Extract YamlJsonTranslator from StandardYamlCoder

Refactored StandardYamlCoder, extracting a new class, YamlJsonTranslator,
from it.  This facilitates performing yaml translation when not using a
standard "gson" coder.
Added YamlJacksonHandler which supports YAML translation layered on
top of a JacksonHandler instead of a GsonMessageBodyHandler.
Also added junit tests to complete coverage of StandardCoder.
Also added public APPLICATION_YAML to YamlMessageBodyHandler.

Change-Id: Ia470fa194661fbf1aebeaf0f18b57f2a984cb64b
Issue-ID: POLICY-2081
Signed-off-by: Jim Hahn <jrh3@att.com>

7 files changed, 540 insertions, 295 deletions

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
index d3d69812..c3f2d993 100644
--- 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
@@ -38,6 +38,8 @@ import java.io.OutputStreamWriter;
 import java.io.Reader;
 import java.io.Writer;
 import java.nio.charset.StandardCharsets;
+import lombok.AccessLevel;
+import lombok.Getter;
 import org.onap.policy.common.gson.DoubleConverter;
 import org.onap.policy.common.gson.MapDoubleAdapterFactory;
 
@@ -49,6 +51,7 @@ public class StandardCoder implements Coder {
     /**
      * Gson object used to encode and decode messages.
      */
+    @Getter(AccessLevel.PROTECTED)
     private static final Gson GSON =
                     new GsonBuilder().registerTypeAdapter(StandardCoderObject.class, new StandardTypeAdapter())
                                     .registerTypeAdapterFactory(new MapDoubleAdapterFactory()).create();
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java
index 357b106e..36f15b96 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java
@@ -20,245 +20,40 @@
 
 package org.onap.policy.common.utils.coder;
 
-import com.google.gson.JsonArray;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonNull;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonPrimitive;
-import java.io.IOException;
 import java.io.Reader;
-import java.io.StringReader;
-import java.io.StringWriter;
 import java.io.Writer;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map.Entry;
-import org.yaml.snakeyaml.DumperOptions;
-import org.yaml.snakeyaml.Yaml;
-import org.yaml.snakeyaml.emitter.Emitter;
-import org.yaml.snakeyaml.error.YAMLException;
-import org.yaml.snakeyaml.nodes.MappingNode;
-import org.yaml.snakeyaml.nodes.Node;
-import org.yaml.snakeyaml.nodes.NodeTuple;
-import org.yaml.snakeyaml.nodes.ScalarNode;
-import org.yaml.snakeyaml.nodes.SequenceNode;
-import org.yaml.snakeyaml.nodes.Tag;
-import org.yaml.snakeyaml.resolver.Resolver;
-import org.yaml.snakeyaml.serializer.Serializer;
 
 /**
  * YAML encoder and decoder using the "standard" mechanism, which is currently gson. All
  * of the methods perform conversion to/from YAML (instead of JSON).
  */
 public class StandardYamlCoder extends StandardCoder {
+    private final YamlJsonTranslator translator;
 
     /**
      * Constructs the object.
      */
     public StandardYamlCoder() {
-        super();
+        translator = new YamlJsonTranslator(getGSON());
     }
 
     @Override
     protected String toJson(Object object) {
-        StringWriter output = new StringWriter();
-        toJson(output, object);
-        return output.toString();
+        return translator.toYaml(object);
     }
 
     @Override
     protected void toJson(Writer target, Object object) {
-        DumperOptions dumper = new DumperOptions();
-        Serializer serializer = new Serializer(new Emitter(target, dumper), new Resolver(), dumper, null);
-
-        try {
-            serializer.open();
-            serializer.serialize(makeYaml(toJsonTree(object)));
-            serializer.close();
-
-        } catch (IOException e) {
-            throw new YAMLException(e);
-        }
+        translator.toYaml(target, object);
     }
 
