从服务器下载pdf文件时发出
从服务器下载pdf文件时发出
提问于 2017-11-08 05:26:05
我试图在webApi的帮助下读取retrofit.but的图像--不幸的是，每次调用都会调用onFailure。对于同样的问题，大多数人都把这个链接作为解决方案(https://futurestud.io/tutorials/retrofit-2-how-to-download-files-from-server).I已经尝试过了，但它不起作用)。
我的webApi代码：
[Route("api/GetPdf")]
public HttpResponseMessage GetPdf(string PdfName)
{
DataAccess objClsData = new DataAccess();
SqlDataReader _SqlReader;
_SqlReader = objClsData.ExecuteQuery("select VALUE FROM [Param] where subkey='imagepath'");
if (_SqlReader.HasRows)
{
if (_SqlReader.Read())
{
string FileName = WebUtility.UrlDecode(PdfName);
string PdfFile = _SqlReader["VALUE"].ToString() + "\\" + FileName + ".pdf";
//string PdfFile = _SqlReader["VALUE"].ToString() + "\\" + "bill##8000006" + ".pdf";
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
FileStream fileStream = File.OpenRead(PdfFile);
response.Content = new StreamContent(fileStream);
response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
return response;
}
}
HttpResponseMessage responseError = new HttpResponseMessage(HttpStatusCode.NotFound);
return responseError;
}我的Android webApi call:
@GET("GetPdf")
Call<ResponseBody> downloadFile(@Query("PdfName") String PdfName);我的安卓代码：
public class FileDownloadUtil {
private Activity mActivity;
private String mUrl;
private String subjectTitle;
private ProgressDialog dialog;
private Menu menu;
private boolean isCancelled = false;
public FileDownloadUtil(Activity context, String billNumber) {
this.mActivity = context;
this.mUrl = billNumber;
Utilities.getRetrofitWebService(context).downloadFile("mUrl").
enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Response<ResponseBody> response, Retrofit retrofit) {
if (response != null && response.body() != null) {
boolean isFileWriteToStorage = writeResponseBodyToDisk(response.body());
if (isFileWriteToStorage) {
Log.e("File stored", ">>");
String path = getFilePath();
if (path != null)
printFile(path);
} else {
Log.e("Failed to store ", ">");
Utilities.showSnackBar("Unable to Download File", mActivity);
}
}
}
@Override
public void onFailure(Throwable t) {
Log.e("Reason", "t" + t);
}
});
}
public void setSubjectTitle(String title) {
this.subjectTitle = title;
}
private void printFile(String filePath) {
PDFAsset pdfAsset4x6 = new PDFAsset(filePath, false);
PrintItem printItemDefault = new PDFPrintItem(PrintItem.ScaleType.CENTER, pdfAsset4x6);
PrintJobData printJobData = new PrintJobData(mActivity, printItemDefault);
printJobData.setJobName("Example");
PrintUtil.setPrintJobData(printJobData);
PrintUtil.print(mActivity);
}
private String getFilePath() {
String fileName = mUrl;
File mFile = fileExistence(fileName);
if (mFile.exists() && mFile.isFile()) {
return mFile.getPath();
}
return null;
}
private File fileExistence(String fName) {
return mActivity.getBaseContext().getFileStreamPath(fName);
}
private boolean writeResponseBodyToDisk(ResponseBody body) {
try {
//File downloadedFile = new File(getExternalFilesDir(null) + File.separator + "Future Studio Icon.png");
String fileName = mUrl;
File downloadedFile = new File(mActivity.getFilesDir(), fileName);
InputStream inputStream = null;
OutputStream outputStream = null;
try {
byte[] fileReader = new byte[4096];
long fileSize = body.contentLength();
long fileSizeDownloaded = 0;
inputStream = body.byteStream();
outputStream = new FileOutputStream(downloadedFile);
while (true) {
int read = inputStream.read(fileReader);
if (read == -1) {
break;
}
outputStream.write(fileReader, 0, read);
fileSizeDownloaded += read;
}
outputStream.flush();
return true;
} catch (IOException e) {
return false;
} finally {
if (inputStream != null) {
inputStream.close();
}
if (outputStream != null) {
outputStream.close();
}
}
} catch (IOException e) {
return false;
}
}
}错误我得到的是：
OnFailure:
java.lang.InstantiationException: Can't instantiate abstract class okhttp3.ResponseBody
Failed to invoke public okhttp3.ResponseBody() with no args(预先谢谢:)
回答 1
Stack Overflow用户
发布于 2017-11-08 05:39:01
声明您的下载方法如下
@GET
Call<ResponseBody> downloadFileWithDynamicUrlSync(@retrofit2.http.Url String fileUrl);下载文件的写入方法。
Retrofit retrofit = new Retrofit.Builder().baseUrl(main_url_first_part).addConverterFactory(GsonConverterFactory.create()).client(builder.build()).build();
UpdateService downloadService = retrofit.create(UpdateService.class);
Call<ResponseBody> call = downloadService.downloadFileWithDynamicUrlSync(NetworkConstants.SUB_URL);
call.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
}
});页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/47172136
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