I am stuck in one implementation. I am developing an Android application, into which I integrated 3rd party SDK (library) and calling its APIs. Function calling of SDK is actually Async calls (WebAPI calls called by the library) which gives a response (success or failure).
Now, I am trying to explain the situation by code.
for (................) {
AsyncAPICall (SuccessListener {
onSuccess() {
for (................) {
AsyncAPICall (SuccessListener {
onSuccess() {
for (................) {
AsyncAPICall (SuccessListener, ErrorListener);
}
}
}, ErrorListener);
}
}
}, ErrorListener);
}
I want notification or callback or be informed by something that all Async calls are completed. Async calls are run in a different thread and due to for loop, many calls will be done simultaneously.
Is there any mechanism which informs me once all Async call received responses or I need to do manually something?
Any help?
@Khushbu Shah, I updated my answer, it changes a bit :) (it's pretty long).
To make sure it's working, I created a stand alone working example and use this API to test: https://jsonplaceholder.typicode.com/posts/1
private final Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://jsonplaceholder.typicode.com/posts/")
.addConverterFactory(GsonConverterFactory.create())
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
.build();
private final RestPostsService restPostsService = retrofit.create(RestPostsService.class);
private Observable<Posts> getPostById(int id) {
return restPostsService.getPostsById(id);
}
Solution1: Use when call multiple tasks in sequences, the result of previous tasks is always the input of the next task
getPostById(1)
.concatMap(posts1 -> {
//get post 1 success
return getPostById(posts1.getId() + 1);
})
.concatMap(posts2 -> {
//get post 2 success
return getPostById(posts2.getId() + 1);
})
.concatMap(posts3 -> {
//get post 3success
return getPostById(posts3.getId() + 1);
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(finalPosts -> {
//get post 4 success
Toast.makeText(this, "Final result: " + finalPosts.getId() + " - " + finalPosts.getTitle(),
Toast.LENGTH_LONG).show();
});
Solution2: Use when call multiple tasks in sequences, all results of previous tasks is the input of the final task (for example: after uploading avatar image and cover image, call api to create new user with these image URLs):
Observable
.zip(getPostById(1), getPostById(2), getPostById(3), (posts1, posts2, posts3) -> {
//this method defines how to zip all separate results into one
return posts1.getId() + posts2.getId() + posts3.getId();
})
.flatMap(finalPostId -> {
//after get all first three posts, get the final posts,
// the final posts-id is sum of these posts-id
return getPostById(finalPostId);
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(finalPosts -> {
Toast.makeText(this, "Final posts: " + finalPosts.getId() + " - " + finalPosts.getTitle(),
Toast.LENGTH_SHORT).show();
});
AndroidManifest
<uses-permission android:name="android.permission.INTERNET"/>
root build.gradle
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.3.3'
classpath 'me.tatarka:gradle-retrolambda:3.2.0'
classpath 'me.tatarka.retrolambda.projectlombok:lombok.ast:0.2.3.a2'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
// Exclude the version that the android plugin depends on.
configurations.classpath.exclude group: 'com.android.tools.external.lombok'
}
allprojects {
repositories {
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
app/build.gradle
apply plugin: 'me.tatarka.retrolambda'
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
buildToolsVersion "26.0.1"
defaultConfig {
applicationId "app.com.rxretrofit"
minSdkVersion 15
targetSdkVersion 26
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:26.+'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testCompile 'junit:junit:4.12'
provided 'org.projectlombok:lombok:1.16.6'
compile 'com.squareup.retrofit2:retrofit:2.3.0'
compile 'com.squareup.retrofit2:converter-gson:2.3.0'
compile 'com.squareup.retrofit2:adapter-rxjava:2.3.0'
compile 'io.reactivex:rxandroid:1.2.1'
}
model
package app.com.rxretrofit;
import com.google.gson.annotations.SerializedName;
/**
* -> Created by Think-Twice-Code-Once on 11/26/2017.
*/
public class Posts {
@SerializedName("userId")
private int userId;
@SerializedName("id")
private int id;
@SerializedName("title")
private String title;
@SerializedName("body")
private String body;
public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
}
RestPostService.java
package app.com.rxretrofit;
import retrofit2.http.GET;
import retrofit2.http.Path;
import rx.Observable;
/**
* -> Created by Think-Twice-Code-Once on 11/26/2017.
*/
public interface RestPostsService {
@GET("{id}")
Observable<Posts> getPostsById(@Path("id") int id);
}
By the way, use Rx + Retrofit + Dagger + MVP pattern is a great combine.
