RxAndroid 和 Retrofit：无法为 io.reactivex.Observable<retrofit2.Response<okhttp3.ResponseBody>> 创建调用适配器
RxAndroid and Retrofit: Unable to create call adapter for io.reactivex.Observable<retrofit2.Response<okhttp3.ResponseBody>>
我正在尝试使用 rxJava、rxAndroid、Retrofit2 和 OkHTTP3 从 URL 端点下载文件。我的代码无法为 "Observable< retrofit2.Response< okhttp3.ResponseBody>>" 创建调用适配器。这些方法对我来说是新的，所以我相信我在这里遗漏了一个重要的概念。非常感谢任何方向或观点。
FATAL EXCEPTION: main
Process: com.example.khe11e.rxdownloadfile, PID: 14130
java.lang.IllegalArgumentException: Unable to create call adapter for io.reactivex.Observable>
for method RetrofitInterface.downloadFileByUrlRx
at retrofit2.ServiceMethod$Builder.methodError(ServiceMethod.java:720)
at retrofit2.ServiceMethod$Builder.createCallAdapter(ServiceMethod.java:234)
at retrofit2.ServiceMethod$Builder.build(ServiceMethod.java:160)
at retrofit2.Retrofit.loadServiceMethod(Retrofit.java:166)
at retrofit2.Retrofit.invoke(Retrofit.java:145)
at java.lang.reflect.Proxy.invoke(Proxy.java:393)
at $Proxy0.downloadFileByUrlRx(Unknown Source)
at com.example.khe11e.rxdownloadfile.MainActivity.downloadImage(MainActivity.java:46)
at com.example.khe11e.rxdownloadfile.MainActivity.onClick(MainActivity.java:39)
at android.view.View.performClick(View.java:5207)
at android.view.View$PerformClick.run(View.java:21168)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5491)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: java.lang.IllegalArgumentException: Could not locate call adapter for io.reactivex.Observable>.
Tried:
* retrofit2.adapter.rxjava.RxJavaCallAdapterFactory
* retrofit2.ExecutorCallAdapterFactory
at retrofit2.Retrofit.nextCallAdapter(Retrofit.java:237)
at retrofit2.Retrofit.callAdapter(Retrofit.java:201)
at retrofit2.ServiceMethod$Builder.createCallAdapter(ServiceMethod.java:232)
... 16 more
build.gradle:
compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'io.reactivex.rxjava2:rxjava:2.0.4'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
RetrofitInterface.java:
package com.example.khe11e.rxdownloadfile;
import io.reactivex.Observable;
import okhttp3.ResponseBody;
import retrofit2.Call;
import retrofit2.Response;
import retrofit2.http.GET;
import retrofit2.http.Streaming;
import retrofit2.http.Url;
public interface RetrofitInterface {
// Retrofit 2 GET request for rxjava
@Streaming
@GET
Observable<Response<ResponseBody>> downloadFileByUrlRx(@Url String fileUrl);
}
MainActivity.java:
package com.example.khe11e.rxdownloadfile;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import java.io.File;
import io.reactivex.Observable;
import io.reactivex.ObservableEmitter;
import io.reactivex.ObservableOnSubscribe;
import io.reactivex.Observer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Function;
import io.reactivex.schedulers.Schedulers;
import okhttp3.OkHttpClient;
import okhttp3.ResponseBody;
import okio.BufferedSink;
import okio.Okio;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
public class MainActivity extends AppCompatActivity {
Button downloadImgBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
downloadImgBtn = (Button) findViewById(R.id.downloadImgBtn);
downloadImgBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
downloadImage();
}
});
}
public void downloadImage(){
RetrofitInterface downloadService = createService(RetrofitInterface.class, "https://www.nasa.gov/");
downloadService.downloadFileByUrlRx("sites/default/files/iss_1.jpg")
