docs and tidy up

pom.xml

@@ -88,9 +88,9 @@
 			<scope>test</scope>
 		</dependency>
 		<dependency>
-			<groupId>junit</groupId>
+			<groupId>org.junit.jupiter</groupId>
-			<artifactId>junit</artifactId>
+			<artifactId>junit-jupiter-api</artifactId>
-			<version>4.13.2</version>
+			<version>5.12.0</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
@@ -106,6 +106,16 @@
 					<artifactId>maven-invoker-plugin</artifactId>
 					<version>3.9.0</version>
 				</plugin>
+				<plugin>
+					<groupId>org.eclipse.sisu</groupId>
+					<artifactId>sisu-maven-plugin</artifactId>
+					<version>0.9.0.M2</version>
+				</plugin>
+				<plugin>
+					<groupId>org.codehaus.plexus</groupId>
+					<artifactId>plexus-component-metadata</artifactId>
+					<version>2.2.0</version>
+				</plugin>
 			</plugins>
 		</pluginManagement>
 		<plugins>
@@ -132,7 +142,6 @@
 			<plugin>
 				<groupId>org.eclipse.sisu</groupId>
 				<artifactId>sisu-maven-plugin</artifactId>
-				<version>0.3.5</version>
 				<executions>
 					<execution>
 						<id>generate-index</id>
@@ -145,7 +154,6 @@
 			<plugin>
 				<groupId>org.codehaus.plexus</groupId>
 				<artifactId>plexus-component-metadata</artifactId>
-				<version>2.2.0</version>
 				<executions>
 					<execution>
 						<goals>
@@ -210,7 +218,7 @@
 			</build>
 		</profile>
 		<profile>
-			<id>ossrh-release</id>
+			<id>central-publish</id>
 			<build>
 				<plugins>
 					<plugin>
@@ -247,14 +255,13 @@
 						</executions>
 					</plugin>
 					<plugin>
-						<groupId>org.sonatype.plugins</groupId>
+						<groupId>org.sonatype.central</groupId>
-						<artifactId>nexus-staging-maven-plugin</artifactId>
+						<artifactId>central-publishing-maven-plugin</artifactId>
-						<version>1.7.0</version>
+						<version>0.8.0</version>
 						<extensions>true</extensions>
 						<configuration>
-							<serverId>ossrh</serverId>
+							<publishingServerId>central</publishingServerId>
-							<nexusUrl>https://s01.oss.sonatype.org/</nexusUrl>
+							<autoPublish>true</autoPublish>
-							<autoReleaseAfterClose>true</autoReleaseAfterClose>
 						</configuration>
 					</plugin>
 				</plugins>

src/main/java/com/inteligr8/maven/ban/AbstractBanConfiguration.java

@@ -43,6 +43,37 @@ import org.slf4j.LoggerFactory;
 
 import com.inteligr8.maven.model.ArtifactFilter;
 
+/**
+ * This class handles the parsing of the configuration specification supported
+ * by this plugin.  It does not implement the banning execution; just the
+ * collection of configurations to decide what artifacts should be banned.
+ * 
+ * The specification is as follows:
+ * 
+ * ```xml
+ * <configuration>
+ *   <import>
+ *      <file>relative/path/file.xml</file>
+ *      <url>https://host.domain/path/file.xml</url>
+ *      <artifact>domain.host:artifact-id:[1.0,)</artifact>
+ *   </import>
+ *   <includes>
+ *      <artifact>log4j:log4j</artifact>
+ *      <artifact>org.apache.logging:log4j-impl:[,2.16.1)</artifact>
+ *   </includes>
+ *   <excludes>
+ *      <artifact>...</artifact>
+ *   </excludes>
+ * </configuration>
+ * ```
+ * 
+ * The imports are recursively processed under the same specification.  The
+ * included artifacts are the ones that are banned.  Any artifact matching both
+ * includes and excludes will be excluded and therefore NOT banned.
+ * 
+ * The `groupId` and `artifactId` of the standard shorthand Maven `artifact`
+ * nomenclature may use regular expressions.
+ */
 public abstract class AbstractBanConfiguration implements BanConfiguration {
     
