Add common coder classes

Added coder classes as a common utility that can be used to encode
and decode json data.  Currently, it uses gson, but that can be
changed.

Separated the Coder interface from implementation.

Used assertSame to compare references.
Used numbers instead of strings so don't have to deal with escaping quotes
in the test cases.

Change-Id: Iea9001d2adc5a3150b3367619b5f43e96b5f8b41
Issue-ID: POLICY-1444
Signed-off-by: Jim Hahn <jrh3@att.com>

2 files changed, 145 insertions, 0 deletions

diff --git a/utils/src/test/java/org/onap/policy/common/utils/coder/CoderExceptionTest.java b/utils/src/test/java/org/onap/policy/common/utils/coder/CoderExceptionTest.java
new file mode 100644
index 00000000..cecc4265
--- /dev/null
+++ b/utils/src/test/java/org/onap/policy/common/utils/coder/CoderExceptionTest.java
@@ -0,0 +1,72 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * 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 static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class CoderExceptionTest {
+    private static final String STRING_VALUE = "My String";
+    private static final Throwable CAUSE = new Throwable();
+
+    private CoderException exc;
+
+    @Test
+    public void testCoderException() {
+        exc = new CoderException();
+
+        assertEquals(null, exc.getMessage());
+        assertSame(null, exc.getCause());
+        assertNotNull(exc.toString());
+    }
+
+    @Test
+    public void testCoderExceptionString() {
+        exc = new CoderException(STRING_VALUE);
+
+        assertEquals(STRING_VALUE, exc.getMessage());
+        assertSame(null, exc.getCause());
+        assertTrue(exc.toString().contains(STRING_VALUE));
+    }
+
+    @Test
+    public void testCoderExceptionThrowable() {
+        exc = new CoderException(CAUSE);
+
+        assertEquals(CAUSE.toString(), exc.getMessage());
+        assertSame(CAUSE, exc.getCause());
+        assertNotNull(exc.toString());
+    }
+
+    @Test
+    public void testCoderExceptionStringThrowable() {
+        exc = new CoderException(STRING_VALUE, CAUSE);
+
+        assertEquals(STRING_VALUE, exc.getMessage());
+        assertSame(CAUSE, exc.getCause());
+        assertTrue(exc.toString().contains(STRING_VALUE));
+    }
+
+}
diff --git a/utils/src/test/java/org/onap/policy/common/utils/coder/StandardCoderTest.java b/utils/src/test/java/org/onap/policy/common/utils/coder/StandardCoderTest.java
new file mode 100644
index 00000000..80157d02
--- /dev/null
+++ b/utils/src/test/java/org/onap/policy/common/utils/coder/StandardCoderTest.java
@@ -0,0 +1,73 @@
+/*
+ * ============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 static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.when;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParseException;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Before;
+import org.junit.Test;
+
+public class StandardCoderTest {
+
+    private StandardCoder coder;
+
+    @Before
+    public void setUp() {
+        coder = new StandardCoder();
+    }
+
+    @Test
+    public void testEncode() throws Exception {
+        List<Integer> arr = Arrays.asList(100, 110);
+        assertEquals("[100,110]", coder.encode(arr));
+
+        // test exception case
+        JsonParseException jpe = new JsonParseException("expected exception");
+
+        coder = spy(coder);
+        when(coder.toJson(arr)).thenThrow(jpe);
+
+        assertThatThrownBy(() -> coder.encode(arr)).isInstanceOf(CoderException.class).hasCause(jpe);
+    }
+
+    @Test
+    public void testDecode() throws Exception {
+        String text = "[200,210]";
+        assertEquals(text, coder.decode(text, JsonElement.class).toString());
+
+        // test exception case
+        JsonParseException jpe = new JsonParseException("expected exception");
+
+        coder = spy(coder);
+        when(coder.fromJson(text, JsonElement.class)).thenThrow(jpe);
+
+        assertThatThrownBy(() -> coder.decode(text, JsonElement.class)).isInstanceOf(CoderException.class)
+                        .hasCause(jpe);
+    }
+
+}