下面，我以修改某一文件的权限为777为例：

 /** 执行Linux命令，并返回执行结果。 */
       public static String exec(String[] args) {
           String result = "";
           ProcessBuilder processBuilder = new ProcessBuilder(args);
           Process process = null;
           InputStream errIs = null;
           InputStream inIs = null;
           try {
               ByteArrayOutputStream baos = new ByteArrayOutputStream();
               int read = -1;
               process = processBuilder.start();
               errIs = process.getErrorStream();
               while ((read = errIs.read()) != -1) {
                   baos.write(read);
               }
               baos.write('\n');
               inIs = process.getInputStream();
               while ((read = inIs.read()) != -1) {
                   baos.write(read);
               }
               byte[] data = baos.toByteArray();
               result = new String(data);
           } catch (IOException e) {
               e.printStackTrace();
           } catch (Exception e) {
               e.printStackTrace();
           } finally {
               try {
                   if (errIs != null) {
                       errIs.close();
                   }
                   if (inIs != null) {
                       inIs.close();
                   }
               } catch (IOException e) {
                   e.printStackTrace();
               }
               if (process != null) {
                   process.destroy();
               }
           }
           return result;
       }

      String[] args = { "chmod", "777", "(文件路径)"};
       exec(args);