finally中关闭资源

对finally中关闭资源是否还要使用try...catch老是感到迷惑，现在存个例子，省的忘了

 public StringBuilder readTxtFile(File file){
     StringBuilder sBuilder = new StringBuilder();
     InputStreamReader isr = null;
     BufferedReader br = null;
     try {
         if (file.isFile() && file.exists()) {
             isr = new InputStreamReader(new FileInputStream(file), "GBK");
             br = new BufferedReader(isr);
             String line = null;

             while ((line = br.readLine()) != null) {
                 System.out.println(line);
                 sBuilder.append(line);
             }
         } else {
             logger.info("文件不存在!");
         }
     } catch (Exception e) {
             logger.info("文件读取错误!");
     } finally {
         // 关闭流
         try {
             if(isr != null) {
                 isr.close();
                 logger.info("isr已经成功关闭!");
             }
             if(br != null){
                 br.close();
                 logger.info("br已经成功关闭!");
             }
         } catch(Exception e) {
             e.printStackTrace();
         }
     }
    return sBuilder;
37 }