1 files changed, 86 insertions, 0 deletions
diff --git a/model/src/main/java/org/onap/policy/apex/model/utilities/comparison/KeyDifference.java b/model/src/main/java/org/onap/policy/apex/model/utilities/comparison/KeyDifference.java
new file mode 100644
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+++ b/model/src/main/java/org/onap/policy/apex/model/utilities/comparison/KeyDifference.java
@@ -0,0 +1,86 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities.comparison;
+
+import lombok.Getter;
+
+/**
+ * This class is used to template key differences for bulk key comparisons in models. It performs a difference check
+ * between two keys.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ * @param <K> the generic type
+ */
+@Getter
+public class KeyDifference<K> {
+    // The keys being compared
+    private K leftKey;
+    private K rightKey;
+
+    /**
+     * Constructor used to set the keys being compared.
+     *
+     * @param leftKey the left key that is being compared
+     * @param rightKey the right key that is being compared
+     */
+    public KeyDifference(final K leftKey, final K rightKey) {
+        this.leftKey = leftKey;
+        this.rightKey = rightKey;
+    }
+
+    /**
+     * Checks if the left and right keys are equal.
+     *
+     * @return true, if checks if is equal
+     */
+    public boolean isEqual() {
+        return leftKey.equals(rightKey);
+    }
+
+    /**
+     * Gets a string representation of the difference between the keys.
+     *
+     * @param diffsOnly if set, then a blank string is returned if the keys are equal
+     * @return the difference between the keys as a string
+     */
+    public String asString(final boolean diffsOnly) {
+        var builder = new StringBuilder();
+
+        if (leftKey.equals(rightKey)) {
+            if (!diffsOnly) {
+                builder.append("left key ");
+                builder.append(leftKey);
+                builder.append(" equals right key ");
+                builder.append(rightKey);
+                builder.append('\n');
+            }
+        } else {
+            builder.append("left key ");
+            builder.append(leftKey);
+            builder.append(" and right key ");
+            builder.append(rightKey);
+            builder.append(" differ\n");
+        }
+
+        return builder.toString();
+    }
+}