文件读取为字符串

    public static String file2String(final File file) throws IOException {
        if (file.exists()) {
            byte[] data = new byte[(int) file.length()];
            boolean result;

            FileInputStream inputStream = null;
            try {
                inputStream = new FileInputStream(file);
                int len = inputStream.read(data);
                result = len == data.length;
            } finally {
                if (inputStream != null) {
                    inputStream.close();
                }
            }

            if (result) {
                return new String(data);
            }
        }
        return null;
    }