stream improvment #295 - pageSplitter introduction

Author: mariuszs

src/main/java/org/gitlab4j/api/PagerSpliterator.java

@@ -0,0 +1,60 @@
+package org.gitlab4j.api;
+
+import java.util.List;
+import java.util.Spliterator;
+import java.util.function.Consumer;
+
+public class PagerSpliterator<T> implements Spliterator<T> {
+
+	private Pager<T> pager;
+
+	private List<T> list;
+	private int current;
+
+	public PagerSpliterator(Pager<T> pager) {
+		this.pager = pager;
+	}
+
+	@Override
+	public boolean tryAdvance(Consumer<? super T> action) {
+
+		if (list == null) {
+			if (pager.hasNext()) {
+				resetList();
+			} else {
+				return false;
+			}
+		}
+
+		if (current < list.size()) {
+			action.accept(list.get(current));
+			current++;
+			return true;
+		} else if (pager.hasNext()) {
+			resetList();
+			action.accept(list.get(current));
+			return true;
+		}
+		return false;
+	}
+
+	private void resetList() {
+		list = pager.next();
+		current = 0;
+	}
+
+	@Override
+	public Spliterator<T> trySplit() {
+		return null;
+	}
+
+	@Override
+	public long estimateSize() {
+		return pager.getTotalItems();
+	}
+
+	@Override
+	public int characteristics() {
+		return 0;
+	}
+}

src/main/java/org/gitlab4j/api/ProjectApi.java

@@ -31,6 +31,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
@@ -109,7 +110,7 @@ public Pager<Project> getProjects(int itemsPerPage) throws GitLabApiException {
      * @throws GitLabApiException if any exception occurs
      */
     public Stream<Project> getProjectsStream() throws GitLabApiException {
-       return (getProjects(getDefaultPerPage()).stream());
+	    return StreamSupport.stream(new PagerSpliterator(getProjects(getDefaultPerPage())), false);
     }
 
     /**
@@ -818,15 +819,15 @@ public Project createProject(Project project, String importUrl) throws GitLabApi
         if (isApiVersion(ApiVersion.V3)) {
             boolean isPublic = (project.getPublic() != null ? project.getPublic() : project.getVisibility() == Visibility.PUBLIC);
             formData.withParam("public", isPublic);
-            
+
             if (project.getTagList() != null && !project.getTagList().isEmpty()) {
                 throw new IllegalArgumentException("GitLab API v3 does not support tag lists when creating projects");
             }
         } else {
             Visibility visibility = (project.getVisibility() != null ? project.getVisibility() :
                 project.getPublic() == Boolean.TRUE ? Visibility.PUBLIC : null);
             formData.withParam("visibility", visibility);
-            
+
             if (project.getTagList() != null && !project.getTagList().isEmpty()) {
                 formData.withParam("tag_list", String.join(",", project.getTagList()));
             }
@@ -1057,15 +1058,15 @@ public Project updateProject(Project project) throws GitLabApiException {
             formData.withParam("visibility_level", project.getVisibilityLevel());
             boolean isPublic = (project.getPublic() != null ? project.getPublic() : project.getVisibility() == Visibility.PUBLIC);
             formData.withParam("public", isPublic);
-            
+
             if (project.getTagList() != null && !project.getTagList().isEmpty()) {
                 throw new IllegalArgumentException("GitLab API v3 does not support tag lists when updating projects");
             }
         } else {
             Visibility visibility = (project.getVisibility() != null ? project.getVisibility() :
                 project.getPublic() == Boolean.TRUE ? Visibility.PUBLIC : null);
             formData.withParam("visibility", visibility);
-            
+
             if (project.getTagList() != null && !project.getTagList().isEmpty()) {
                 formData.withParam("tag_list", String.join(",", project.getTagList()));
             }
@@ -1090,7 +1091,7 @@ public void deleteProject(Object projectIdOrPath) throws GitLabApiException {
 
     /**
      * Forks a project into the user namespace of the authenticated user or the one provided.
-     * The forking operation for a project is asynchronous and is completed in a background job. 
+     * The forking operation for a project is asynchronous and is completed in a background job.
      * The request will return immediately.
      *
      * <pre><code>POST /projects/:id/fork</code></pre>
@@ -1109,7 +1110,7 @@ public Project forkProject(Object projectIdOrPath, String namespace) throws GitL
 
     /**
      * Forks a project into the user namespace of the authenticated user or the one provided.
-     * The forking operation for a project is asynchronous and is completed in a background job. 
+     * The forking operation for a project is asynchronous and is completed in a background job.
      * The request will return immediately.
      *
      * <pre><code>POST /projects/:id/fork</code></pre>
@@ -1130,7 +1131,7 @@ public Project forkProject(Object projectIdOrPath, Integer namespaceId) throws G
      * Create a forked from/to relation between existing projects.
      *
      * <pre><code>POST /projects/:id/fork/:forkFromId</code></pre>
-     * 
+     *
      *
      * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param forkedFromId the ID of the project that was forked from
@@ -1455,7 +1456,7 @@ public List<ProjectUser> getProjectUsers(Object projectIdOrPath, String search)
     }
 
     /**
-     * Get a Pager of project users matching the specified search string. This Pager includes 
+     * Get a Pager of project users matching the specified search string. This Pager includes
      * all project members and all users assigned to project parent groups.
      *
      * <pre><code>GET /projects/:id/users</code></pre>
@@ -1644,7 +1645,7 @@ public Optional<ProjectHook> getOptionalHook(Object projectIdOrPath, Integer hoo
      * @return the added ProjectHook instance
      * @throws GitLabApiException if any exception occurs
      */
-    public ProjectHook addHook(String projectName, String url, ProjectHook enabledHooks, boolean enableSslVerification, String secretToken) 
+    public ProjectHook addHook(String projectName, String url, ProjectHook enabledHooks, boolean enableSslVerification, String secretToken)
             throws GitLabApiException {
 
         if (projectName == null) {
@@ -2266,9 +2267,9 @@ public void deletePushRules(Object projectIdOrPath) throws GitLabApiException {
 
     /**
      * Get a list of projects that were forked from the specified project.
-     * 
+     *
      * <pre><code>GET /projects/:id/forks</code></pre>
-     * 
+     *
      * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @return a List of forked projects
      * @throws GitLabApiException if any exception occurs
@@ -2382,7 +2383,7 @@ public Project transferProject(Object projectIdOrPath, String namespace) throws
     }
 
     /**
-     * Uploads and sets the project avatar for the specified project. 
+     * Uploads and sets the project avatar for the specified project.
      *
      * <pre><code>PUT /projects/:id/uploads</code></pre>
      *