1 files changed, 99 insertions, 0 deletions
diff --git a/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java b/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
new file mode 100644
index 000000000..e9757eca0
--- /dev/null
+++ b/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
@@ -0,0 +1,99 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.utils;
+
+import com.google.gson.stream.JsonReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.Iterator;
+import java.util.ServiceLoader;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
+import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
+import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
+import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
+import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
+import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import org.opendaylight.yangtools.yang.model.parser.api.YangParser;
+import org.opendaylight.yangtools.yang.model.parser.api.YangParserException;
+import org.opendaylight.yangtools.yang.model.parser.api.YangParserFactory;
+import org.opendaylight.yangtools.yang.model.repo.api.StatementParserMode;
+import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
+
+public class YangUtils {
+
+    private static final YangParserFactory PARSER_FACTORY;
+
+    private YangUtils() {
+        throw new IllegalStateException("Utility class");
+    }
+
+    static {
+        final Iterator<YangParserFactory> it = ServiceLoader.load(YangParserFactory.class).iterator();
+        if (!it.hasNext()) {
+            throw new IllegalStateException("No YangParserFactory found");
+        }
+        PARSER_FACTORY = it.next();
+    }
+
+    /**
+     * Parse a file containing yang modules.
+     * @param yangModelFile  a file containing one or more yang modules
+     *                   (please note the file has to have a .yang extension if not an exception will be thrown)
+     * @return a SchemaContext representing the yang model
+     * @throws IOException when the system as an IO issue
+     * @throws YangParserException when the file does not contain a valid yang structure
+     */
+    public static SchemaContext parseYangModelFile(final File yangModelFile) throws IOException, YangParserException {
+        YangTextSchemaSource yangTextSchemaSource = YangTextSchemaSource.forFile(yangModelFile);
+        final YangParser yangParser = PARSER_FACTORY
+                .createParser(StatementParserMode.DEFAULT_MODE);
+        yangParser.addSource(yangTextSchemaSource);
+        return yangParser.buildEffectiveModel();
+    }
+
+    /**
+     * Parse a file containing json data for a certain model (schemaContext).
+     * @param jsonData a string containing json data for the given model
+     * @param schemaContext the SchemaContext for the given data
+     * @return the NormalizedNode representing the json data
+     */
+    public static NormalizedNode<?, ?> parseJsonData(final String jsonData, final SchemaContext schemaContext)
+            throws IOException {
+        JSONCodecFactory jsonCodecFactory = JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02
+                .getShared(schemaContext);
+        final NormalizedNodeResult normalizedNodeResult = new NormalizedNodeResult();
+        final NormalizedNodeStreamWriter normalizedNodeStreamWriter = ImmutableNormalizedNodeStreamWriter
+                .from(normalizedNodeResult);
+        try (JsonParserStream jsonParserStream = JsonParserStream
+                .create(normalizedNodeStreamWriter, jsonCodecFactory)) {
+            final JsonReader jsonReader = new JsonReader(new StringReader(jsonData));
+            jsonParserStream.parse(jsonReader);
+        }
+        return normalizedNodeResult.getResult();
+    }
+
+    public static void chopNormalizedNode(NormalizedNode<?, ?> tree) {
+        //TODO Toine Siebelink, add code from proto-type (other user story)
+    }
+
+}