Merge "Add common coder classes"

3 files changed, 174 insertions, 0 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java
new file mode 100644
index 00000000..41db218b
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java
@@ -0,0 +1,46 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP PAP
+ * ================================================================================
+ * Copyright (C) 2019 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.coder;
+
+/**
+ * JSON encoder and decoder.
+ */
+public interface Coder {
+
+    /**
+     * Encodes an object into json.
+     *
+     * @param object object to be encoded
+     * @return a json string representing the object
+     * @throws CoderException if an error occurs
+     */
+    String encode(Object object) throws CoderException;
+
+    /**
+     * Decodes a json string into an object.
+     *
+     * @param json json string to be decoded
+     * @param clazz class of object to be decoded
+     * @return the object represented by the given json string
+     * @throws CoderException if an error occurs
+     */
+    <T> T decode(String json, Class<T> clazz) throws CoderException;
+}
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/CoderException.java b/utils/src/main/java/org/onap/policy/common/utils/coder/CoderException.java
new file mode 100644
index 00000000..60e85733
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/CoderException.java
@@ -0,0 +1,44 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP PAP
+ * ================================================================================
+ * Copyright (C) 2019 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.coder;
+
+/**
+ * Exceptions generated by coders.
+ */
+public class CoderException extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    public CoderException() {
+        super();
+    }
+
+    public CoderException(String message) {
+        super(message);
+    }
+
+    public CoderException(Throwable cause) {
+        super(cause);
+    }
+
+    public CoderException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java
new file mode 100644
index 00000000..4c7a55c2
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java
@@ -0,0 +1,84 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP PAP
+ * ================================================================================
+ * Copyright (C) 2019 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.coder;
+
+import com.google.gson.Gson;
+
+/**
+ * JSON encoder and decoder using the "standard" mechanism, which is currently gson.
+ */
+public class StandardCoder implements Coder {
+
+    /**
+     * Gson object used to encode and decode messages.
+     */
+    private static final Gson GSON = new Gson();
+
+    /**
+     * Constructs the object.
+     */
+    public StandardCoder() {
+        super();
+    }
+
+    @Override
+    public String encode(Object object) throws CoderException {
+        try {
+            return toJson(object);
+
+        } catch (RuntimeException e) {
+            throw new CoderException(e);
+        }
+    }
+
+    @Override
+    public <T> T decode(String json, Class<T> clazz) throws CoderException {
+        try {
+            return fromJson(json, clazz);
+
+        } catch (RuntimeException e) {
+            throw new CoderException(e);
+        }
+    }
+
+    // the remaining methods are wrappers that can be overridden by junit tests
+
+    /**
+     * Encodes an object into json, without catching exceptions.
+     *
+     * @param object object to be encoded
+     * @return a json string representing the object
+     */
+    protected String toJson(Object object) {
+        return GSON.toJson(object);
+    }
+
+    /**
+     * Decodes a json string into an object, without catching exceptions.
+     *
+     * @param json json string to be decoded
+     * @param clazz class of object to be decoded
+     * @return the object represented by the given json string
+     */
+    protected <T> T fromJson(String json, Class<T> clazz) {
+        return GSON.fromJson(json, clazz);
+    }
+}