我开发接受JSON
(包括链接到图片)的应用程序,然后通过这些链接,我得到响应的头和以写这些图片外部存储从那里拉出来contentlength()
和contenttype()
和source()
。
JSON例如:
[
{
"imageUrl": "https://bipbap.ru/wp-content/uploads/2018/01/57a741c2d70811566558e141.png"
},
{
"imageUrl": "https://bipbap.ru/wp-content/uploads/2018/01/57a741c2d70811566558e141.png"
},
{
"imageUrl": "https://bipbap.ru/wp-content/uploads/2018/01/57a741c2d70811566558e141.png"
},
{
"imageUrl": "https://bipbap.ru/wp-content/uploads/2018/01/57a741c2d70811566558e141.png"
}
]
代码示例:
public interface RetrofitApi {
@GET("bins/xdfi8")
Call<List<Image>> getImage();
@GET
Call<ResponseBody> getImage(@Url String url);
}
</code>
// main activity.Java
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.myjson.com/")
.addConverterFactory(GsonConverterFactory.create())
.build();
final RetrofitApi retrofitApi = retrofit.create(RetrofitApi.class);
Call<List<Image>> call = retrofitApi.getImages();
call.enqueue(new Callback<List<Image>>() {
@Override
public void onResponse(Call<List<Image>> call, Response<List<Image>> response) {
if (!response.isSuccessful()) {
textViewResult.setText("Code: " + response.code());
return;
}
List<Image> images = response.body();
for (Image image : images) {
Call<ResponseBody> responseBodyCall = retrofitApi.getResponseBody(image.getImageUrl());
responseBodyCall.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
String content = "";
content += response.body().contentType().subtype() + "\n";
content += response.body().contentLength() + "\n\n";
// for example print contenttype and contentlength in TextView
textViewResult.append(content);
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
}
});
@Override
public void onFailure(Call<List<Image>> call, Throwable t) {
}
});
}
}
image.Java
public class Image {
public String getImageUrl() {
return imageUrl;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
private String imageUrl;
}
目前,一个呼叫正在投入另一个电话,如何避免呢?
同样感兴趣的方法,如果我们使用RxJava
和RetrofitApi
会采取这种形式:
public interface RetrofitApi {
@GET("bins/xdfi8")
Observable<List<Image>> getImage();
@GET
Observable<Response<ResponseBody>> getImage(@Url String url);
}
比方说,你有这样的API:
public interface RetrofitApi {
@GET("bins/xdfi8")
Observable<List<Image>> getImage();
@GET
Observable<Response<ResponseBody>> getImage(@Url String url);
}
然后在活动:
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.myjson.com/")
.addConverterFactory(GsonConverterFactory.create())
.build();
final RetrofitApi retrofitApi = retrofit.create(RetrofitApi.class);
retrofitApi.getImages() // Observable<List<Image>>
.flatMapIterable(images -> images) // Observable<Image>
.flatMap(image -> retrofitApi.getImage(image.getImageUrl()))
.onErrorResumeNext(Observable.empty())) // Observable<ResponseBody>
.subscribeOn(Schedulers.io()) // run using io scheduler
.observeOn(AndroidSchedulers.mainThread()) // observe in main thread
.subscribe(result -> {
...
textViewResult.append(content);
}, error -> {
textViewResult.setText("Code: " + error);
})