Retrofit 2 Download Adapter
A file download specialized call for Retrofit 2.
Usage
Basics
Use Download.Builder
as return type of the retrofit method, @Streaming
annotation is required.
interface Service {
@Streaming
@GET
Download.Builder download(@Url String url);
}
Add DownloadCallAdapterFactory
when setting up retrofit, and then create the service as usual.
Retrofit retrofit = new Retrofit.Builder()
...
.addCallAdapterFactory(DownloadCallAdapterFactory.create())
...
.build();
Service service = retrofit.create(Service.class);
Specify the destination file with .to
, a regular retrofit Call<ReponseBody>
will be returned. To start the download use .execute
or .enqueue
.
File myFile = ...
service.download(someUrl)
.to(myFile)
.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
...
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
...
}
});
Progress
Set a ProgressListener
to be notified of the download advancement.
service.download(someUrl)
.progress(new ProgressListener() {
@Override
public void onProgress(Download download, long bytesRead, long totalBytesRead, long contentLength) {
dialog.setProgress((int) (totalBytesRead * 100f / contentLength));
}
})
.to(...)
.enqueue(...)
Tag
Extra data can be stored with .tag
, it can be handy in some situations.
MyFilePojo myFilePojo = ...
service.download(someUrl)
.tag(myFilePojo)
.to(...)
.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
Download download = (Download) call;
MyFilePojo myFilePojo = (MyFilePojo) download.tag();
openFile(download.file(), myFilePojo.mimeType());
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
...
}
});
Validation
Validate the download when finished.
final String expectedChecksum = ...
service.download(someUrl)
.validate(Checksum.MD5, new ValidationCallback() {
@Override
public void validate(Download download, String checksum) throw IOException {
if (!expectedChecksum.equals(checksum)) {
throw new IOException("Invalid checksum");
}
}
})
.to(...)
.enqueue(...);
Filters
Stream can be modified before being written to the file with Filter
s.
service.download(someUrl)
.addFilter(new OutputStreamFilter() {
@Override
public OutputStream create(Download download, OutputStream downstream) throws IOException {
return new CipherOutputStream(downstream, new MyFancyCipher());
}
})
.to(...)
.enqueue(...);
Download
or maven
<dependency>
<groupId>com.github.samizerouta.retrofit</groupId>
<artifactId>retrofit2-download-adapter</artifactId>
<version>1.0.0</version>
</dependency>
or gradle
compile 'com.github.samizerouta.retrofit:retrofit2-download-adapter:1.0.0'
Snapshots of the development version are available in Sonatype's snapshots
repository.
License
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.