1 files changed, 95 insertions, 0 deletions
diff --git a/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/loader/classpath/ManifestPackageAttributes.java b/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/loader/classpath/ManifestPackageAttributes.java
new file mode 100644
index 000000000..1143a1207
--- /dev/null
+++ b/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/loader/classpath/ManifestPackageAttributes.java
@@ -0,0 +1,95 @@
+/******************************************************************************
+ * Copyright (c) 2016 Alex Blewitt and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Alex Blewitt - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.osgi.internal.loader.classpath;
+
+/**
+ * Stores a pair of {@link TitleVersionVendor} package attributes for the Implementation- and Specification- entries.
+ */
+class ManifestPackageAttributes {
+	/**
+	 * Constant used when no titles, versions or vendors are specified for the package.
+	 */
+	static final ManifestPackageAttributes NONE = new ManifestPackageAttributes(TitleVersionVendor.NONE, TitleVersionVendor.NONE);
+	private final TitleVersionVendor implementation;
+	private final TitleVersionVendor specification;
+
+	/**
+	 * Utility method to return the first version, or the second if it is null
+	 * @param first the string to return if not null
+	 * @param second the fallback value if the first is null
+	 * @return the first value, or the second value if the first is null
+	 */
+	private static String or(String first, String second) {
+		return first == null ? second : first;
+	}
+
+	/**
+	 * Factory method for creating ManifestPackageAttributes.  If any of the given title,
+	 * version, or vendor values are <code>null</code> then the defaultAttributes will be
+	 * used.  If the defaultAttributes is null or returns all <code>null</code> values then
+	 * <code>null</code> values will be used.  If <code>null</code> values are used for all of the 
+	 * versions, titles, and vendors then {@link #NONE} is returned. 
+	 * @param specificationTitle the package specification title
+	 * @param specificationVersion the package specification version
+	 * @param specificationVendor the package specification vendor
+	 * @param implementationTitle the package implementation title
+	 * @param implementationVersion the package implementation version
+	 * @param implementationVendor the package implementation vendor
+	 * @param defaultAttributes the default attributes to use when the specified title, version or vendor is <code>null</code>.
+	 * @return
+	 */
+	static ManifestPackageAttributes of(String specificationTitle, String specificationVersion, String specificationVendor, String implementationTitle, String implementationVersion, String implementationVendor, ManifestPackageAttributes defaultAttributes) {
+		if (defaultAttributes == null) {
+			defaultAttributes = NONE;
+		}
+		return of(//
+				or(specificationTitle, defaultAttributes.getSpecification().getTitle()), //
+				or(specificationVersion, defaultAttributes.getSpecification().getVersion()), //
+				or(specificationVendor, defaultAttributes.getSpecification().getVendor()), //
+				or(implementationTitle, defaultAttributes.getImplementation().getTitle()), //
+				or(implementationVersion, defaultAttributes.getImplementation().getVersion()), //
+				or(implementationVendor, defaultAttributes.getImplementation().getVendor())//
+		);
+	}
+
+	private static ManifestPackageAttributes of(String specificationTitle, String specificationVersion, String specificationVendor, String implementationTitle, String implementationVersion, String implementationVendor) {
+		TitleVersionVendor specification = TitleVersionVendor.of(specificationTitle, specificationVersion, specificationVendor);
+		TitleVersionVendor implementation = TitleVersionVendor.of(implementationTitle, implementationVersion, implementationVendor);
+		if (specification == TitleVersionVendor.NONE && implementation == TitleVersionVendor.NONE) {
+			return NONE;
+		}
+		return new ManifestPackageAttributes(implementation, specification);
+	}
+
+	private ManifestPackageAttributes(TitleVersionVendor implementation, TitleVersionVendor specification) {
+		if (implementation == null || specification == null) {
+			throw new IllegalArgumentException();
+		}
+		this.implementation = implementation;
+		this.specification = specification;
+	}
+
+	/**
+	 * Returns the title, version and vendor for the package implementation.
+	 * @return the title, version and vendor for the package implemetnation.
+	 */
+	TitleVersionVendor getImplementation() {
+		return implementation;
+	}
+
+	/**
+	 * Returns the title, version and vendor for the package specification.
+	 * @return the title, version and vendor for the package specification.
+	 */
+	TitleVersionVendor getSpecification() {
+		return specification;
+	}
+}