     @Override
     protected <T> T fromJson(String yaml, Class<T> clazz) {
-        Node node = new Yaml().compose(new StringReader(yaml));
-        return fromJson(makeGson(node), clazz);
+        return translator.fromYaml(yaml, clazz);
     }
 
     @Override
     protected <T> T fromJson(Reader source, Class<T> clazz) {
-        Node node = new Yaml().compose(source);
-        return fromJson(makeGson(node), clazz);
-    }
-
-    /**
-     * Converts an arbitrary gson element into a corresponding Yaml node.
-     *
-     * @param jel gson element to be converted
-     * @return a yaml node corresponding to the element
-     */
-    private Node makeYaml(JsonElement jel) {
-        if (jel.isJsonArray()) {
-            return makeYamlSequence((JsonArray) jel);
-
-        } else if (jel.isJsonObject()) {
-            return makeYamlMap((JsonObject) jel);
-
-        } else if (jel.isJsonPrimitive()) {
-            return makeYamlPrim((JsonPrimitive) jel);
-
-        } else {
-            return new ScalarNode(Tag.NULL, "", null, null, DumperOptions.ScalarStyle.PLAIN);
-        }
-    }
-
-    /**
-     * Converts an arbitrary gson array into a corresponding Yaml sequence.
-     *
-     * @param jel gson element to be converted
-     * @return a yaml node corresponding to the element
-     */
-    private Node makeYamlSequence(JsonArray jel) {
-        List<Node> nodes = new ArrayList<>(jel.size());
-        jel.forEach(item -> nodes.add(makeYaml(item)));
-
-        return new SequenceNode(Tag.SEQ, true, nodes, null, null, DumperOptions.FlowStyle.AUTO);
-    }
-
-    /**
-     * Converts an arbitrary gson object into a corresponding Yaml map.
-     *
-     * @param jel gson element to be converted
-     * @return a yaml node corresponding to the element
-     */
-    private Node makeYamlMap(JsonObject jel) {
-        List<NodeTuple> nodes = new ArrayList<>(jel.size());
-
-        for (Entry<String, JsonElement> entry : jel.entrySet()) {
-            Node key = new ScalarNode(Tag.STR, entry.getKey(), null, null, DumperOptions.ScalarStyle.PLAIN);
-            Node value = makeYaml(entry.getValue());
-
-            nodes.add(new NodeTuple(key, value));
-        }
-
-        return new MappingNode(Tag.MAP, true, nodes, null, null, DumperOptions.FlowStyle.AUTO);
-    }
-
-    /**
-     * Converts an arbitrary gson primitive into a corresponding Yaml scalar.
-     *
-     * @param jel gson element to be converted
-     * @return a yaml node corresponding to the element
-     */
-    private Node makeYamlPrim(JsonPrimitive jel) {
-        Tag tag;
-        if (jel.isNumber()) {
-            Class<? extends Number> clazz = jel.getAsNumber().getClass();
-
-            if (clazz == Double.class || clazz == Float.class) {
-                tag = Tag.FLOAT;
-
-            } else {
-                tag = Tag.INT;
-            }
-
-        } else if (jel.isBoolean()) {
-            tag = Tag.BOOL;
-
-        } else {
-            // treat anything else as a string
-            tag = Tag.STR;
-        }
-
-        return new ScalarNode(tag, jel.getAsString(), null, null, DumperOptions.ScalarStyle.PLAIN);
-    }
-
-    /**
-     * Converts an arbitrary Yaml node into a corresponding gson element.
-     *
-     * @param node node to be converted
-     * @return a gson element corresponding to the node
-     */
-    private JsonElement makeGson(Node node) {
-        if (node instanceof MappingNode) {
-            return makeGsonObject((MappingNode) node);
-
-        } else if (node instanceof SequenceNode) {
-            return makeGsonArray((SequenceNode) node);
-
-        } else {
-            return makeGsonPrim((ScalarNode) node);
-        }
-
-        // yaml doesn't appear to use anchor nodes when decoding so ignore them for now
-    }
-
-    /**
-     * Converts a Yaml sequence into a corresponding gson array.
-     *
-     * @param node node to be converted
-     * @return a gson element corresponding to the node
-     */
-    private JsonElement makeGsonArray(SequenceNode node) {
-        List<Node> nodes = node.getValue();
-
-        JsonArray array = new JsonArray(nodes.size());
-        nodes.forEach(subnode -> array.add(makeGson(subnode)));
-
-        return array;
-    }
-
-    /**
-     * Converts a Yaml map into a corresponding gson object.
-     *
-     * @param node node to be converted
-     * @return a gson element corresponding to the node
-     */
-    private JsonElement makeGsonObject(MappingNode node) {
-        JsonObject obj = new JsonObject();
-
-        for (NodeTuple tuple : node.getValue()) {
-            Node key = tuple.getKeyNode();
-            String skey = ((ScalarNode) key).getValue();
-
-            obj.add(skey, makeGson(tuple.getValueNode()));
-        }
-
-        return obj;
-    }
-
-    /**
-     * Converts a Yaml scalar into a corresponding gson primitive.
-     *
-     * @param node node to be converted
-     * @return a gson element corresponding to the node
-     */
-    private JsonElement makeGsonPrim(ScalarNode node) {
-        try {
-            Tag tag = node.getTag();
-
-            if (tag == Tag.INT) {
-                return new JsonPrimitive(Long.valueOf(node.getValue()));
-
