Mods for Java 8 and for new getOptionalXyz() methods (#127).

Author: gmessner

pom.xml

@@ -5,7 +5,7 @@
 	<groupId>org.gitlab4j</groupId>
 	<artifactId>gitlab4j-api</artifactId>
 	<packaging>jar</packaging>
-	<version>4.7.18-SNAPSHOT</version>
+	<version>4.8.0-SNAPSHOT</version>
 	<name>GitLab API Java Client</name>
 	<description>GitLab API for Java (gitlab4j-api) provides a full featured Java API for working with GitLab repositories via the GitLab REST API.</description>
 	<url>https://github.com/gmessner/gitlab4j-api</url>
@@ -38,7 +38,8 @@
 	</developers>
 
 	<properties>
-		<jdk.version>1.7</jdk.version>
+        <java.source.version>1.8</java.source.version>
+        <java.target.version>1.8</java.target.version>
 		<jersey.version>2.26</jersey.version>
 		<jackson.version>2.9.3</jackson.version>
 		<javaServlet.version>3.1.0</javaServlet.version>
@@ -60,15 +61,15 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-release-plugin</artifactId>
-				<version>2.5.1</version>
+				<version>2.5.3</version>
 				<configuration>
 					<goals>deploy</goals>
 				</configuration>
 			</plugin>
 
 			<plugin>
 				<artifactId>maven-scm-plugin</artifactId>
-				<version>1.9.2</version>
+				<version>1.9.5</version>
 				<configuration>
 					<tag>${project.artifactId}-${project.version}</tag>
 				</configuration>
@@ -77,17 +78,27 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
-				<version>3.2</version>
+				<version>3.7.0</version>
 				<configuration>
-					<source>${jdk.version}</source>
-					<target>${jdk.version}</target>
+					<source>${java.source.version}</source>
+					<target>${java.target.version}</target>
 				</configuration>
+				<executions>
+					<execution>
+						<id>default-compile</id>
+						<configuration>
+							<excludes>
+								<exclude>**/module-info.java</exclude>
+							</excludes>
+						</configuration>
+					</execution>
+				</executions>
 			</plugin>
 
-			<plugin>
+            <plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-gpg-plugin</artifactId>
-				<version>1.5</version>
+				<version>1.6</version>
 				<executions>
 					<execution>
 						<id>sign-artifacts</id>
@@ -102,7 +113,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-source-plugin</artifactId>
-				<version>2.4</version>
+				<version>3.0.0</version>
 				<executions>
 					<execution>
 						<id>attach-sources</id>
@@ -116,7 +127,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-javadoc-plugin</artifactId>
-				<version>2.10.1</version>
+				<version>3.0.0</version>
 				<executions>
 					<execution>
 						<id>attach-javadocs</id>
@@ -130,7 +141,7 @@
 			<plugin>
 				<groupId>org.jacoco</groupId>
 				<artifactId>jacoco-maven-plugin</artifactId>
-				<version>0.7.9</version>
+				<version>0.8.0</version>
 				<executions>
 					<execution>
 						<id>default-prepare-agent</id>
@@ -173,7 +184,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
-				<version>2.12.2</version>
+				<version>2.19.1</version>
 				<configuration>
 					<systemPropertyVariables>
 						<jacoco-agent.destfile>target/jacoco.exec</jacoco-agent.destfile>
@@ -184,6 +195,7 @@
 	</build>
 
 	<dependencies>
+		<!-- jaxb-api and javax.activation added for Java 9 compatibility -->
 		<dependency>
 			<groupId>javax.xml.bind</groupId>
 			<artifactId>jaxb-api</artifactId>
@@ -194,6 +206,7 @@
 			<artifactId>javax.activation</artifactId>
 			<version>1.2.0</version>
 		</dependency>
+
 		<dependency>
 			<groupId>com.fasterxml.jackson.jaxrs</groupId>
 			<artifactId>jackson-jaxrs-json-provider</artifactId>

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

@@ -1,6 +1,9 @@
 package org.gitlab4j.api;
 
+import java.util.Collections;
 import java.util.Map;
+import java.util.Optional;
+import java.util.WeakHashMap;
 
 import javax.ws.rs.core.Response;
 
