Retrofit rx (#2519)

* Retrofit with RxJava

* Correct spelling mistake

* Use spaces for indentation instead of tabs in pom.xml

* Use spaces for indentation instead of tabs in pom.xml

* Add Retrofit integration with RxJava to libraries module

* Remove standalone project for Retrofit integration with RxJava

* remove retrofit-rxjava module

* Fixed error in pom.xml caused by an issue while merging

* Retrofit integration with RxJava

* Fix test cases

* Fix merge issues

* BAEL-1016 Merging master

libraries/src/main/java/com/baeldung/retrofit/basic/GitHubBasicApi.java

@@ -0,0 +1,33 @@
+package com.baeldung.retrofit.basic;
+
+import java.util.List;
+
+import com.baeldung.retrofit.models.Contributor;
+import com.baeldung.retrofit.models.Repository;
+
+import retrofit2.Call;
+import retrofit2.http.GET;
+import retrofit2.http.Path;
+
+public interface GitHubBasicApi {
+
+    /**
+     * List GitHub repositories of user
+     * @param user GitHub Account
+     * @return GitHub repositories
+     */
+    @GET("users/{user}/repos")
+    Call<List<Repository>> listRepos(@Path("user") String user);
+    
+    /**
+     * List Contributors of a GitHub Repository
+     * @param user GitHub Account
+     * @param repo GitHub Repository
+     * @return GitHub Repository Contributors
+     */
+    @GET("repos/{user}/{repo}/contributors")
+    Call<List<Contributor>> listRepoContributors(
+      @Path("user") String user,
+      @Path("repo") String repo);
+    
+}

libraries/src/main/java/com/baeldung/retrofit/basic/GitHubBasicApp.java

@@ -0,0 +1,14 @@
+package com.baeldung.retrofit.basic;
+
+import java.io.IOException;
+import java.util.List;
+
+public class GitHubBasicApp {
+    
+    public static void main(String[] args) throws IOException {
+        String userName = "eugenp";
+        List<String> topContributors = new GitHubBasicService().getTopContributors(userName);
+        topContributors.stream().forEach(System.out::println);
+    }
+
+}

libraries/src/main/java/com/baeldung/retrofit/basic/GitHubBasicService.java

@@ -0,0 +1,54 @@
+package com.baeldung.retrofit.basic;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import com.baeldung.retrofit.models.Contributor;
+import com.baeldung.retrofit.models.Repository;
+
+import retrofit2.Retrofit;
+import retrofit2.converter.gson.GsonConverterFactory;
+
+public class GitHubBasicService {
+    
+    private GitHubBasicApi gitHubApi;
+    
+    public GitHubBasicService() {
+        Retrofit retrofit = new Retrofit.Builder()
+            .baseUrl("https://api.github.com/")
+            .addConverterFactory(GsonConverterFactory.create())
+            .build();
+          
+          gitHubApi = retrofit.create(GitHubBasicApi.class);
+    }
+    
+    public List<String> getTopContributors(String userName) throws IOException {
+        List<Repository> repos = gitHubApi
+          .listRepos(userName)
+          .execute()
+          .body();
+        
+        List<Contributor> topContributors = new ArrayList<>();
+        for(Repository repo : repos) {
+            List<Contributor> contributers = gitHubApi
+              .listRepoContributors(userName, repo.getName())
+              .execute()
+              .body();
+            
+            List<Contributor> repoTopContributors = contributers.stream()
+              .filter(c -> c.getContributions() > 100)
+              .collect(Collectors.toList());
+            topContributors.addAll(repoTopContributors);
+        }
+        
+        Collections.sort(topContributors, (a, b) -> b.getContributions() - a.getContributions());
+        return topContributors.stream()
+          .map(c -> c.getName())
+          .distinct()
+          .collect(Collectors.toList());
+    }
+
+}

libraries/src/main/java/com/baeldung/retrofit/models/Contributor.java

@@ -0,0 +1,35 @@
+package com.baeldung.retrofit.models;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * GitHub Contributer
+ * @author hany
+ *
+ */
+public class Contributor {
+    
+    @SerializedName("login")
+    private String name;
+    
+    private Integer contributions;
+    
+    public String getName() {
+        return name;
+    }
+    public void setName(String name) {
+        this.name = name;
+    }
+    public Integer getContributions() {
+        return contributions;
+    }
+    public void setContributions(Integer contributions) {
+        this.contributions = contributions;
+    }
+    
+    @Override
+    public String toString() {
+        return "Contributer [name=" + name + ", contributions=" + contributions + "]";
+    }
+    
+}

libraries/src/main/java/com/baeldung/retrofit/models/Repository.java

@@ -0,0 +1,32 @@
+package com.baeldung.retrofit.models;
+
+/**
+ * GitHub Repository
+ * @author hany
+ *
+ */
+public class Repository {
+    
+    private String name;
+    
+    private String description;
+    
+    public String getName() {
+        return name;
+    }
+    public void setName(String name) {
+        this.name = name;
+    }
+    public String getDescription() {
+        return description;
+    }
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    @Override
+    public String toString() {
+        return "Repository [name=" + name + ", description=" + description + "]";
+    }
+
+}

