Added API to get data from GitHub's Web API

This took me quite a long time, but I did it!

src/main/java/world/bentobox/bentobox/api/github/Contributor.java

@@ -0,0 +1,39 @@
+package world.bentobox.bentobox.api.github;
+
+import org.eclipse.jdt.annotation.NonNull;
+
+/**
+ * Represents a Contributor on a GitHub repository.
+ * @author Poslovitch
+ * @since 1.3.0
+ */
+public class Contributor {
+
+    private final @NonNull String name;
+    private final @NonNull String profile;
+    private int commits;
+
+    public Contributor(@NonNull String name, int commits) {
+        this.name = name;
+        this.profile = "https://github.com/" + name;
+        this.commits = commits;
+    }
+
+    @NonNull
+    public String getName() {
+        return name;
+    }
+
+    @NonNull
+    public String getProfile() {
+        return profile;
+    }
+
+    public int getCommits() {
+        return commits;
+    }
+
+    public void setCommits(int commits) {
+        this.commits = commits;
+    }
+}

src/main/java/world/bentobox/bentobox/api/github/GitHubConnector.java

@@ -0,0 +1,124 @@
+package world.bentobox.bentobox.api.github;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
+import world.bentobox.bentobox.util.Util;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.util.stream.Collectors;
+
+/**
+ * Handles connection to the GitHub API, retrieves data and handles the {@link Repository} data that emerges from it.
+ * @author Poslovitch
+ * @since 1.3.0
+ */
+public class GitHubConnector {
+
+    private @NonNull String repositoryName;
+    private Repository repository;
+
+    public GitHubConnector(@NonNull String repositoryName) {
+        this.repositoryName = repositoryName;
+    }
+
+    public void connect() {
+        JsonElement repositoryData;
+        JsonElement releasesData;
+        JsonElement contributorData;
+
+        // Get the data
+        try {
+            repositoryData = getData(null);
+            // TODO getting other data is pointless if we couldn't get the data from the repository
+            contributorData = getData("contributors");
+            releasesData = getData("releases");
+        } catch (IOException e) {
+            e.printStackTrace();
+            // TODO better logging and do not override data instead
+            return;
+        }
+
+        // Parse the data
+        /* It must be done in a specific order:
+
+            1. repository;
+            2. contributors;
+            3. releases.
+         */
+        parseRepositoryData(repositoryData);
+        parseContributorsData(contributorData);
+        parseReleasesData(releasesData);
+    }
+
+    @NonNull
+    private JsonElement getData(@Nullable String suffix) throws IOException {
+        HttpURLConnection connection = new GitHubURL(getRepositoryName(), suffix).openConnection();
+        String data = new BufferedReader(new InputStreamReader(connection.getInputStream())).lines().collect(Collectors.joining("\n"));
+        return new JsonParser().parse(data);
+    }
+
+    private void parseRepositoryData(@NonNull JsonElement jsonElement) {
+        JsonObject jsonObject = jsonElement.getAsJsonObject();
+
+        Repository.Builder builder = new Repository.Builder(repositoryName.split("/")[0], repositoryName.split("/")[1])
+                .stars(jsonObject.get("stargazers_count").getAsInt())
+                .forks(jsonObject.get("forks_count").getAsInt())
+                .openIssues(jsonObject.get("open_issues_count").getAsInt())
+                .latestCommit(Util.parseGitHubDate(jsonObject.get("pushed_at").getAsString()));
+
+        this.repository = builder.build();
+    }
+
+    private void parseContributorsData(@NonNull JsonElement jsonElement) {
+        for (JsonElement contributorElement : jsonElement.getAsJsonArray()) {
+            JsonObject contributor = contributorElement.getAsJsonObject();
+            this.repository.getContributors().add(new Contributor(contributor.get("login").getAsString(), contributor.get("contributions").getAsInt()));
+        }
+    }
+
+    private void parseReleasesData(@NonNull JsonElement jsonElement) {
+        for (JsonElement releaseElement : jsonElement.getAsJsonArray()) {
+            JsonObject release = releaseElement.getAsJsonObject();
+
+            String tag = release.get("tag_name").getAsString();
+            String url = repository.getUrl() + "/releases/tag/" + tag;
+
+            Release.Builder builder = new Release.Builder(release.get("name").getAsString(), tag, url)
+                    .preRelease(release.get("prerelease").getAsBoolean())
+                    .publishedAt(Util.parseGitHubDate( release.get("published_at").getAsString()));
+
+            // Run through the releases assets and try to find the correct one
+            for (JsonElement assetElement : release.get("assets").getAsJsonArray()) {
+                JsonObject asset = assetElement.getAsJsonObject();
+
+                String assetName = asset.get("name").getAsString();
+                if (assetName.endsWith(".jar") && !assetName.contains("javadoc") && !assetName.contains("sources")) {
+                    // We found our asset!
+
+                    builder.downloadUrl(asset.get("browser_download_url").getAsString())
+                            .downloadSize(asset.get("size").getAsLong())
+                            .downloadCount(asset.get("download_count").getAsInt());
+
+                    break;
+                }
+            }
+
+            this.repository.getReleases().add(builder.build());
+        }
+    }
+
+    @NonNull
+    public String getRepositoryName() {
+        return repositoryName;
+    }
+
+    public Repository getRepository() {
+        return repository;
+    }
+}