     private final Logger logger = LoggerFactory.getLogger(this.getClass());

src/main/java/com/inteligr8/maven/ban/BanConfigurationDownloader.java

@@ -31,10 +31,24 @@ import org.eclipse.aether.impl.VersionRangeResolver;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/**
+ * This class parses the a configuration file that conforms with the
+ * specification defined by this plugin.
+ */
 public class BanConfigurationDownloader extends AbstractBanConfiguration {
     
     private final Logger logger = LoggerFactory.getLogger(this.getClass());
     
+    /**
+     * This constructs the downloader based on an accessible URL.
+     * 
+     * @param session A Maven session object.
+     * @param artifactResolver A Maven Aether artifact resolver service.
+     * @param versionRangeResolver A Maven Aether version range resolver service.
+     * @param url The URL of a ban configuration file.
+     * @throws IOException The file could not be downloaded for any number of reasons.
+     * @throws MojoFailureException The file could not be parsed due to bad formatting or unexpected response.
+     */
     public BanConfigurationDownloader(MavenSession session, ArtifactResolver artifactResolver, VersionRangeResolver versionRangeResolver, String url) throws IOException, MojoFailureException {
         super(session, artifactResolver, versionRangeResolver);
         
@@ -45,7 +59,17 @@ public class BanConfigurationDownloader extends AbstractBanConfiguration {
             throw new MojoFailureException(xppe.getMessage(), xppe);
         }
     }
-    
+
+    /**
+     * This constructs the downloader based on a file object.
+     * 
+     * @param session A Maven session object.
+     * @param artifactResolver A Maven Aether artifact resolver service.
+     * @param versionRangeResolver A Maven Aether version range resolver service.
+     * @param file A file, typically local, though technically may be remote.
+     * @throws IOException The file could not be read for any number of reasons.
+     * @throws MojoFailureException The file could not be parsed due to bad formatting.
+     */
     public BanConfigurationDownloader(MavenSession session, ArtifactResolver artifactResolver, VersionRangeResolver versionRangeResolver, File file) throws IOException, MojoFailureException {
         super(session, artifactResolver, versionRangeResolver);
         
@@ -57,6 +81,14 @@ public class BanConfigurationDownloader extends AbstractBanConfiguration {
         }
     }
     
+    /**
+     * This method loads the configuration from the specified URL.
+     * 
+     * @param url A URL of a ban configuration file.
+     * @return A Maven Plexus XML DOM object.
+     * @throws IOException The file could not be downloaded for any number of reasons.
+     * @throws MojoFailureException The file could not be parsed due to bad formatting or unexpected response.
+     */
     private Xpp3Dom load(URL url) throws IOException, XmlPullParserException {
         InputStream istream = url.openStream();
         BufferedInputStream bistream = new BufferedInputStream(istream, 16384);
@@ -67,7 +99,15 @@ public class BanConfigurationDownloader extends AbstractBanConfiguration {
             bistream.close();
         }
     }
-    
+
+    /**
+     * This method loads the configuration from the specified file.
+     * 
+     * @param file A file, typically local, though technically may be remote.
+     * @return A Maven Plexus XML DOM object.
+     * @throws IOException The file could not be read for any number of reasons.
+     * @throws MojoFailureException The file could not be parsed due to bad formatting.
+     */
     private Xpp3Dom load(File file) throws IOException, XmlPullParserException {
         FileInputStream fistream = new FileInputStream(file);
         BufferedInputStream bistream = new BufferedInputStream(fistream, 16384);

src/main/java/com/inteligr8/maven/ban/BanDependencyFilter.java

@@ -28,6 +28,18 @@ import org.slf4j.LoggerFactory;
 
 import com.inteligr8.maven.model.ArtifactFilter;
 
