android自更新时下载出现的问题-阿里云开发者社区

android自更新时下载出现的问题

2016-05-10 1387

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简介：

之前做过一个电视台app,电视台app每次启动时会访问服务器,判断是否需要下载新版本

但是下载时老是下载失败,apk包总是下载不下来.到底是什么原因呢?

服务器下载接口如下:

   Java代码  
    
  
/*** 
     * 下载apk 
     * @param path 
     * @param request 
     * @return 
     * @throws IOException 
     */  
    @RequestMapping(value = "/download"/*, headers = {"content-type=application/json"}*/)  
    public ResponseEntity<byte[]> download( String path,HttpServletRequest request) throws IOException {  
        AccessLog accessLog=logInto(request);  
        accessLog.setDescription("下载客户端");  
        if(!ValueWidget.isNullOrEmpty(request.getContentType())&& request.getContentType().toLowerCase().contains("application/json")){  
            String requestStr=WebServletUtil.getRequestQueryStr(request, null);  
            System.out.println(requestStr);  
            Map queryMap=JSONPUtil.getMapFromJson(requestStr);  
            if(!ValueWidget.isNullOrEmpty(queryMap)){  
                path=(String) queryMap.get("path");  
            }  
        }  
        if(ValueWidget.isNullOrEmpty(path)){  
            System.out.println("download failed");  
            accessLog.setOperateResult("下载失败,没有传递path参数");  
            logSave(accessLog, request);  
            return null;  
        }  
        String realpath =WebServletUtil.getUploadPath(request, "upload/download/apk", request  
                .getSession().getServletContext(), Constant2.SRC_MAIN_WEBAPP);  
        if(!realpath.endsWith(File.separator)){  
            realpath=realpath+File.separator;  
        }  
        HttpHeaders headers = new HttpHeaders();  
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);  
        String fullpath=realpath+path;  
          
        System.out.println("download path:"+fullpath);  
        headers.set(Constant2.CONTENT_DISPOSITION,WebServletUtil.getContentDisposition(true, path));  
        accessLog.setOperateResult("下载成功,下载文件:"+fullpath+" ,size:"+FileUtils.getFileSize2(fullpath));  
        logSave(accessLog, request);  
        return new ResponseEntity<byte[]>(FileUtils.getBytes4File(fullpath),  
                                          headers, HttpStatus.CREATED);  
    }  

安卓端调用的下载方法(核心代码)如下:

   Java代码  
    
  
/*** 
     *  
     * @param huc 
     * @param sendBytes 
     * @param mode 
     * @param isWrite2file 
     *            : 是否写入文件 
     * @return 
     * @throws Exception 
     */  
    private static byte[] connection(HttpURLConnection huc,  
            boolean isWrite2file, Object file, String sizeHeadKey)  
            throws Exception {  
        int resCode = huc.getResponseCode();  
  
        if (resCode == HttpURLConnection.HTTP_OK) {  
            int contentLength = 0;  
            if (ValueWidget.isNullOrEmpty(sizeHeadKey)) {// 若header中没有size  
                contentLength = huc.getContentLength();  
            } else {  
                String sizeHeaderValue = huc.getHeaderField(sizeHeadKey);  
                if (!ValueWidget.isNullOrEmpty(sizeHeaderValue)) {  
                    contentLength = Integer.parseInt(sizeHeaderValue);  
                }  
  
            }  
            if (isDetail) {  
                System.out  
                        .println("[connection]contentLength:" + contentLength);  
                responseHeaderFields = huc.getHeaderFields();  
                String downloadHeader = "Content-Disposition";  
                if (!ValueWidget.isNullOrEmpty(responseHeaderFields)) {  
                    List<String> ContentDispositions = responseHeaderFields  
                            .get(downloadHeader);  
                    if (!ValueWidget.isNullOrEmpty(ContentDispositions)) {  
                        String ContentDisposition = ContentDispositions.get(0);  
                        System.out.println("ContentDisposition:"  
                                + ContentDisposition);  
                        System.out.println("ContentDisposition convertISO2UTF:"  
                                + SystemHWUtil  
                                        .convertISO2UTF(ContentDisposition));  
                        System.out  
                                .println("ContentDisposition convertISO2GBK: "  
                                        + SystemHWUtil  
                                                .convertISO2GBK(ContentDisposition));  
                    }  
                }  
                for (Object obj : responseHeaderFields.keySet()) {  
                    List<String> list = responseHeaderFields.get(obj);  
                    if (!ValueWidget.isNullOrEmpty(list)) {  
                        System.out.println(obj + " : "  
                                + SystemHWUtil.formatArr(list, ";"));  
                    }  
                }  
                System.out  
                        .println("[connection]contentLength:" + contentLength);  
            }  
            if (contentLength > 0) {  
                if (isDetail)  
                    System.out  
                            .println("[HttpSocketUtil.connection]httputil,contentLength:"  
                                    + contentLength);  
                // return readData(huc);  
                File file2 = null;  
                if (isWrite2file) {  
                    if (file instanceof File) {  
                        file2 = (File) file;  
                        writeFileFromLength(huc, contentLength, file2);  
                        if (isDetail) {  
                            System.out.println("download success:"  
                                    + file2.getAbsolutePath());  
                        }  
                    } else {  
                        writeFileFromLength(huc, contentLength,  
                                (OutputStream) file);  
                    }  
                    return null;  
                } else {  
                    return readDataFromLength(huc, contentLength);  
                }  
            } else {  
                if (isWrite2file) {  
                    InputStream in = huc.getInputStream();  
                    FileUtils.writeIn2OutputCloseAll(in, new FileOutputStream(  
                            (File) file));  
                    if (isDetail) {  
                        System.out.println("download success:"  
                                + ((File) file).getAbsolutePath());  
                    }  
                    return null;  
                }  
                return readData(huc);  
            }  
        } else {  
            System.out.println("response Code:" + resCode);  
        }  
        return null;  
    }  

代码本身是没有逻辑错误的.花了很长时间才找到原因,是定义的response的status code不一致.

后台设置的status code是201,而Android端判断的status code是200,不一致导致下载流程没有走到下载逻辑.

修改方法:把后台的status code改为200 就OK了

android自更新时下载出现的问题

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