Merge changes Idbdec7b3,I643dadac,I2f54e1d5,I2ead5203

* changes:
  Provide initial a1-pe-sim docs
  Initial code check-in for A1 Policy Enforcement Simulator
  Add basic .gitignore
  Add linters setup

1 files changed, 99 insertions, 0 deletions

diff --git a/src/main/java/org/onap/a1pesimulator/util/JsonUtils.java b/src/main/java/org/onap/a1pesimulator/util/JsonUtils.java
new file mode 100644
index 0000000..9263bc1
--- /dev/null
+++ b/src/main/java/org/onap/a1pesimulator/util/JsonUtils.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2021 Samsung Electronics
+ * 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
+ */
+
+package org.onap.a1pesimulator.util;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.FileReader;
+import java.io.IOException;
+import java.net.URL;
+import java.text.MessageFormat;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public enum JsonUtils {
+
+    INSTANCE;
+
+    private static final Logger log = LoggerFactory.getLogger(JsonUtils.class);
+
+    private ObjectMapper mapper;
+
+    private JsonUtils() {
+        this.mapper = new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    }
+
+    public String objectToPrettyString(Object object) {
+        try {
+            return mapper.writerWithDefaultPrettyPrinter().writeValueAsString(object);
+        } catch (JsonProcessingException e) {
+            throw new JsonUtilsException("Cannot serialize object", e);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T> T clone(T object) {
+        String stringValue;
+        try {
+            stringValue = mapper.writeValueAsString(object);
+            return (T) mapper.readValue(stringValue, object.getClass());
+        } catch (JsonProcessingException e) {
+            throw new JsonUtilsException("Cannot clone object", e);
+        }
+    }
+
+    public <T> T deserializeFromFile(String fileName, Class<T> clazz) {
+        try {
+            return mapper.readValue(new FileReader(fileName), clazz);
+        } catch (IOException e) {
+            String errorMsg = MessageFormat.format("Could not deserialize from file: {0} into {1}", fileName,
+                    clazz.getSimpleName());
+            log.error(errorMsg, e);
+            throw new JsonUtilsException(errorMsg, e);
+        }
+    }
+
+    public <T> T deserializeFromFileUrl(URL url, Class<T> clazz) {
+        try {
+            return mapper.readValue(url, clazz);
+        } catch (IOException e) {
+            String errorMsg = MessageFormat.format("Could not deserialize from file URL: {0} into {1}", url,
+                    clazz.getSimpleName());
+            log.error(errorMsg, e);
+            throw new JsonUtilsException(errorMsg, e);
+        }
+    }
+
+    public <T> T deserialize(String string, Class<T> clazz) throws JsonUtilsException {
+        try {
+            return mapper.readValue(string, clazz);
+        } catch (IOException e) {
+            String errorMsg = MessageFormat
+                                      .format("Could not deserialize into {0} from object: {1}", clazz.getSimpleName(),
+                                              string);
+            log.error(errorMsg, e);
+            throw new JsonUtilsException(errorMsg, e);
+        }
+    }
+
+    public static class JsonUtilsException extends RuntimeException {
+
+        private static final long serialVersionUID = 1L;
+
+        public JsonUtilsException(String message, Throwable throwable) {
+            super(message, throwable);
+        }
+    }
+}