Java中Base64和File之间互转代码示例

public File base64ToFile(String base64, String filePath) {
        File file = new File(filePath);
        byte[] buffer;
        try {
            BASE64Decoder base64Decoder = new BASE64Decoder();
            buffer = base64Decoder.decodeBuffer(base64);
            FileOutputStream out = new FileOutputStream(filePath);
            out.write(buffer);
            out.close();
        } catch (Exception e) {
            Log.e("TAG", "异常信息:" + e.getMessage());
        }
        return file;
    }

public String fileToBase64(String filePath) {
	File file = new File(filePath);
	FileInputStream inputFile;
	try {
		inputFile = new FileInputStream(file);
		byte[] buffer = new byte[inputFile.available()];
		inputFile.read(buffer);
		inputFile.close();
		BASE64Encoder base64Encoder = new BASE64Encoder();
		Log.i("encodeFileToBase64", "encode = " + base64Encoder.encode(buffer));
		return base64Encoder.encode(buffer);
	} catch (Exception e) {
		Log.e("TAG", "异常信息:" + e.getMessage());
	}
	return "";
}

public File getFileFromBase64(String base) throws Exception {
        String base64Pic = base;
        File file = null;
        Map<String, Object> resultMap = new HashMap<String, Object>();
        if (base64Pic == null) { // 图像数据为空
            resultMap.put("resultCode", 0);
            resultMap.put("msg", "图片为空");
        } else {
            BASE64Decoder decoder = new BASE64Decoder();
            String baseValue = base64Pic.replaceAll(" ", "+");//前台在用Ajax传base64值的时候会把base64中的+换成空格，所以需要替换回来。
            byte[] b = decoder.decodeBuffer(baseValue.replace("data:image/jpeg;base64,", ""));//去除base64中无用的部分
            base64Pic = base64Pic.replace("base64,", "");
            SimpleDateFormat df2 = new SimpleDateFormat("yyyy-MM-dd");
            String nowDate = df2.format(new Date());
            String imgFilePath = QMConfig.filePathRoot + "\\" + nowDate + "\\" + System.currentTimeMillis();
            File file1 = new File(imgFilePath);
            if (!file1.exists() && !file1.isDirectory()) {//判断文件路径下的文件夹是否存在，不存在则创建
                file1.mkdirs();
            }
            try {
                for (int i = 0; i < b.length; ++i) {
                    if (b[i] < 0) {// 调整异常数据
                        b[i] += 256;
                    }
                }
                file = new File(imgFilePath + "\\" + System.currentTimeMillis());
                // 如果要返回file文件这边return就可以了,存到临时文件中
                OutputStream out = new FileOutputStream(file.getPath());
                out.write(b);
                out.flush();
                out.close();
            } catch (Exception e) {
                resultMap.put("resultCode", 0);
                resultMap.put("msg", "存储异常");
            }
        }
        return file;
    }