private static void confLoad() throws IOException {   conf = new Configuration();   // conf file   conf.addResource(new Path(PATH_TO_HDFS_SITE_XML));   conf.addResource(new Path(PATH_TO_CORE_SITE_XML));   // conf.addResource(new Path(PATH_TO_SMALL_SITE_XML)); } /**  *安全认证  *  */ private static void authentication() throws IOException {   // security mode   if ("kerberos".equalsIgnoreCase(conf.get("hadoop.security.authentication"))) {     System.setProperty("java.security.krb5.conf", PATH_TO_KRB5_CONF);     LoginUtil.login(PRNCIPAL_NAME, PATH_TO_KEYTAB, PATH_TO_KRB5_CONF, conf);   } } /**  *创建用例  */ public HdfsExample(String path, String fileName) throws IOException  {   this.DEST_PATH = path;   this.FILE_NAME = fileName;   instanceBuild(); } private void instanceBuild() throws IOException {   fSystem = FileSystem.get(conf); }