Merge "Add common coder classes"

5 files changed, 319 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);
+    }
+}
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);
+    }
+
+}