-            } else if (tag == Tag.FLOAT) {
-                return new JsonPrimitive(Double.valueOf(node.getValue()));
-
-            } else if (tag == Tag.BOOL) {
-                return new JsonPrimitive(Boolean.valueOf(node.getValue()));
-
-            } else if (tag == Tag.NULL) {
-                return JsonNull.INSTANCE;
-
-            } else {
-                // treat anything else as a string
-                return new JsonPrimitive(node.getValue());
-            }
-
-        } catch (NumberFormatException ex) {
-            // just treat it as a string
-            return new JsonPrimitive(node.getValue());
-        }
+        return translator.fromYaml(source, clazz);
     }
 }
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/YamlJsonTranslator.java b/utils/src/main/java/org/onap/policy/common/utils/coder/YamlJsonTranslator.java
new file mode 100644
index 00000000..906c9fdd
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/YamlJsonTranslator.java
@@ -0,0 +1,321 @@
+/*-
+ * ============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 com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonNull;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map.Entry;
+import org.yaml.snakeyaml.DumperOptions;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.emitter.Emitter;
+import org.yaml.snakeyaml.error.YAMLException;
+import org.yaml.snakeyaml.nodes.MappingNode;
+import org.yaml.snakeyaml.nodes.Node;
+import org.yaml.snakeyaml.nodes.NodeTuple;
+import org.yaml.snakeyaml.nodes.ScalarNode;
+import org.yaml.snakeyaml.nodes.SequenceNode;
+import org.yaml.snakeyaml.nodes.Tag;
+import org.yaml.snakeyaml.resolver.Resolver;
+import org.yaml.snakeyaml.serializer.Serializer;
+
+/**
+ * YAML-JSON translator. The methods may throw either of the runtime exceptions,
+ * YAMLException or JsonSyntaxException.
+ */
+public class YamlJsonTranslator {
+
+    /**
+     * Object to be used to translate between YAML and JsonElement.
+     */
+    private final Gson gson;
+
+    /**
+     * Constructs the object.
+     */
+    public YamlJsonTranslator() {
+        this(new Gson());
+    }
+
+    /**
+     * Constructs the object.
+     *
+     * @param gson the Gson object to be used to serialize and de-serialize
+     */
+    public YamlJsonTranslator(Gson gson) {
+        this.gson = gson;
+    }
+
+    /**
+     * Translates a POJO into a YAML String.
+     *
+     * @param object POJO to be translated
+     * @return YAML representing the original object
+     */
+    public String toYaml(Object object) {
+        StringWriter output = new StringWriter();
+        toYaml(output, object);
+        return output.toString();
+    }
+
+    /**
+     * Serializes a POJO to a writer, as YAML.
+     *
+     * @param target target writer
+     * @param object POJO to be translated
+     */
+    public void toYaml(Writer target, Object object) {
+        DumperOptions dumper = new DumperOptions();
+        Serializer serializer = new Serializer(new Emitter(target, dumper), new Resolver(), dumper, null);
+
+        try {
+            serializer.open();
+            serializer.serialize(makeYaml(toJsonTree(object)));
+            serializer.close();
+
+        } catch (IOException e) {
+            throw new YAMLException(e);
+        }
+    }
+
+    /**
+     * Translates a POJO into a JsonElement.
+     *
+     * @param object POJO to be translated
+     * @return a JsonElement representing the original object
+     */
+    protected JsonElement toJsonTree(Object object) {
+        return gson.toJsonTree(object);
+    }
+
+    /**
+     * Translates a YAML string to a POJO.
+     *
+     * @param yaml YAML string to be translated
+     * @param clazz class of POJO to be created
+     * @return a POJO representing the original YAML
+     */
+    public <T> T fromYaml(String yaml, Class<T> clazz) {
+        return fromYaml(new StringReader(yaml), clazz);
+    }
+
+    /**
+     * Translates a YAML string, read from a reader, into a POJO.
+     *
+     * @param source source of the YAML string to be translated
+     * @param clazz class of POJO to be created
+     * @return a POJO representing the YAML read from the reader
+     */
+    public <T> T fromYaml(Reader source, Class<T> clazz) {
+        Node node = new Yaml().compose(source);
+        return fromJson(makeJson(node), clazz);
+    }
+
+    /**
+     * Translates a JsonElement to a POJO of the given class.
+     *
+     * @param jel element to be translated
+     * @param clazz class of POJO to be created
+     * @return a POJO representing the original element
+     */
+    protected <T> T fromJson(JsonElement jel, Class<T> clazz) {
+        return gson.fromJson(jel, clazz);
+    }
+
+    /**
+     * Converts an arbitrary gson element into a corresponding Yaml node.
+     *
+     * @param jel gson element to be converted
+     * @return a yaml node corresponding to the element
+     */
+    protected Node makeYaml(JsonElement jel) {
+        if (jel.isJsonArray()) {
+            return makeYamlSequence((JsonArray) jel);
+
+        } else if (jel.isJsonObject()) {
+            return makeYamlMap((JsonObject) jel);
+
+        } else if (jel.isJsonPrimitive()) {
+            return makeYamlPrim((JsonPrimitive) jel);
