首页 > 技术文章 > Android 通过Base64上传图片到服务器

zhujiabin 2016-12-12 16:46 原文

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!

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