add utility class to test serializable classes

Closed the ByteArrayXxxStreams.
Closed byte output stream, even if exception in object stream.

Change-Id: I3f779a5c0e6df3ac3496abe60a46e0696b4e261c
Issue-ID: POLICY-1106
Signed-off-by: Jim Hahn <jrh3@att.com>

2 files changed, 184 insertions, 0 deletions

diff --git a/utils-test/src/main/java/org/onap/policy/common/utils/io/Serializer.java b/utils-test/src/main/java/org/onap/policy/common/utils/io/Serializer.java
new file mode 100644
index 00000000..740aad47
--- /dev/null
+++ b/utils-test/src/main/java/org/onap/policy/common/utils/io/Serializer.java
@@ -0,0 +1,89 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP Policy Engine - Common Modules
+ * ================================================================================
+ * Copyright (C) 2018 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.io;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+/**
+ * Utilities for testing serialization and de-serialization of objects.
+ */
+public class Serializer {
+
+    /**
+     * The constructor.
+     */
+    private Serializer() {
+
+    }
+
+    /**
+     * Serializes an object into a byte array.
+     * 
+     * @param object the object to be serialized
+     * @return the byte array containing the serialized object
+     * @throws IOException if an error occurs
+     */
+    public static <T> byte[] serialize(T object) throws IOException {
+        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+            try (ObjectOutputStream oos = new ObjectOutputStream(out)) {
+                oos.writeObject(object);
+            }
+
+            return out.toByteArray();
+        }
+    }
+
+    /**
+     * De-serializes an object from a byte array.
+     * 
+     * @param clazz class of object that is expected to be de-serialized
+     * @param data the byte array containing the serialized object
+     * @return the object that was de-serialized from the byte array
+     * @throws IOException if an error occurs
+     */
+    public static <T> T deserialize(Class<T> clazz, byte[] data) throws IOException {
+
+        try (ByteArrayInputStream in = new ByteArrayInputStream(data);
+                        ObjectInputStream ois = new ObjectInputStream(in)) {
+            return clazz.cast(ois.readObject());
+
+        } catch (ClassNotFoundException e) {
+            throw new IOException(e);
+        }
+    }
+
+    /**
+     * Runs an object through a complete round trip, serializing and then de-serializing
+     * it.
+     * 
+     * @param object object to be serialized
+     * @return the object that was de-serialized
+     * @throws IOException if an error occurs
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> T roundTrip(T object) throws IOException {
+        return (T) deserialize(object.getClass(), serialize(object));
+    }
+}
diff --git a/utils-test/src/test/java/org/onap/policy/common/utils/io/SerializerTest.java b/utils-test/src/test/java/org/onap/policy/common/utils/io/SerializerTest.java
new file mode 100644
index 00000000..4d4385fc
--- /dev/null
+++ b/utils-test/src/test/java/org/onap/policy/common/utils/io/SerializerTest.java
@@ -0,0 +1,95 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP Policy Engine - Common Modules
+ * ================================================================================
+ * Copyright (C) 2018 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.io;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.Serializable;
+import java.util.Arrays;
+import org.junit.Test;
+
+public class SerializerTest {
+
+    @Test
+    public void testSerialize() throws Exception {
+        MyObject obj1 = new MyObject(3);
+        byte[] data = Serializer.serialize(obj1);
+        assertTrue(data.length > 0);
+
+        byte[] data2 = Serializer.serialize(obj1);
+        assertEquals(Arrays.toString(data), Arrays.toString(data2));
+
+        MyObject obj2 = Serializer.deserialize(MyObject.class, data);
+        assertEquals(obj1.value, obj2.value);
+    }
+
+    @Test(expected = java.io.NotSerializableException.class)
+    public void testSerialize_Ex() throws Exception {
+        Serializer.serialize(new NotSerializable());
+    }
+
+    @Test
+    public void testDeserialize() throws Exception {
+        MyObject obj1 = new MyObject(3);
+        byte[] data = Serializer.serialize(obj1);
+
+        MyObject obj2 = Serializer.deserialize(MyObject.class, data);
+        assertEquals(obj1.value, obj2.value);
+    }
+
+    @Test
+    public void testRoundTrip() throws Exception {
+        MyObject obj1 = new MyObject(3);
+
+        MyObject obj2 = Serializer.roundTrip(obj1);
+        assertEquals(obj1.value, obj2.value);
+    }
+
+    @Test(expected = java.io.NotSerializableException.class)
+    public void testRoundTrip_Ex() throws Exception {
+        Serializer.roundTrip(new NotSerializable());
+    }
+
+    /**
+     * Simple, serializable object.
+     */
+    public static class MyObject implements Serializable {
+        private static final long serialVersionUID = 1L;
+
+        private int value;
+
+        public MyObject(int val) {
+            value = val;
+        }
+    }
+
+    /**
+     * Object that is <i>not</i> serializable.
+     */
+    public static class NotSerializable {
+
+        public NotSerializable() {
+            super();
+        }
+    }
+
+}