+
+        } else {
+            return new ScalarNode(Tag.NULL, "", null, null, DumperOptions.ScalarStyle.PLAIN);
+        }
+    }
+
+    /**
+     * Converts an arbitrary gson array into a corresponding Yaml sequence.
+     *
+     * @param jel gson element to be converted
+     * @return a yaml node corresponding to the element
+     */
+    protected SequenceNode makeYamlSequence(JsonArray jel) {
+        List<Node> nodes = new ArrayList<>(jel.size());
+        jel.forEach(item -> nodes.add(makeYaml(item)));
+
+        return new SequenceNode(Tag.SEQ, true, nodes, null, null, DumperOptions.FlowStyle.AUTO);
+    }
+
+    /**
+     * Converts an arbitrary gson object into a corresponding Yaml map.
+     *
+     * @param jel gson element to be converted
+     * @return a yaml node corresponding to the element
+     */
+    protected MappingNode makeYamlMap(JsonObject jel) {
+        List<NodeTuple> nodes = new ArrayList<>(jel.size());
+
+        for (Entry<String, JsonElement> entry : jel.entrySet()) {
+            Node key = new ScalarNode(Tag.STR, entry.getKey(), null, null, DumperOptions.ScalarStyle.PLAIN);
+            Node value = makeYaml(entry.getValue());
+
+            nodes.add(new NodeTuple(key, value));
+        }
+
+        return new MappingNode(Tag.MAP, true, nodes, null, null, DumperOptions.FlowStyle.AUTO);
+    }
+
+    /**
+     * Converts an arbitrary gson primitive into a corresponding Yaml scalar.
+     *
+     * @param jel gson element to be converted
+     * @return a yaml node corresponding to the element
+     */
+    protected ScalarNode makeYamlPrim(JsonPrimitive jel) {
+        Tag tag;
+        if (jel.isNumber()) {
+            Class<? extends Number> clazz = jel.getAsNumber().getClass();
+
+            if (clazz == Double.class || clazz == Float.class) {
+                tag = Tag.FLOAT;
+
+            } else {
+                tag = Tag.INT;
+            }
+
+        } else if (jel.isBoolean()) {
+            tag = Tag.BOOL;
+
+        } else {
+            // treat anything else as a string
+            tag = Tag.STR;
+        }
+
+        return new ScalarNode(tag, jel.getAsString(), null, null, DumperOptions.ScalarStyle.PLAIN);
+    }
+
+    /**
+     * Converts an arbitrary Yaml node into a corresponding gson element.
+     *
+     * @param node node to be converted
+     * @return a gson element corresponding to the node
+     */
+    protected JsonElement makeJson(Node node) {
+        if (node instanceof MappingNode) {
+            return makeJsonObject((MappingNode) node);
+
+        } else if (node instanceof SequenceNode) {
+            return makeJsonArray((SequenceNode) node);
+
+        } else {
+            return makeJsonPrim((ScalarNode) node);
+        }
+
+        // yaml doesn't appear to use anchor nodes when decoding so ignore them for now
+    }
+
+    /**
+     * Converts a Yaml sequence into a corresponding gson array.
+     *
+     * @param node node to be converted
+     * @return a gson element corresponding to the node
+     */
+    protected JsonArray makeJsonArray(SequenceNode node) {
+        List<Node> nodes = node.getValue();
+
+        JsonArray array = new JsonArray(nodes.size());
+        nodes.forEach(subnode -> array.add(makeJson(subnode)));
+
+        return array;
+    }
+
+    /**
+     * Converts a Yaml map into a corresponding gson object.
+     *
+     * @param node node to be converted
+     * @return a gson element corresponding to the node
+     */
+    protected JsonObject makeJsonObject(MappingNode node) {
+        JsonObject obj = new JsonObject();
+
+        for (NodeTuple tuple : node.getValue()) {
+            Node key = tuple.getKeyNode();
+            String skey = ((ScalarNode) key).getValue();
+
+            obj.add(skey, makeJson(tuple.getValueNode()));
+        }
+
+        return obj;
+    }
+
+    /**
+     * Converts a Yaml scalar into a corresponding gson primitive.
+     *
+     * @param node node to be converted
+     * @return a gson element corresponding to the node
+     */
+    protected JsonElement makeJsonPrim(ScalarNode node) {
+        try {
+            Tag tag = node.getTag();
+
+            if (tag == Tag.INT) {
+                return new JsonPrimitive(Long.valueOf(node.getValue()));
+
+            } else if (tag == Tag.FLOAT) {
+                return new JsonPrimitive(Double.valueOf(node.getValue()));
+
+            } else if (tag == Tag.BOOL) {
+                return new JsonPrimitive(Boolean.valueOf(node.getValue()));
+
+            } else if (tag == Tag.NULL) {
+                return JsonNull.INSTANCE;
+
+            } else {
+                // treat anything else as a string
+                return new JsonPrimitive(node.getValue());
+            }
+
+        } catch (NumberFormatException ex) {
+            // just treat it as a string
+            return new JsonPrimitive(node.getValue());
+        }
+    }
+}
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
index 2992933f..2a70f85a 100644
--- 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
@@ -44,6 +44,7 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import org.junit.Before;
@@ -201,6 +202,22 @@ public class StandardCoderTest {
     }
 
