Add semantic version comparable class

Class written by Jim Hahn that implements Comparable for comparing
semantic versions. Lifted from policy models pap.

Issue-ID: POLICY-1095
Change-Id: Ie8c5f9066c06cb569085e1390b3de3e4aa580267
Signed-off-by: liamfallon <liam.fallon@est.tech>

1 files changed, 113 insertions, 0 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/validation/Version.java b/utils/src/main/java/org/onap/policy/common/utils/validation/Version.java
new file mode 100644
index 00000000..b5769948
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/validation/Version.java
@@ -0,0 +1,113 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP COMMON
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * Modifications Copyright (C) 2019 Nordix Foundation.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.validation;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.RequiredArgsConstructor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Version of an object within the model. Versions are assumed to be of the form: major or
+ * major.minor.patch, where each component is numeric.
+ */
+@Data
+@RequiredArgsConstructor
+@NoArgsConstructor(force = true)
+public class Version implements Comparable<Version> {
+    private static final Logger logger = LoggerFactory.getLogger(Version.class);
+
+    /**
+     * Pattern to match a version of the form, major or major.minor.patch, where all
+     * components are numeric.
+     */
+    private static final Pattern VERSION_PAT = Pattern.compile("(\\d+)([.](\\d+)[.](\\d+))?");
+
+    private final int major;
+    private final int minor;
+    private final int patch;
+
+
+    /**
+     * Creates a version object.
+     *
+     * @param type type of object with which the version is associated, used when logging
+     * @param name name with which the version is associated, used when logging
+     * @param versionText the version, in textual form
+     * @return a new version, or {@code null} if the version cannot be created from the
+     *         key (e.g., the key has a version that does not match the major.minor.patch
+     *         form)
+     */
+    public static Version makeVersion(String type, String name, String versionText) {
+        Matcher matcher = VERSION_PAT.matcher(versionText);
+        if (!matcher.matches()) {
+            logger.info("invalid version for {} {}: {}", type, name, versionText);
+            return null;
+        }
+
+        try {
+            if (matcher.group(2) == null) {
+                // form: major
+                return new Version(Integer.parseInt(matcher.group(1)), 0, 0);
+
+            } else {
+                // form: major.minor.patch
+                return new Version(Integer.parseInt(matcher.group(1)), Integer.parseInt(matcher.group(3)),
+                                Integer.parseInt(matcher.group(4)));
+            }
+
+        } catch (NumberFormatException e) {
+            logger.info("invalid version for {} {}: {}", type, name, versionText, e);
+            return null;
+        }
+    }
+
+    /**
+     * Generates a new version from the current version.
+     *
+     * @return a new version, of the form major.0.0, where "major" is one more than "this"
+     *         version's major number
+     */
+    public Version newVersion() {
+        return new Version(major + 1, 0, 0);
+    }
+
+    @Override
+    public int compareTo(Version other) {
+        int result = Integer.compare(major, other.major);
+        if (result != 0) {
+            return result;
+        }
+        if ((result = Integer.compare(minor, other.minor)) != 0) {
+            return result;
+        }
+        return Integer.compare(patch, other.patch);
+    }
+
+    @Override
+    public String toString() {
+        return major + "." + minor + "." + patch;
+    }
+}
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