implementing the purge feature as requested in issue #328

dependency-check-maven/src/main/java/org/owasp/dependencycheck/maven/BaseDependencyCheckMojo.java

@@ -233,6 +233,15 @@ public abstract class BaseDependencyCheckMojo extends AbstractMojo implements Ma
      */
     @Parameter(property = "connectionString", defaultValue = "", required = false)
     private String connectionString;
+
+    /**
+     * Returns the connection string.
+     *
+     * @return the connection string
+     */
+    protected String getConnectionString() {
+        return connectionString;
+    }
     /**
      * The database driver name. An example would be org.h2.Driver.
      */
@@ -594,7 +603,7 @@ public abstract class BaseDependencyCheckMojo extends AbstractMojo implements Ma
      * Takes the properties supplied and updates the dependency-check settings. Additionally, this sets the system properties
      * required to change the proxy url, port, and connection timeout.
      */
-    private void populateSettings() {
+    protected void populateSettings() {
         Settings.initialize();
         InputStream mojoProperties = null;
         try {

dependency-check-maven/src/main/java/org/owasp/dependencycheck/maven/PurgeMojo.java

@@ -0,0 +1,107 @@
+/*
+ * This file is part of dependency-check-maven.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright (c) 2015 Jeremy Long. All Rights Reserved.
+ */
+package org.owasp.dependencycheck.maven;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Locale;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugins.annotations.LifecyclePhase;
+import org.apache.maven.plugins.annotations.Mojo;
+import org.apache.maven.plugins.annotations.ResolutionScope;
+import org.owasp.dependencycheck.data.nvdcve.DatabaseException;
+import org.owasp.dependencycheck.utils.Settings;
+
+/**
+ * Maven Plugin that purges the local copy of the NVD data.
+ *
+ * @author Jeremy Long
+ */
+@Mojo(
+        name = "purge",
+        defaultPhase = LifecyclePhase.GENERATE_RESOURCES,
+        threadSafe = true,
+        requiresDependencyResolution = ResolutionScope.NONE,
+        requiresOnline = true
+)
+public class PurgeMojo extends BaseDependencyCheckMojo {
+
+    /**
+     * Returns false; this mojo cannot generate a report.
+     *
+     * @return <code>false</code>
+     */
+    @Override
+    public boolean canGenerateReport() {
+        return false;
+    }
+
+    /**
+     * Purges the local copy of the NVD.
+     *
+     * @throws MojoExecutionException thrown if there is an exception executing the goal
+     * @throws MojoFailureException thrown if dependency-check is configured to fail the build
+     */
+    @Override
+    public void runCheck() throws MojoExecutionException, MojoFailureException {
+
+        if (getConnectionString() != null && !getConnectionString().isEmpty()) {
+            getLog().error("Unable to purge the local NVD when using a non-default connection string");
+        } else {
+            populateSettings();
+            File db;
+            try {
+                db = new File(Settings.getDataDirectory(), "dc.h2.db");
+                if (db.exists()) {
+                    if (db.delete()) {
+                        getLog().info("Database file purged; local copy of the NVD has been removed");
+                    } else {
+                        getLog().error(String.format("Unable to delete '%s'; please delete the file manually", db.getAbsolutePath()));
+                    }
+                } else {
+                    getLog().error(String.format("Unable to purge database; the database file does not exists: %s", db.getAbsolutePath()));
+                }
+            } catch (IOException ex) {
+                getLog().error("Unable to delete the database");
+            }
+            Settings.cleanup();
+        }
+    }
+
+    /**
+     * Returns the report name.
+     *
+     * @param locale the location
+     * @return the report name
+     */
+    public String getName(Locale locale) {
+        return "dependency-check-purge";
+    }
+
+    /**
+     * Gets the description of the Dependency-Check report to be displayed in the Maven Generated Reports page.
+     *
+     * @param locale The Locale to get the description for
+     * @return the description
+     */
+    public String getDescription(Locale locale) {
+        return "Purges the local cache of the NVD dataT.";
+    }
+
+}