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 }