Android 通过Base64上传图片到服务器实现实例

Android 通过Base64上传图片到服务器

之前做上传图片是采用HttpServlet上传，不过用了一下Base64上传图片后，感觉比HttpServlet方便很多，大家也可以跟着尝试一下。

前台图片处理：（传Bitmap对象即可）

/**
 * 通过Base32将Bitmap转换成Base64字符串
 * @param bit
 * @return
 */
public String Bitmap2StrByBase64(Bitmap bit){
  ByteArrayOutputStream bos=new ByteArrayOutputStream();
  bit.compress(CompressFormat.JPEG, 40, bos);//参数100表示不压缩
  byte[] bytes=bos.toByteArray();
  return Base64.encodeToString(bytes, Base64.DEFAULT);
}

 前台发送数据：（調用setImgByStr()方法，第一個參數imgStr 为Bitmap转成Base64的字符串，第二个参数imgName为图片的名字，包含后缀名.jpg）

public static String host = "http://192.168.1.166:8080/ImageServer/"; 

public static String getContent(String url) throws Exception { 

  StringBuilder sb = new StringBuilder(); 

  HttpClient client = new DefaultHttpClient();
  HttpParams httpParams = client.getParams();
  // 设置网络超时参数
  HttpConnectionParams.setConnectionTimeout(httpParams, 3000); 

  HttpConnectionParams.setSoTimeout(httpParams, 5000);
  HttpResponse response = client.execute(new HttpGet(url));
  HttpEntity entity = response.getEntity();
  if (entity != null) {
    BufferedReader reader = new BufferedReader(new InputStreamReader(
        entity.getContent(), "UTF-8"), 8192); 

    String line = null;
    while ((line = reader.readLine()) != null) {
      sb.append(line + "\n");
    }
    reader.close(); 

  } 

  return sb.toString();
}
public static HttpResponse post(Map<String, Object> params, String url) { 

  HttpClient client = new DefaultHttpClient();
  HttpPost httpPost = new HttpPost(url);
  httpPost.addHeader("charset", HTTP.UTF_8);
  httpPost.setHeader("Content-Type",
      "application/x-www-form-urlencoded; charset=utf-8");
  HttpResponse response = null;
  if (params != null && params.size() > 0) {
    List<NameValuePair> nameValuepairs = new ArrayList<NameValuePair>();
    for (String key : params.keySet()) {
      nameValuepairs.add(new BasicNameValuePair(key, (String) params
          .get(key)));
    }
    try {
      httpPost.setEntity(new UrlEncodedFormEntity(nameValuepairs,
          HTTP.UTF_8));
      response = client.execute(httpPost);
    } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
    } catch (ClientProtocolException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } catch (RuntimeException e) {
      e.printStackTrace();
    }
  } else {
    try {
      response = client.execute(httpPost);
    } catch (ClientProtocolException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  } 

  return response; 

}
public static Object getValues(Map<String, Object> params, String url) {
  String token = "";
  HttpResponse response = post(params, url);
  if (response != null) {
    try {
      token = EntityUtils.toString(response.getEntity());
      response.removeHeaders("operator");
    } catch (ParseException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  return token;
}
public static Object setImgByStr(String imgStr,String imgName){
  String url = host+"channel-uploadImage.action";
  Map<String,Object> params = new HashMap<String, Object>();
  params.put("imgStr", imgStr);
  params.put("imgName", imgName);
  return getValues(params, url);
}

后台接收数据：

public void uploadPhoto() {
  //获取存储路径
  HttpServletRequest request = ServletActionContext.getRequest();
  String path = ServletActionContext.getServletContext().getRealPath("/")+"upload";
  File file = new File(path);
  if(!file.exists()){
    file.mkdir();
  }
  String imgPath = path + request.getParameter("imgName");
  String imgStr = request.getParameter("imgStr");
  boolean flag = string2Image(imgStr, imgPath);
  JacksonUtil.responseJSON(response, flag);
}

后台图片处理：

/**
 * 通过BASE64Decoder解码，并生成图片
 * @param imgStr 解码后的string
 */
public boolean string2Image(String imgStr, String imgFilePath) {
  // 对字节数组字符串进行Base64解码并生成图片
  if (imgStr == null)
    return false;
  try {
    // Base64解码
    byte[] b = new BASE64Decoder().decodeBuffer(imgStr);
    for (int i = 0; i < b.length; ++i) {
      if (b[i] < 0) {
        // 调整异常数据
        b[i] += 256;
      }
    }
    // 生成Jpeg图片
    OutputStream out = new FileOutputStream(imgFilePath);
    out.write(b);
    out.flush();
    out.close();
    return true;
  } catch (Exception e) {
    return false;
  }
}

OK ! 如果成功上传前端会接收到true ，反之失败false。希望对大家有所帮助！