     @Test
+    public void testToJsonTree_testFromJsonJsonElementClassT() throws Exception {
+        MyMap map = new MyMap();
+        map.props = new LinkedHashMap<>();
+        map.props.put("jel keyA", "jel valueA");
+        map.props.put("jel keyB", "jel valueB");
+
+        JsonElement json = coder.toJsonTree(map);
+        assertEquals("{'props':{'jel keyA':'jel valueA','jel keyB':'jel valueB'}}".replace('\'', '"'), json.toString());
+
+        Object result = coder.fromJson(json, MyMap.class);
+
+        assertNotNull(result);
+        assertEquals("{jel keyA=jel valueA, jel keyB=jel valueB}", result.toString());
+    }
+
+    @Test
     public void testConvertFromDouble() throws Exception {
         String text = "[listA, {keyA=100}, 200]";
         assertEquals(text, coder.decode(text, Object.class).toString());
@@ -276,7 +293,12 @@ public class StandardCoderTest {
         }
     }
 
-    private static class MyMap {
+    public static class MyMap {
         private Map<String, Object> props;
+
+        @Override
+        public String toString() {
+            return props.toString();
+        }
     }
 }
diff --git a/utils/src/test/java/org/onap/policy/common/utils/coder/StandardYamlCoderTest.java b/utils/src/test/java/org/onap/policy/common/utils/coder/StandardYamlCoderTest.java
index 6ec20663..e38c5c9c 100644
--- a/utils/src/test/java/org/onap/policy/common/utils/coder/StandardYamlCoderTest.java
+++ b/utils/src/test/java/org/onap/policy/common/utils/coder/StandardYamlCoderTest.java
@@ -20,26 +20,20 @@
 