.flatMap(processResponse())
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(handleResult());
}
public <T> T createService(Class<T> serviceClass, String baseUrl){
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(baseUrl)
.client(new OkHttpClient.Builder().build())
.addCallAdapterFactory(RxJavaCallAdapterFactory.create()).build();
return retrofit.create(serviceClass);
}
public Function<Response<ResponseBody>, Observable<File>> processResponse(){
return new Function<Response<ResponseBody>, Observable<File>>() {
@Override
public Observable<File> apply(Response<ResponseBody> responseBodyResponse) throws Exception {
return saveToDiskRx(responseBodyResponse);
}
};
}
private Observable<File> saveToDiskRx(final Response<ResponseBody> response){
return Observable.create(new ObservableOnSubscribe<File>() {
@Override
public void subscribe(ObservableEmitter<File> subscriber) throws Exception {
String header = response.headers().get("Content-Disposition");
String filename = header.replace("attachment; filename=", "");
new File("/data/data/" + getPackageName() + "/images").mkdir();
File destinationFile = new File("/data/data/" + getPackageName() + "/images/" + filename);
BufferedSink bufferedSink = Okio.buffer(Okio.sink(destinationFile));
bufferedSink.writeAll(response.body().source());
bufferedSink.close();
subscriber.onNext(destinationFile);
subscriber.onComplete();
}
});
}
private Observer<File> handleResult(){
return new Observer<File>() {
@Override
public void onSubscribe(Disposable d) {
Log.d("OnSubscribe", "OnSubscribe");
}
@Override
public void onNext(File file) {
Log.d("OnNext", "File downloaded to " + file.getAbsolutePath());
}
@Override
public void onError(Throwable e) {
e.printStackTrace();
Log.d("Error", "Error " + e.getMessage());
}
@Override
public void onComplete() {
Log.d("OnComplete", "onCompleted");
}
};
}
}
我已经尝试按照提到的方式添加 Call 所以它看起来像：
Call<Observable<Response<ResponseBody>>> downloadFileByUrlRx(@Url String fileUrl);
然而，这会导致 flatMap 函数出现问题，因为它找不到符号方法 flatMap(Function< Response< ResponseBody>,Observable< File>>)。
因为你使用了响应头，所以把ResponseBody到处替换成Object。
您正在使用 RxJava1 适配器进行改造，将其替换为 RxJava2 变体：
//compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
compile 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
更新
从 Retrofit 版本 2.2.0 开始，RxJava2 有一个 first-party 调用适配器：
compile 'com.squareup.retrofit2:retrofit:2.2.0'
compile 'com.squareup.retrofit2:adapter-rxjava2:2.2.0'
更新：May/2020
Rx 的新适配器Java 3
implementation 'io.reactivex.rxjava3:rxandroid:3.0.0'
implementation 'io.reactivex.rxjava3:rxjava:3.0.0'
implementation 'com.squareup.retrofit2:adapter-rxjava3:2.9.0'
RxJava3CallAdapterFactory.create() 而不是 RxJava2CallAdapterFactory.create()
更新：June/2019
Rxjava版本更新到2.2.10
compile 'io.reactivex.rxjava2:rxandroid:2.1.1'
compile 'io.reactivex.rxjava2:rxjava:2.2.10'
compile 'com.squareup.retrofit2:retrofit:2.6.0'
compile 'com.squareup.retrofit2:adapter-rxjava2:2.6.0'
此外，Retrofit 至少需要 Java 7 或 Android 2.3
------------------------------------------
对于新来者 (July/2017) :
你肯定搞砸了你的库版本。
我一直在使用最新版本的RXAndroid 2.0.1
compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'io.reactivex.rxjava2:rxjava:2.1.0'
compile 'com.squareup.retrofit2:retrofit:2.3.0'
compile 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
1) 确保您有相同的 Retrofit 和 Retrofit-RxJava 适配器。
2) 使用编译
compile 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
不是
compile 'com.squareup.retrofit2:adapter-rxjava:2.3.0'
