Move code from drools-apps to common

Extracted code from ControlLoopUtils to create a new class in
common, PropertyObjectUtils.
Fixed a deprecated method invocation in a junit.
Fixed an object casting (i.e., sonar) issue in SCO.

Issue-ID: POLICY-2305
Signed-off-by: Jim Hahn <jrh3@att.com>
Change-Id: I331a47297f67097ea6986be125ef93cd1954b5ff

1 files changed, 243 insertions, 0 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/properties/PropertyObjectUtils.java b/utils/src/main/java/org/onap/policy/common/utils/properties/PropertyObjectUtils.java
new file mode 100644
index 00000000..996f1b87
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/properties/PropertyObjectUtils.java
@@ -0,0 +1,243 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2019-2020 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.properties;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Utilities for generating POJOs from Properties.
+ */
+public class PropertyObjectUtils {
+
+    public static final Logger logger = LoggerFactory.getLogger(PropertyObjectUtils.class);
+    private static final Pattern NAME_PAT = Pattern.compile("\\[(\\d{1,3})\\]$");
+
+    private PropertyObjectUtils() {
+        // do nothing
+    }
+
+    /**
+     * Converts a set of properties to a Map. Supports json-path style property names with
+     * "." separating components, where components may have an optional subscript.
+     *
+     * @param properties properties to be converted
+     * @param prefix properties whose names begin with this prefix are included. The
+     *        prefix is stripped from the name before adding the value to the map
+     * @return a hierarchical map representing the properties
+     */
+    public static Map<String, Object> toObject(Properties properties, String prefix) {
+        String dottedPrefix = prefix + (prefix.isEmpty() || prefix.endsWith(".") ? "" : ".");
+        int pfxlen = dottedPrefix.length();
+
+        Map<String, Object> map = new LinkedHashMap<>();
+
+        for (String name : properties.stringPropertyNames()) {
+            if (name.startsWith(dottedPrefix)) {
+                String[] components = name.substring(pfxlen).split("[.]");
+                setProperty(map, components, properties.getProperty(name));
+            }
+        }
+
+        return map;
+    }
+
+    /**
+     * Sets a property within a hierarchical map.
+     *
+     * @param map map into which the value should be placed
+     * @param names property name components
+     * @param value value to be placed into the map
+     */
+    private static void setProperty(Map<String, Object> map, String[] names, String value) {
+        Map<String, Object> node = map;
+
+        final int lastComp = names.length - 1;
+
+        // process all but the final component
+        for (int comp = 0; comp < lastComp; ++comp) {
+            node = getNode(node, names[comp]);
+        }
+
+        // process the final component
+        String name = names[lastComp];
+        Matcher matcher = NAME_PAT.matcher(name);
+
+        if (!matcher.find()) {
+            // no subscript
+            node.put(name, value);
+            return;
+        }
+
+        // subscripted
+        List<Object> array = getArray(node, name.substring(0, matcher.start()));
+        int index = Integer.parseInt(matcher.group(1));
+        expand(array, index);
+        array.set(index, value);
+    }
+
+    /**
+     * Gets a node.
+     *
+     * @param map map from which to get the object
+     * @param name name of the element to get from the map, with an optional subscript
+     * @return a Map
+     */
+    @SuppressWarnings("unchecked")
+    private static Map<String, Object> getNode(Map<String, Object> map, String name) {
+        Matcher matcher = NAME_PAT.matcher(name);
+
+        if (!matcher.find()) {
+            // no subscript
+            return getObject(map, name);
+        }
+
+        // subscripted
+        List<Object> array = getArray(map, name.substring(0, matcher.start()));
+        int index = Integer.parseInt(matcher.group(1));
+        expand(array, index);
+
+        Object item = array.get(index);
+        if (item instanceof Map) {
+            return (Map<String, Object>) item;
+
+        } else {
+            LinkedHashMap<String, Object> result = new LinkedHashMap<>();
+            array.set(index, result);
+            return result;
+        }
+    }
+
+    /**
+     * Ensures that an array's size is large enough to hold the specified element.
+     *
+     * @param array array to be expanded
+     * @param index index of the desired element
+     */
+    private static void expand(List<Object> array, int index) {
+        while (array.size() <= index) {
+            array.add(null);
+        }
+    }
+
+    /**
+     * Gets an object (i.e., Map) from a map. If the particular element is not a Map, then
+     * it is replaced with an empty Map.
+     *
+     * @param map map from which to get the object
+     * @param name name of the element to get from the map, without any subscript
+     * @return a Map
+     */
+    private static Map<String, Object> getObject(Map<String, Object> map, String name) {
+        @SuppressWarnings("unchecked")
+        Map<String, Object> result = (Map<String, Object>) map.compute(name, (key, value) -> {
+            if (value instanceof Map) {
+                return value;
+            } else {
+                return new LinkedHashMap<>();
+            }
+        });
+
+        return result;
+    }
+
+    /**
+     * Gets an array from a map. If the particular element is not an array, then it is
+     * replaced with an empty array.
+     *
+     * @param map map from which to get the array
+     * @param name name of the element to get from the map, without any subscript
+     * @return an array
+     */
+    private static List<Object> getArray(Map<String, Object> map, String name) {
+        @SuppressWarnings("unchecked")
+        List<Object> result = (List<Object>) map.compute(name, (key, value) -> {
+            if (value instanceof List) {
+                return value;
+            } else {
+                return new ArrayList<>();
+            }
+        });
+
+        return result;
+    }
+
+    /**
+     * Compresses lists contained within a generic object, removing all {@code null}
+     * items.
+     *
+     * @param object object to be compressed
+     * @return the original object, modified in place
+     */
+    public static Object compressLists(Object object) {
+        if (object instanceof Map) {
+            @SuppressWarnings("unchecked")
+            Map<String, Object> asMap = (Map<String, Object>) object;
+            compressMapValues(asMap);
+
+        } else if (object instanceof List) {
+            @SuppressWarnings("unchecked")
+            List<Object> asList = (List<Object>) object;
+            compressListItems(asList);
+        }
+
+        // else: ignore anything else
+
+        return object;
+    }
+
+    /**
+     * Walks a hierarchical map and removes {@code null} items found in any Lists.
+     *
+     * @param map map whose lists are to be compressed
+     */
+    private static void compressMapValues(Map<String, Object> map) {
+        for (Object value : map.values()) {
+            compressLists(value);
+        }
+    }
+
+    /**
+     * Removes {@code null} items from the list. In addition, it walks the items within
+     * the list, compressing them, as well.
+     *
+     * @param list the list to be compressed
+     */
+    private static void compressListItems(List<Object> list) {
+        Iterator<Object> iter = list.iterator();
+        while (iter.hasNext()) {
+            Object item = iter.next();
+            if (item == null) {
+                // null item - remove it
+                iter.remove();
+
+            } else {
+                compressLists(item);
+            }
+        }
+    }
+}