 package org.onap.policy.common.utils.coder;
 
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
 
 import java.io.File;
-import java.io.IOException;
-import java.io.Writer;
+import java.io.StringWriter;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
-import java.util.List;
-import java.util.Map;
-import lombok.EqualsAndHashCode;
 import org.junit.Before;
 import org.junit.Test;
+import org.onap.policy.common.utils.coder.YamlJsonTranslatorTest.Container;
 
 public class StandardYamlCoderTest {
     private static final File YAML_FILE =
-                    new File("src/test/resources/org/onap/policy/common/utils/coder/StandardYamlCoder.yaml");
+                    new File("src/test/resources/org/onap/policy/common/utils/coder/YamlJsonTranslator.yaml");
 
     private StandardYamlCoder coder;
     private Container cont;
@@ -59,30 +53,13 @@ public class StandardYamlCoderTest {
     }
 
     @Test
-    public void testToJsonWriterObject() throws Exception {
-        IOException ex = new IOException("expected exception");
+    public void testToJsonWriterObject() throws CoderException {
+        StringWriter wtr = new StringWriter();
+        coder.encode(wtr, cont);
+        String yaml = wtr.toString();
 
-        // writer that throws an exception when the write() method is invoked
-        Writer wtr = new Writer() {
-            @Override
-            public void write(char[] cbuf, int off, int len) throws IOException {
-                throw ex;
-            }
-
-            @Override
-            public void flush() throws IOException {
-                // do nothing
-            }
-
-            @Override
-            public void close() throws IOException {
-                // do nothing
-            }
-        };
-
-        assertThatThrownBy(() -> coder.encode(wtr, cont)).isInstanceOf(CoderException.class);
-
-        wtr.close();
+        Container cont2 = coder.decode(yaml, Container.class);
+        assertEquals(cont, cont2);
     }
 