并在改造时使用 RxJava2CallAdapterFactory.create() 而不是 RxJavaCallAdapterFactory.create()。
我正在尝试使用 rxJava、rxAndroid、Retrofit2 和 OkHTTP3 从 URL 端点下载文件。我的代码无法为 "Observable< retrofit2.Response< okhttp3.ResponseBody>>" 创建调用适配器。这些方法对我来说是新的，所以我相信我在这里遗漏了一个重要的概念。非常感谢任何方向或观点。
FATAL EXCEPTION: main Process: com.example.khe11e.rxdownloadfile, PID: 14130 java.lang.IllegalArgumentException: Unable to create call adapter for io.reactivex.Observable> for method RetrofitInterface.downloadFileByUrlRx at retrofit2.ServiceMethod$Builder.methodError(ServiceMethod.java:720) at retrofit2.ServiceMethod$Builder.createCallAdapter(ServiceMethod.java:234) at retrofit2.ServiceMethod$Builder.build(ServiceMethod.java:160) at retrofit2.Retrofit.loadServiceMethod(Retrofit.java:166) at retrofit2.Retrofit.invoke(Retrofit.java:145) at java.lang.reflect.Proxy.invoke(Proxy.java:393) at $Proxy0.downloadFileByUrlRx(Unknown Source) at com.example.khe11e.rxdownloadfile.MainActivity.downloadImage(MainActivity.java:46) at com.example.khe11e.rxdownloadfile.MainActivity.onClick(MainActivity.java:39) at android.view.View.performClick(View.java:5207) at android.view.View$PerformClick.run(View.java:21168) at android.os.Handler.handleCallback(Handler.java:746) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5491) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) Caused by: java.lang.IllegalArgumentException: Could not locate call adapter for io.reactivex.Observable>. Tried: * retrofit2.adapter.rxjava.RxJavaCallAdapterFactory * retrofit2.ExecutorCallAdapterFactory at retrofit2.Retrofit.nextCallAdapter(Retrofit.java:237) at retrofit2.Retrofit.callAdapter(Retrofit.java:201) at retrofit2.ServiceMethod$Builder.createCallAdapter(ServiceMethod.java:232) ... 16 more
build.gradle:
compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'io.reactivex.rxjava2:rxjava:2.0.4'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
RetrofitInterface.java:
package com.example.khe11e.rxdownloadfile;
import io.reactivex.Observable;
import okhttp3.ResponseBody;
import retrofit2.Call;
import retrofit2.Response;
import retrofit2.http.GET;
import retrofit2.http.Streaming;
import retrofit2.http.Url;
public interface RetrofitInterface {
// Retrofit 2 GET request for rxjava
@Streaming
@GET
Observable<Response<ResponseBody>> downloadFileByUrlRx(@Url String fileUrl);
}
MainActivity.java:
package com.example.khe11e.rxdownloadfile;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import java.io.File;
import io.reactivex.Observable;
import io.reactivex.ObservableEmitter;
import io.reactivex.ObservableOnSubscribe;
import io.reactivex.Observer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Function;
import io.reactivex.schedulers.Schedulers;
import okhttp3.OkHttpClient;
import okhttp3.ResponseBody;
import okio.BufferedSink;
import okio.Okio;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
public class MainActivity extends AppCompatActivity {
Button downloadImgBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
downloadImgBtn = (Button) findViewById(R.id.downloadImgBtn);
downloadImgBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
downloadImage();
}
});
}
public void downloadImage(){
RetrofitInterface downloadService = createService(RetrofitInterface.class, "https://www.nasa.gov/");
downloadService.downloadFileByUrlRx("sites/default/files/iss_1.jpg")
.flatMap(processResponse())
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(handleResult());