libraries/src/main/java/com/baeldung/retrofit/rx/GitHubRxApi.java

@@ -0,0 +1,33 @@
+package com.baeldung.retrofit.rx;
+
+import java.util.List;
+
+import com.baeldung.retrofit.models.Contributor;
+import com.baeldung.retrofit.models.Repository;
+
+import retrofit2.http.GET;
+import retrofit2.http.Path;
+import rx.Observable;
+
+public interface GitHubRxApi {
+
+    /**
+     * List GitHub repositories of user
+     * @param user GitHub Account
+     * @return GitHub repositories
+     */
+    @GET("users/{user}/repos")
+    Observable<List<Repository>> listRepos(@Path("user") String user);
+    
+    /**
+     * List Contributors of a GitHub Repository
+     * @param user GitHub Account
+     * @param repo GitHub Repository
+     * @return GitHub Repository Contributors
+     */
+    @GET("repos/{user}/{repo}/contributors")
+    Observable<List<Contributor>> listRepoContributors(
+      @Path("user") String user,
+      @Path("repo") String repo);
+    
+}

libraries/src/main/java/com/baeldung/retrofit/rx/GitHubRxApp.java

@@ -0,0 +1,13 @@
+package com.baeldung.retrofit.rx;
+
+import java.io.IOException;
+
+public class GitHubRxApp {
+    
+    public static void main(String[] args) throws IOException {
+        String userName = "eugenp";
+        new GitHubRxService().getTopContributors(userName)
+          .subscribe(System.out::println);
+    }
+    
+}

libraries/src/main/java/com/baeldung/retrofit/rx/GitHubRxService.java

@@ -0,0 +1,33 @@
+package com.baeldung.retrofit.rx;
+
+import retrofit2.Retrofit;
+import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
+import retrofit2.converter.gson.GsonConverterFactory;
+import rx.Observable;
+
+public class GitHubRxService {
+    
+    private GitHubRxApi gitHubApi;
+    
+    public GitHubRxService() {
+        Retrofit retrofit = new Retrofit.Builder()
+            .baseUrl("https://api.github.com/")
+            .addConverterFactory(GsonConverterFactory.create())
+            .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
+            .build();
+        
+        gitHubApi = retrofit.create(GitHubRxApi.class);
+    }
+    
+    public Observable<String> getTopContributors(String userName) {
+        return gitHubApi.listRepos(userName)
+          .flatMap( repos -> Observable.from(repos))
+          .flatMap( repo -> gitHubApi.listRepoContributors(userName, repo.getName()) )
+          .flatMap( contributers -> Observable.from(contributers))
+          .filter( c -> c.getContributions() > 100)
+          .sorted( (a, b) -> b.getContributions() - a.getContributions() )
+          .map( c -> c.getName())
+          .distinct();
+    }
+
+}

libraries/src/test/java/com/baeldung/retrofit/basic/GitHubBasicApiTest.java

@@ -0,0 +1,65 @@
+package com.baeldung.retrofit.basic;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.retrofit.basic.GitHubBasicApi;
+import com.baeldung.retrofit.models.Contributor;
+import com.baeldung.retrofit.models.Repository;
+
+import retrofit2.Retrofit;
+import retrofit2.converter.gson.GsonConverterFactory;
+
+public class GitHubBasicApiTest {
+    
+    GitHubBasicApi gitHub;
+    
+    @Before
+    public void init() {
+        Retrofit retrofit = new Retrofit.Builder()
+          .baseUrl("https://api.github.com/")
+          .addConverterFactory(GsonConverterFactory.create())
+          .build();
+        
+        gitHub = retrofit.create(GitHubBasicApi.class);
+    }
+    
+    @Test
+    public void whenListRepos_thenExpectReposThatContainTutorials() {
+        try {
+            List<Repository> repos = gitHub
+              .listRepos("eugenp")
+              .execute()
+              .body();
+            
+            assertThat(repos)
+              .isNotEmpty()
+              .extracting(Repository::getName).contains("tutorials");
+        } catch (IOException e) {
+            fail("Can not communicate with GitHub API");
+        }
+    }
+    
+    @Test
+    public void whenListRepoContributers_thenExpectContributorsThatContainEugenp() {
+        try {
+            List<Contributor> contributors = gitHub
+              .listRepoContributors("eugenp", "tutorials")
+              .execute()
+              .body();
+            
+            assertThat(contributors)
+              .isNotEmpty()
+              .extracting(Contributor::getName).contains("eugenp");
+        } catch (IOException e) {
+            fail("Can not communicate with GitHub API");
+        }
+    }
+
+}

libraries/src/test/java/com/baeldung/retrofit/rx/GitHubRxApiTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.retrofit.rx;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.retrofit.models.Contributor;
+import com.baeldung.retrofit.models.Repository;
+import com.baeldung.retrofit.rx.GitHubRxApi;
+
+import retrofit2.Retrofit;
+import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
+import retrofit2.converter.gson.GsonConverterFactory;
+
+public class GitHubRxApiTest {
+    
+    GitHubRxApi gitHub;
+    
+    @Before
+    public void init() {
+        Retrofit retrofit = new Retrofit.Builder()
+          .baseUrl("https://api.github.com/")
+          .addConverterFactory(GsonConverterFactory.create())
+          .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
+          .build();
+        
+        gitHub = retrofit.create(GitHubRxApi.class);
+    }
+    
+    @Test
+    public void whenListRepos_thenExpectReposThatContainTutorials() {
+        gitHub
+          .listRepos("eugenp")
+          .subscribe( repos -> {
+              assertThat(repos)
+                .isNotEmpty()
+                .extracting(Repository::getName).contains("tutorials");
+          });
+    }
+    
+    @Test
+    public void whenListRepoContributers_thenExpectContributorsThatContainEugenp() {
+        gitHub
+          .listRepoContributors("eugenp", "tutorials")
+          .subscribe(contributors -> {
+              assertThat(contributors)
+                .isNotEmpty()
+                .extracting(Contributor::getName).contains("eugenp");
+          });
+    }
+
+}