     @Test
@@ -94,58 +71,15 @@ public class StandardYamlCoderTest {
 
     @Test
     public void testFromJsonReaderClassOfT() {
-        assertNotNull(cont.item);
-        assertTrue(cont.item.boolVal);
-        assertEquals(1000L, cont.item.longVal);
-        assertEquals(1010.1f, cont.item.floatVal, 0.00001);
-
-        assertEquals(4, cont.list.size());
-        assertNull(cont.list.get(1));
-
-        assertEquals(20, cont.list.get(0).intVal);
-        assertEquals("string 30", cont.list.get(0).stringVal);
-        assertNull(cont.list.get(0).nullVal);
-
-        assertEquals(40.0, cont.list.get(2).doubleVal, 0.000001);
-        assertNull(cont.list.get(2).nullVal);
-        assertNotNull(cont.list.get(2).another);
-        assertEquals(50, cont.list.get(2).another.intVal);
-
-        assertTrue(cont.list.get(3).boolVal);
-
-        assertNotNull(cont.map);
-        assertEquals(3, cont.map.size());
-
-        assertNotNull(cont.map.get("itemA"));
-        assertEquals("stringA", cont.map.get("itemA").stringVal);
-
-        assertNotNull(cont.map.get("itemB"));
-        assertEquals("stringB", cont.map.get("itemB").stringVal);
-
-        double dbl = 123456789012345678901234567890.0;
-        assertEquals(dbl, cont.map.get("itemB").doubleVal, 1000.0);
-
-        assertNotNull(cont.map.get("itemC"));
-        assertTrue(cont.map.get("itemC").boolVal);
+        YamlJsonTranslatorTest.verify(cont);
     }
 