}
public <T> T createService(Class<T> serviceClass, String baseUrl){
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(baseUrl)
.client(new OkHttpClient.Builder().build())
.addCallAdapterFactory(RxJavaCallAdapterFactory.create()).build();
return retrofit.create(serviceClass);
}
public Function<Response<ResponseBody>, Observable<File>> processResponse(){
return new Function<Response<ResponseBody>, Observable<File>>() {
@Override
public Observable<File> apply(Response<ResponseBody> responseBodyResponse) throws Exception {
return saveToDiskRx(responseBodyResponse);
}
};
}
private Observable<File> saveToDiskRx(final Response<ResponseBody> response){
return Observable.create(new ObservableOnSubscribe<File>() {
@Override
public void subscribe(ObservableEmitter<File> subscriber) throws Exception {
String header = response.headers().get("Content-Disposition");
String filename = header.replace("attachment; filename=", "");
new File("/data/data/" + getPackageName() + "/images").mkdir();
File destinationFile = new File("/data/data/" + getPackageName() + "/images/" + filename);
BufferedSink bufferedSink = Okio.buffer(Okio.sink(destinationFile));
bufferedSink.writeAll(response.body().source());
bufferedSink.close();
subscriber.onNext(destinationFile);
subscriber.onComplete();
}
});
}
private Observer<File> handleResult(){
return new Observer<File>() {
@Override
public void onSubscribe(Disposable d) {
Log.d("OnSubscribe", "OnSubscribe");
}
@Override
public void onNext(File file) {
Log.d("OnNext", "File downloaded to " + file.getAbsolutePath());
}
@Override
public void onError(Throwable e) {
e.printStackTrace();
Log.d("Error", "Error " + e.getMessage());
}
@Override
public void onComplete() {
Log.d("OnComplete", "onCompleted");
}
};
}
}
我已经尝试按照提到的方式添加 Call
Call<Observable<Response<ResponseBody>>> downloadFileByUrlRx(@Url String fileUrl);
然而，这会导致 flatMap 函数出现问题，因为它找不到符号方法 flatMap(Function< Response< ResponseBody>,Observable< File>>)。
因为你使用了响应头，所以把ResponseBody到处替换成Object。
您正在使用 RxJava1 适配器进行改造，将其替换为 RxJava2 变体：
//compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
compile 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
更新
从 Retrofit 版本 2.2.0 开始，RxJava2 有一个 first-party 调用适配器：
compile 'com.squareup.retrofit2:retrofit:2.2.0'
compile 'com.squareup.retrofit2:adapter-rxjava2:2.2.0'
更新：May/2020
Rx 的新适配器Java 3
implementation 'io.reactivex.rxjava3:rxandroid:3.0.0'
implementation 'io.reactivex.rxjava3:rxjava:3.0.0'
implementation 'com.squareup.retrofit2:adapter-rxjava3:2.9.0'
RxJava3CallAdapterFactory.create() 而不是 RxJava2CallAdapterFactory.create()
更新：June/2019
Rxjava版本更新到2.2.10
compile 'io.reactivex.rxjava2:rxandroid:2.1.1'
compile 'io.reactivex.rxjava2:rxjava:2.2.10'
compile 'com.squareup.retrofit2:retrofit:2.6.0'
compile 'com.squareup.retrofit2:adapter-rxjava2:2.6.0'
此外，Retrofit 至少需要 Java 7 或 Android 2.3
------------------------------------------
对于新来者 (July/2017) :
你肯定搞砸了你的库版本。
我一直在使用最新版本的RXAndroid 2.0.1
compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'io.reactivex.rxjava2:rxjava:2.1.0'
compile 'com.squareup.retrofit2:retrofit:2.3.0'
compile 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
1) 确保您有相同的 Retrofit 和 Retrofit-RxJava 适配器。
2) 使用编译
compile 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
不是
compile 'com.squareup.retrofit2:adapter-rxjava:2.3.0'
并在改造时使用 RxJava2CallAdapterFactory.create() 而不是 RxJavaCallAdapterFactory.create()。