Java读取文件转为字符串

/**
     * 读取文件中的内容
     * @param file
     * @return string
     */
    private String parseFile2String(MultipartFile file){
        if(file.isEmpty()){
            return "";
        }
        BufferedReader reader = null;
        StringBuffer buffer = new StringBuffer();
        try {
            reader = new BufferedReader(new InputStreamReader(file.getInputStream()));
            String line = reader.readLine();
            while (StringUtils.hasLength(line)) {
                buffer.append(line);
                buffer.append("\n");
                line = reader.readLine();
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(reader != null){
                try {
                    reader.close();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }

        }
        return buffer.toString();
    }