src/main/java/world/bentobox/bentobox/api/github/GitHubURL.java

@@ -0,0 +1,37 @@
+package world.bentobox.bentobox.api.github;
+
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+/**
+ * Somehow wraps {@link URL} and {@link java.net.URLConnection} to avoid boilerplate code when accessing to the GitHub API.
+ * @author Poslovitch
+ * @since 1.3.0
+ */
+public class GitHubURL {
+
+    private @NonNull final URL url;
+
+    public GitHubURL(@NonNull String repository, @Nullable String suffix) throws MalformedURLException {
+        suffix = (suffix != null && !suffix.isEmpty()) ? "/" + suffix : "";
+        this.url = new URL("https://api.github.com/repos/" + repository + suffix);
+    }
+
+    @NonNull
+    public URL toURL() {
+        return url;
+    }
+
+    public HttpURLConnection openConnection() throws IOException {
+        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+        connection.setConnectTimeout(2500);
+        connection.addRequestProperty("User-Agent", "BentoBox GitHubLink (@BentoBoxWorld)");
+        connection.setDoOutput(true);
+        return connection;
+    }
+}

src/main/java/world/bentobox/bentobox/api/github/Release.java

@@ -0,0 +1,130 @@
+package world.bentobox.bentobox.api.github;
+
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
+
+import java.util.Date;
+
+/**
+ * Represents a release on a Github repository.
+ * See https://api.github.com/repos/BentoBoxWorld/BentoBox/releases.
+ * @author Poslovitch
+ * @since 1.3.0
+ */
+public class Release {
+
+    private final @NonNull String name;
+    private final @NonNull String tag;
+    private final @NonNull String url;
+
+    private final boolean preRelease;
+    private final @Nullable Date publishedAt;
+
+    /* Release asset related fields */
+    private final @Nullable String downloadUrl;
+    private final long downloadSize;
+    private int downloadCount;
+
+    private Release(@NonNull Builder builder) {
+        this.name = builder.name;
+        this.tag = builder.tag;
+        this.url = builder.url;
+        this.preRelease = builder.preRelease;
+        this.publishedAt = builder.publishedAt;
+        this.downloadUrl = builder.downloadUrl;
+        this.downloadSize = builder.downloadSize;
+        this.downloadCount = builder.downloadCount;
+    }
+
+    @NonNull
+    public String getName() {
+        return name;
+    }
+
+    @NonNull
+    public String getTag() {
+        return tag;
+    }
+
+    @NonNull
+    public String getUrl() {
+        return url;
+    }
+
+    public boolean isPreRelease() {
+        return preRelease;
+    }
+
+    @Nullable
+    public Date getPublishedAt() {
+        return publishedAt;
+    }
+
+    @Nullable
+    public String getDownloadUrl() {
+        return downloadUrl;
+    }
+
+    public long getDownloadSize() {
+        return downloadSize;
+    }
+
+    public int getDownloadCount() {
+        return downloadCount;
+    }
+
+    public void setDownloadCount(int downloadCount) {
+        this.downloadCount = downloadCount;
+    }
+
+    public static class Builder {
+        private final @NonNull String name;
+        private final @NonNull String tag;
+        private final @NonNull String url;
+
+        private boolean preRelease;
+        private @Nullable Date publishedAt;
+        private @Nullable String downloadUrl;
+        private long downloadSize;
+        private int downloadCount;
+
+        public Builder(@NonNull String name, @NonNull String tag, @NonNull String url) {
+            this.name = name;
+            this.tag = tag;
+            this.url = url;
+            this.preRelease = false;
+            this.downloadSize = 0L;
+            this.downloadCount = 0;
+        }
+
+        public Builder preRelease(boolean preRelease) {
+            this.preRelease = preRelease;
+            return this;
+        }
+
+        public Builder publishedAt(@Nullable Date publishedAt) {
+            this.publishedAt = publishedAt;
+            return this;
+        }
+
+        public Builder downloadUrl(@Nullable String downloadUrl) {
+            this.downloadUrl = downloadUrl;
+            return this;
+        }
+
+        public Builder downloadSize(long downloadSize) {
+            this.downloadSize = downloadSize;
+            return this;
+        }
+
+        public Builder downloadCount(int downloadCount) {
+            this.downloadCount = downloadCount;
+            return this;
+        }
+
+        public Release build() {
+            return new Release(this);
+        }
+    }
+
+}

