Retrofit 2文件下载/上传 [英] Retrofit 2 file down/upload
问题描述
我正在尝试使用改装2来下载/上传文件，但无法找到任何有关如何执行此操作的教程示例。
我的下载代码是：
I'm trying to down/upload a file with retrofit 2 but can't find any tutorials examples on how to do so. My code for downloading is:
@GET("documents/checkout")
public Call<File> checkout(@Query(value = "documentUrl") String documentUrl, @Query(value = "accessToken") String accessToken, @Query(value = "readOnly") boolean readOnly);
和
Call<File> call = RetrofitSingleton.getInstance(serverAddress)
.checkout(document.getContentUrl(), apiToken, readOnly[i]);
call.enqueue(new Callback<File>() {
@Override
public void onResponse(Response<File> response,
Retrofit retrofit) {
String fileName = document.getFileName();
try {
System.out.println(response.body());
long fileLength = response.body().length();
InputStream input = new FileInputStream(response.body());
File path = Environment.getExternalStorageDirectory();
File file = new File(path, fileName);
BufferedOutputStream output = new BufferedOutputStream(
new FileOutputStream(file));
byte data[] = new byte[1024];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
total += count;
output.write(data, 0, count);
}
output.flush();
output.close();
} catch (IOException e) {
String logTag = "TEMPTAG";
Log.e(logTag, "Error while writing file!");
Log.e(logTag, e.toString());
}
}
@Override
public void onFailure(Throwable t) {
// TODO: Error handling
System.out.println(t.toString());
}
});
我尝试过Call和Call，但似乎没有任何效果。
I've tried with Call and Call but nothing seems to work.
服务器端代码将文件的字节写入到HttpServletResponse的输出流中，正确设置了标题和MIME类型。
The server-side code writes the file's bytes into HttpServletResponse's output stream after setting the headers and mime type correctly.
我做错了什么？
最后，上传代码：
@Multipart
@POST("documents/checkin")
public Call<String> checkin(@Query(value = "documentId") String documentId, @Query(value = "name") String fileName, @Query(value = "accessToken") String accessToken, @Part("file") RequestBody file);
和
RequestBody requestBody = RequestBody.create(MediaType.parse(document.getMimeType()), file);
Call<String> call = RetrofitSingleton.getInstance(serverAddress).checkin(documentId, document.getFileName(), apiToken, requestBody);
call.enqueue(new Callback<String>() {
@Override
public void onResponse(Response<String> response, Retrofit retrofit) {
System.out.println(response.body());
}
@Override
public void onFailure(Throwable t) {
System.out.println(t.toString());
}
});
谢谢！
编辑：
答案后，下载只会产生一个损坏的文件（没有@Streaming），上传也不尽如人意。当我使用上面的代码，服务器返回一个400错误。更改为
After the answer, downloading only yields a corrupted file (without the @Streaming), uploading doesn't as well. When I use the above code, the server returns a 400 error. After changing it to
RequestBody requestBody = RequestBody.create(MediaType.parse(document.getMimeType()), file);
MultipartBuilder multipartBuilder = new MultipartBuilder();
multipartBuilder.addFormDataPart("file", document.getFileName(), requestBody);
Call<String> call = RetrofitSingleton.getInstance(serverAddress).checkin(documentId, document.getFileName(), apiToken, multipartBuilder.build());
，请求执行，但后端似乎没有收到文件。
, the request executes but the backend doesn't seem to receive a file.
后端代码：
@RequestMapping(value = "/documents/checkin", method = RequestMethod.POST)
public void checkInDocument(@RequestParam String documentId,
@RequestParam String name, @RequestParam MultipartFile file,
@RequestParam String accessToken, HttpServletResponse response)
我做错了什么？我能够使用Apache HttpClient的简单Java后端：
What am I doing wrong? I was able to use the backend from plain Java with the Apache HttpClient:
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
builder.addBinaryBody("file", new File("E:\\temp\\test.jpg"));
HttpEntity httpEntity = builder.build();
System.out.println("HttpEntity " + EntityUtils.toString(httpEntity.));
HttpPost httpPost = new HttpPost(uri);
httpPost.setEntity(httpEntity);
编辑v2
对于任何有兴趣的人，现在都可以上传和下载工作：这些是解决方案：
For anyone interested, both up- and downloading work now: These are the solutions:
服务：
@GET("documents/checkout")
public Call<ResponseBody> checkout(@Query(value = "documentUrl") String documentUrl, @Query(value = "accessToken") String accessToken, @Query(value = "readOnly") boolean readOnly);
@Multipart
@POST("documents/checkin")
public Call<String> checkin(@Query(value = "documentId") String documentId, @Query(value = "name") String fileName, @Query(value = "accessToken") String accessToken, @Part("file") RequestBody file);
下载代码：
Call<ResponseBody> call = RetrofitSingleton.getInstance(serverAddress)
.checkout(document.getContentUrl(), apiToken, readOnly[i]);
call.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Response<ResponseBody> response,
Retrofit retrofit) {
String fileName = document.getFileName();
try {
File path = Environment.getExternalStorageDirectory();
File file = new File(path, fileName);
FileOutputStream fileOutputStream = new FileOutputStream(file);
IOUtils.write(response.body().bytes(), fileOutputStream);
} catch (IOException e) {
Log.e(logTag, "Error while writing file!");
Log.e(logTag, e.toString());
}
}
@Override
public void onFailure(Throwable t) {
// TODO: Error handling
System.out.println(t.toString());
}
});
上传代码：
Call<String> call = RetrofitSingleton
.getInstance(serverAddress).checkin(documentId,
document.getFileName(), apiToken,
multipartBuilder.build());
call.enqueue(new Callback<String>() {
@Override
public void onResponse(Response<String> response,
Retrofit retrofit) {
// Handle response here
}
@Override
public void onFailure(Throwable t) {
// TODO: Error handling
System.out.println("Error");
System.out.println(t.toString());
}
});
推荐答案
下载时，您可以使用 ResponseBody 作为您的返回类型 -
For downloading, you can use ResponseBody as your return type --
@GET("documents/checkout")
@Streaming
public Call<ResponseBody> checkout(@Query("documentUrl") String documentUrl, @Query("accessToken") String accessToken, @Query("readOnly") boolean readOnly);
，您可以获得 ResponseBody 输入流在您的回电中 -
and you can get the ResponseBody input stream in your call back --
Call<ResponseBody> call = RetrofitSingleton.getInstance(serverAddress)
.checkout(document.getContentUrl(), apiToken, readOnly[i]);
call.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Response<ResponseBody> response,
Retrofit retrofit) {
String fileName = document.getFileName();
try {
InputStream input = response.body().byteStream();
// rest of your code
如果您的服务器正确处理多部分消息，您的上传情况乍看起来是否正常？如果不行，是否可以解释失败模式？您也可以通过不使其多部分来简化。删除 @Multipart 注释并转换 @Path 到 @Body -
Your upload looks okay at first glance if you server handles multipart messages correctly. Is it working? If not, can you explain the failure mode? You also might be able to simplify by not making it multipart. Remove the @Multipart annotation and convert @Path to @Body --
@POST("documents/checkin")
public Call<String> checkin(@Query("documentId") String documentId, @Query("name") String fileName, @Query("accessToken") String accessToken, @Body RequestBody file);
这篇关于Retrofit 2文件下载/上传的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