+/**
+ * This class implements the banned artifact detection logic.
+ * 
+ * It will recursively scan every dependency and plugin dependency to find any
+ * artifacts that reference a banned artifact and its banned versions.  If one
+ * is found, the filter will fail and stop the build immediately.  It will
+ * prevent the banned artifact from being downloaded.
+ * 
+ * The complicated part is that when multiple versions of the same artifact
+ * show up in the dependency tree, only one may be selected.  So this filter
+ * will ignore the versions that are not selected.
+ */
 public class BanDependencyFilter implements DependencyFilter {
     
     private final Logger logger = LoggerFactory.getLogger(this.getClass());

src/main/java/com/inteligr8/maven/ban/BanExtension.java

@@ -87,7 +87,9 @@ public class BanExtension extends AbstractMavenLifecycleParticipant {
         if (config == null)
             return;
         
-        BanDependencyFilter depFilter = new BanDependencyFilter(config.getIncludeArtifacts(), config.getExcludeArtifacts());
+        BanDependencyFilter depFilter = new BanDependencyFilter(
+                config.getIncludeArtifacts(),
+                config.getExcludeArtifacts());
         depFilter.setFailFast(true);
 
         MavenProject project = session.getCurrentProject();
@@ -132,7 +134,7 @@ public class BanExtension extends AbstractMavenLifecycleParticipant {
             return null;
         } else {
             try {
-                return new BanConfigurationParser(session, this.artifactResolver, this.versionRangeResolver, plugin);
+                return new BanPluginConfigurationParser(session, this.artifactResolver, this.versionRangeResolver, plugin);
             } catch (IOException | MojoFailureException e) {
                 throw new MavenExecutionException(e.getMessage(), project.getFile());
             }

src/main/java/com/inteligr8/maven/ban/BanPluginConfigurationParser.java

@@ -23,9 +23,14 @@ import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.eclipse.aether.impl.ArtifactResolver;
 import org.eclipse.aether.impl.VersionRangeResolver;
 
-public class BanConfigurationParser extends AbstractBanConfiguration {
+/**
+ * This class parses the POM plugin configuration block for this plugin.  The
+ * specification for that configuration block is shared with the one found in
+ * the ban configuration file.
+ */
+public class BanPluginConfigurationParser extends AbstractBanConfiguration {
     
-    public BanConfigurationParser(MavenSession session, ArtifactResolver artifactResolver, VersionRangeResolver versionRangeResolver, Plugin plugin) throws IOException, MojoFailureException {
+    public BanPluginConfigurationParser(MavenSession session, ArtifactResolver artifactResolver, VersionRangeResolver versionRangeResolver, Plugin plugin) throws IOException, MojoFailureException {
         super(session, artifactResolver, versionRangeResolver);
         
         Xpp3Dom rootDom = (Xpp3Dom) plugin.getConfiguration();

src/main/java/com/inteligr8/maven/ban/PurgeRepoMojo.java

@@ -88,7 +88,7 @@ public class PurgeRepoMojo extends AbstractMojo {
     private void purge() throws MojoFailureException, IOException {
         List<Path> includePaths = new LinkedList<>();
         
-        BanConfigurationParser config = this.getConfiguration();
+        BanPluginConfigurationParser config = this.getConfiguration();
         
         for (ArtifactFilter afilter : config.getIncludeArtifacts()) {
             if (afilter.getGroupId() == null) {
@@ -172,12 +172,12 @@ public class PurgeRepoMojo extends AbstractMojo {
         }
 	}
     
-    private BanConfigurationParser getConfiguration() throws MojoFailureException, IOException {
+    private BanPluginConfigurationParser getConfiguration() throws MojoFailureException, IOException {
         MavenProject project = this.session.getCurrentProject();
         Plugin plugin = project.getPlugin(BanExtension.THIS_PLUGIN_KEY);
         if (plugin == null)
             throw new MojoFailureException("The plugin is executing but it cannot be found");
-        return new BanConfigurationParser(this.session, this.artifactResolver, this.versionRangeResolver, plugin);
+        return new BanPluginConfigurationParser(this.session, this.artifactResolver, this.versionRangeResolver, plugin);
     }
     
     private Path resolveGroupPath(ArtifactFilter afilter) {