src/main/java/world/bentobox/bentobox/api/github/Repository.java

@@ -0,0 +1,152 @@
+package world.bentobox.bentobox.api.github;
+
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
+
+import java.util.Arrays;
+import java.util.Date;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * Represents a GitHub repository.
+ * @author Poslovitch
+ * @since 1.3.0
+ */
+public class Repository {
+
+    private final @NonNull String owner;
+    private final @NonNull String name;
+
+    private final @NonNull List<Contributor> contributors;
+    private final @NonNull List<Release> releases;
+
+    private int stars;
+    private int forks;
+    private int openIssues;
+
+    private @Nullable Date latestCommit;
+
+    private Repository(@NonNull Builder builder) {
+        this.owner = builder.owner;
+        this.name = builder.name;
+        this.contributors = builder.contributors;
+        this.releases = builder.releases;
+
+        this.stars = builder.stars;
+        this.forks = builder.forks;
+        this.openIssues = builder.openIssues;
+        this.latestCommit = builder.latestCommit;
+    }
+
+    @NonNull
+    public String getOwner() {
+        return owner;
+    }
+
+    @NonNull
+    public String getName() {
+        return name;
+    }
+
+    @NonNull
+    public List<Contributor> getContributors() {
+        return contributors;
+    }
+
+    @NonNull
+    public List<Release> getReleases() {
+        return releases;
+    }
+
+    public int getStars() {
+        return stars;
+    }
+
+    public void setStars(int stars) {
+        this.stars = stars;
+    }
+
+    public int getForks() {
+        return forks;
+    }
+
+    public void setForks(int forks) {
+        this.forks = forks;
+    }
+
+    public int getOpenIssues() {
+        return openIssues;
+    }
+
+    public void setOpenIssues(int openIssues) {
+        this.openIssues = openIssues;
+    }
+
+    @NonNull
+    public String getUrl() {
+        return "https://github.com/" + getOwner() + "/" + getName();
+    }
+
+    @Nullable
+    public Date getLatestCommit() {
+        return latestCommit;
+    }
+
+    public void setLatestCommit(@Nullable Date latestCommit) {
+        this.latestCommit = latestCommit;
+    }
+
+    public static class Builder {
+        private final @NonNull String owner;
+        private final @NonNull String name;
+        private final @NonNull List<Contributor> contributors;
+        private final @NonNull List<Release> releases;
+
+        private int stars;
+        private int forks;
+        private int openIssues;
+        private @Nullable Date latestCommit;
+
+        public Builder(@NonNull String owner, @NonNull String name) {
+            this.owner = owner;
+            this.name = name;
+            this.contributors = new LinkedList<>();
+            this.releases = new LinkedList<>();
+        }
+
+        public Builder contributors(@NonNull Contributor... contributors) {
+            this.contributors.addAll(Arrays.asList(contributors));
+            return this;
+        }
+
+        public Builder releases(@NonNull Release... releases) {
+            this.releases.addAll(Arrays.asList(releases));
+            return this;
+        }
+
+        public Builder stars(int stars) {
+            this.stars = stars;
+            return this;
+        }
+
+        public Builder forks(int forks) {
+            this.forks = forks;
+            return this;
+        }
+
+        public Builder openIssues(int openIssues) {
+            this.openIssues = openIssues;
+            return this;
+        }
+
+        public Builder latestCommit(@Nullable Date latestCommit) {
+            this.latestCommit = latestCommit;
+            return this;
+        }
+
+        public Repository build() {
+            return new Repository(this);
+        }
+    }
+}

src/main/java/world/bentobox/bentobox/api/github/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * Contains objects and classes to get, retrieve and store data from GitHub.
+ * @since 1.3.0
+ */
+package world.bentobox.bentobox.api.github;