-
-    @EqualsAndHashCode
-    public static class Container {
-        private Item item;
-        private List<Item> list;
-        private Map<String, Item> map;
-    }
-
-    @EqualsAndHashCode
-    public static class Item {
-        private boolean boolVal;
-        private int intVal;
-        private long longVal;
-        private double doubleVal;
-        private float floatVal;
-        private String stringVal;
-        private Object nullVal;
-        private Item another;
+    @Test
+    public void testStandardTypeAdapter() throws Exception {
+        String yaml = "abc: def\n";
+        StandardCoderObject sco = coder.fromJson(yaml, StandardCoderObject.class);
+        assertNotNull(sco.getData());
+        assertEquals("{'abc':'def'}".replace('\'', '"'), sco.getData().toString());
+        assertEquals(yaml, coder.toJson(sco));
     }
 }
diff --git a/utils/src/test/java/org/onap/policy/common/utils/coder/YamlJsonTranslatorTest.java b/utils/src/test/java/org/onap/policy/common/utils/coder/YamlJsonTranslatorTest.java
new file mode 100644
index 00000000..c76b775a
--- /dev/null
+++ b/utils/src/test/java/org/onap/policy/common/utils/coder/YamlJsonTranslatorTest.java
@@ -0,0 +1,170 @@
+/*-
+ * ============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.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.List;
+import java.util.Map;
+import lombok.EqualsAndHashCode;
+import org.junit.Before;
+import org.junit.Test;
+import org.yaml.snakeyaml.error.YAMLException;
+
+public class YamlJsonTranslatorTest {
+    private static final File YAML_FILE =
+                    new File("src/test/resources/org/onap/policy/common/utils/coder/YamlJsonTranslator.yaml");
+
+    private Container cont;
+    private YamlJsonTranslator translator;
+
+    /**
+     * Creates {@link #translator} and uses it to load {@link #cont}.
+     *
+     * @throws IOException if an error occurs
+     */
+    @Before
+    public void setUp() throws IOException {
+        translator = new YamlJsonTranslator();
+
+        try (FileReader rdr = new FileReader(YAML_FILE)) {
+            cont = translator.fromYaml(rdr, Container.class);
+        }
+    }
+
+    @Test
+    public void testToYamlObject() {
+        String yaml = translator.toYaml(cont);
+
+        Container cont2 = translator.fromYaml(yaml, Container.class);
+        assertEquals(cont, cont2);
+    }
+
+    @Test
+    public void testToYamlWriterObject() throws IOException {
+        IOException ex = new IOException("expected exception");
+
+        // writer that throws an exception when the write() method is invoked
+        Writer wtr = new Writer() {
+            @Override
+            public void write(char[] cbuf, int off, int len) throws IOException {
+                throw ex;
+            }
+
+            @Override
+            public void flush() throws IOException {
+                // do nothing
+            }
+
+            @Override
+            public void close() throws IOException {
+                // do nothing
+            }
+        };
+
+        assertThatThrownBy(() -> translator.toYaml(wtr, cont)).isInstanceOf(YAMLException.class);
+
+        wtr.close();
+    }
+
+    @Test
+    public void testFromYamlStringClassOfT() throws IOException {
+        String yaml = new String(Files.readAllBytes(YAML_FILE.toPath()), StandardCharsets.UTF_8);
+        Container cont2 = translator.fromYaml(yaml, Container.class);
+        assertEquals(cont, cont2);
+    }
+
+    @Test
+    public void testFromYamlReaderClassOfT() {
+        verify(cont);
+    }
+
+    /**
+     * Verifies that the container has contents matching the yaml file.
+     *
+     * @param container container whose contents are to be verified
+     */
+    public static void verify(Container container) {
+        assertNotNull(container.item);
+        assertTrue(container.item.boolVal);
+        assertEquals(1000L, container.item.longVal);
+        assertEquals(1010.1f, container.item.floatVal, 0.00001);
+
+        assertEquals(4, container.list.size());
+        assertNull(container.list.get(1));
+
+        assertEquals(20, container.list.get(0).intVal);
+        assertEquals("string 30", container.list.get(0).stringVal);
+        assertNull(container.list.get(0).nullVal);
+
+        assertEquals(40.0, container.list.get(2).doubleVal, 0.000001);
+        assertNull(container.list.get(2).nullVal);
+        assertNotNull(container.list.get(2).another);
+        assertEquals(50, container.list.get(2).another.intVal);
+
+        assertTrue(container.list.get(3).boolVal);
+
+        assertNotNull(container.map);
+        assertEquals(3, container.map.size());
+
+        assertNotNull(container.map.get("itemA"));
+        assertEquals("stringA", container.map.get("itemA").stringVal);
+
+        assertNotNull(container.map.get("itemB"));
+        assertEquals("stringB", container.map.get("itemB").stringVal);
+
+        double dbl = 123456789012345678901234567890.0;
+        assertEquals(dbl, container.map.get("itemB").doubleVal, 1000.0);
+
+        assertNotNull(container.map.get("itemC"));
+        assertTrue(container.map.get("itemC").boolVal);
+    }
+
+
+    @EqualsAndHashCode
+    public static class Container {
+        protected Item item;
+        protected List<Item> list;
+        protected Map<String, Item> map;
+    }
+
+    @EqualsAndHashCode
+    public static class Item {
+        protected boolean boolVal;
+        protected int intVal;
+        protected long longVal;
+        protected double doubleVal;
+        protected float floatVal;
+        protected String stringVal;
+        protected Object nullVal;
+        protected Item another;
+    }
+}
diff --git a/utils/src/test/resources/org/onap/policy/common/utils/coder/StandardYamlCoder.yaml b/utils/src/test/resources/org/onap/policy/common/utils/coder/YamlJsonTranslator.yaml
index 1da7bfa3..1da7bfa3 100644
--- a/utils/src/test/resources/org/onap/policy/common/utils/coder/StandardYamlCoder.yaml
+++ b/utils/src/test/resources/org/onap/policy/common/utils/coder/YamlJsonTranslator.yaml