@@ -28,6 +31,10 @@ public String getApiNamespace() {
         }
     }
 
+    // Used to keep track of GitLabApiExceptions on calls that return Optionsl<?>
+    private static final Map<Optional<?>, GitLabApiException> optionalExceptionMap =
+            Collections.synchronizedMap(new WeakHashMap<Optional<?>, GitLabApiException>());
+
     GitLabApiClient apiClient;
     private ApiVersion apiVersion;
     private String gitLabServerUrl;
@@ -55,7 +62,6 @@ public String getApiNamespace() {
     private NotesApi notesApi;
     private EventsApi eventsApi;
 
-
     /**
      * Create a new GitLabApi instance that is logically a duplicate of this instance, with the exception off sudo state.
      *
@@ -993,4 +999,46 @@ public UserApi getUserApi() {
 
         return (userApi);
     }
+
+    /**
+     * Create and return an Optional instance associated with a GitLabApiException.
+     *
+     * @param optional the Optional instance to use as the key for the exception
+     * @param glae the GitLabApiException that was the result of a call to the GitLab API 
+     */
+    protected static final <T> Optional<T> createOptionalFromException(GitLabApiException glae) {
+        Optional<T> optional = Optional.empty();
+        optionalExceptionMap.put(optional,  glae);
+        return (optional);
+    }
+
+    /**
+     * Get the exception associated with the provided Optional instance, or null if no exception is
+     * associated with the Optional instance.
+     *
+     * @param optional the Optional instance to get the exception for
+     * @return the exception associated with the provided Optional instance, or null if no exception is
+     * associated with the Optional instance
+     */
+    public static final GitLabApiException getOptionalException(Optional<?> optional) {
+        return (optionalExceptionMap.get(optional));
+    }
+
+    /**
+     * Return the Optional instances contained value, if present, otherwise throw the exception that is
+     * associated with the Optional instance.
+     *
+     * @param optional the Optional instance to get the value for
+     * @return the value of the Optional instance if no exception is associated with it
+     * @throws GitLabApiException if there was an exception associated with the Optional instance
+     */
+    public static final <T> T orElseThrow(Optional<T> optional) throws GitLabApiException {
+
+        GitLabApiException glea = getOptionalException(optional);
+        if (glea != null) {
+            throw (glea);
+        }
+
+        return (optional.get());
+    }
 }

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

@@ -2,6 +2,7 @@
 
 import java.util.Date;
 import java.util.List;
+import java.util.Optional;
 
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
@@ -12,7 +13,6 @@
 import org.gitlab4j.api.models.Group;
 import org.gitlab4j.api.models.Member;
 import org.gitlab4j.api.models.Project;
-import org.gitlab4j.api.models.User;
 import org.gitlab4j.api.models.Visibility;
 
 /**
@@ -281,6 +281,18 @@ public Group getGroup(Integer groupId) throws GitLabApiException {
         return getGroup(groupId.toString());
     }
 
+    /**
+     * Get all details of a group as an Optional instance.
+     *
+     * GET /groups/:id
+     *
+     * @param groupId the group ID to get
+     * @return the Group for the specified group ID as an Optional instance
+     */
+    public Optional<Group> getOptionalGroup(Integer groupId) {
+        return (getOptionalGroup(groupId.toString()));
+    }
+
     /**
      * Get all details of a group.
      *
@@ -295,6 +307,22 @@ public Group getGroup(String groupPath) throws GitLabApiException {
       return (response.readEntity(Group.class));
     }
 
+    /**
+     * Get all details of a group as an Optional instance.
+     *
+     * GET /groups/:id
+     *
+     * @param groupPath the path of the group to get details for
+     * @return the Group for the specified group path as an Optional instance
+     */
+    public Optional<Group> getOptionalGroup(String groupPath) {
+        try {
+            return (Optional.ofNullable(getGroup(groupPath)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
     /**
      * Creates a new project group. Available only for users who can create groups.
      *
@@ -543,6 +571,23 @@ public Member getMember(int groupId, int userId) throws GitLabApiException {
         return (response.readEntity(new GenericType<Member>() {}));
     }
 
+    /**
+     * Get a group member viewable by the authenticated user as an Optional instance.
+     *
+     * GET /groups/:id/members/:id
+     *
+     * @param groupId the group ID to get the member for
+     * @param userId the member ID of the member to get
+     * @return a member viewable by the authenticated user as an Optional instance
+     */
+    public Optional<Member> getOptionalMember(int groupId, int userId) throws GitLabApiException {
+        try {
+            return (Optional.ofNullable(getMember(groupId, userId)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
     /**
      * Adds a user to the list of group members.
      *