Merge "Add StandardCoderObject to hide GSON internals"
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
index 66a308f..bb51f2b 100644
--- 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
@@ -106,4 +106,22 @@
* @throws CoderException if an error occurs
*/
<T> T decode(File source, Class<T> clazz) throws CoderException;
+
+ /**
+ * Converts an object/POJO to a standard object.
+ *
+ * @param object object to be converted
+ * @return a new standard object representing the original object
+ * @throws CoderException if an error occurs
+ */
+ StandardCoderObject toStandard(Object object) throws CoderException;
+
+ /**
+ * Converts a standard object to an object/POJO.
+ *
+ * @param sco the standard object to be converted
+ * @return a new object represented by the standard object
+ * @throws CoderException if an error occurs
+ */
+ <T> T fromStandard(StandardCoderObject sco, Class<T> clazz) throws CoderException;
}
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 389720f..69a211b 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
@@ -21,6 +21,11 @@
package org.onap.policy.common.utils.coder;
import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonElement;
+import com.google.gson.TypeAdapter;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
@@ -42,7 +47,8 @@
/**
* Gson object used to encode and decode messages.
*/
- private static final Gson GSON = new Gson();
+ private static final Gson GSON = new GsonBuilder()
+ .registerTypeAdapter(StandardCoderObject.class, new StandardTypeAdapter()).create();
/**
* Constructs the object.
@@ -137,6 +143,26 @@
}
}
+ @Override
+ public StandardCoderObject toStandard(Object object) throws CoderException {
+ try {
+ return new StandardCoderObject(GSON.toJsonTree(object));
+
+ } catch (RuntimeException e) {
+ throw new CoderException(e);
+ }
+ }
+
+ @Override
+ public <T> T fromStandard(StandardCoderObject sco, Class<T> clazz) throws CoderException {
+ try {
+ return GSON.fromJson(sco.getData(), clazz);
+
+ } catch (RuntimeException e) {
+ throw new CoderException(e);
+ }
+ }
+
// the remaining methods are wrappers that can be overridden by junit tests
/**
@@ -223,4 +249,32 @@
protected <T> T fromJson(Reader source, Class<T> clazz) {
return GSON.fromJson(source, clazz);
}
+
+ /**
+ * Adapter for standard objects.
+ */
+ private static class StandardTypeAdapter extends TypeAdapter<StandardCoderObject> {
+
+ /**
+ * Used to read/write a JsonElement.
+ */
+ private static TypeAdapter<JsonElement> elementAdapter = new Gson().getAdapter(JsonElement.class);
+
+ /**
+ * Constructs the object.
+ */
+ public StandardTypeAdapter() {
+ super();
+ }
+
+ @Override
+ public void write(JsonWriter out, StandardCoderObject value) throws IOException {
+ elementAdapter.write(out, value.getData());
+ }
+
+ @Override
+ public StandardCoderObject read(JsonReader in) throws IOException {
+ return new StandardCoderObject(elementAdapter.read(in));
+ }
+ }
}
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoderObject.java b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoderObject.java
new file mode 100644
index 0000000..60c5f4e
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoderObject.java
@@ -0,0 +1,93 @@
+/*
+ * ============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.JsonElement;
+
+/**
+ * Object type used by the {@link StandardCoder}. Different serialization tools have
+ * different "standard objects". For instance, GSON uses {@link JsonElement}. This class
+ * wraps that object so that it can be used without exposing the object, itself.
+ */
+public class StandardCoderObject {
+
+ /**
+ * Data wrapped by this.
+ */
+ private final JsonElement data;
+
+ /**
+ * Constructs the object.
+ */
+ public StandardCoderObject() {
+ data = null;
+ }
+
+ /**
+ * Constructs the object.
+ *
+ * @param data data wrapped by this object.
+ */
+ protected StandardCoderObject(JsonElement data) {
+ this.data = data;
+ }
+
+ /**
+ * Gets the data wrapped by this.
+ *
+ * @return the data wrapped by this
+ */
+ protected JsonElement getData() {
+ return data;
+ }
+
+ /**
+ * Gets a field's value from this object, traversing the object hierarchy.
+ *
+ * @param fields field hierarchy
+ * @return the field value or {@code null} if the field does not exist or is not a
+ * primitive
+ */
+ public String getString(String... fields) {
+
+ /*
+ * This could be relatively easily modified to allow Integer arguments, as well,
+ * which would be used to specify indices within an array.
+ */
+
+ JsonElement jel = data;
+
+ for (String field : fields) {
+ if (jel == null) {
+ return null;
+ }
+
+ if (jel.isJsonObject()) {
+ jel = jel.getAsJsonObject().get(field);
+
+ } else {
+ return null;
+ }
+ }
+
+ return (jel != null && jel.isJsonPrimitive() ? jel.getAsString() : null);
+ }
+}
diff --git a/utils/src/test/java/org/onap/policy/common/utils/coder/StandardCoderObjectTest.java b/utils/src/test/java/org/onap/policy/common/utils/coder/StandardCoderObjectTest.java
new file mode 100644
index 0000000..44086f3
--- /dev/null
+++ b/utils/src/test/java/org/onap/policy/common/utils/coder/StandardCoderObjectTest.java
@@ -0,0 +1,89 @@
+/*
+ * ============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.assertNull;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import org.junit.Before;
+import org.junit.Test;
+
+public class StandardCoderObjectTest {
+ private static final Gson gson = new Gson();
+
+ private static final String PROP1 = "abc";
+ private static final String PROP2 = "ghi";
+ private static final String PROP2b = "jkl";
+ private static final String VAL1 = "def";
+ private static final String VAL2 = "mno";
+ private static final String JSON = "{'abc':'def','ghi':{'jkl':'mno'}}".replace('\'', '"');
+
+ private StandardCoderObject sco;
+
+ /**
+ * Creates a standard object, populated with some data.
+ *
+ * @throws Exception if an error occurs
+ */
+ @Before
+ public void setUp() throws Exception {
+ sco = new StandardCoderObject(gson.fromJson(JSON, JsonElement.class));
+ }
+
+ @Test
+ public void testStandardCoderObject() {
+ assertNull(new StandardCoderObject().getData());
+ }
+
+ @Test
+ public void testStandardCoderObjectJsonElement() {
+ assertNotNull(sco.getData());
+ assertEquals(JSON, gson.toJson(sco.getData()));
+ }
+
+ @Test
+ public void testGetString() throws Exception {
+ // one field
+ assertEquals(VAL1, sco.getString(PROP1));
+
+ // multiple fields
+ assertEquals(VAL2, sco.getString(PROP2, PROP2b));
+
+ // not found
+ assertNull(sco.getString("xyz"));
+
+ // read from null object
+ assertNull(new StandardCoderObject().getString());
+ assertNull(new StandardCoderObject().getString(PROP1));
+
+ JsonElement obj = gson.fromJson("{'abc':[]}".replace('\'', '"'), JsonElement.class);
+ sco = new StandardCoderObject(obj);
+
+ // not a primitive
+ assertNull(sco.getString(PROP1));
+
+ // not a JSON object
+ assertNull(sco.getString(PROP1, PROP2));
+ }
+}
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 25cce74..7583d77 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
@@ -22,6 +22,7 @@
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.when;
@@ -196,4 +197,51 @@
assertThatThrownBy(() -> coder.decode(file, JsonElement.class)).isInstanceOf(CoderException.class)
.hasCause(ioe);
}
+
+ @Test
+ public void testToStandard() throws Exception {
+ MyObject obj = new MyObject();
+ obj.abc = "xyz";
+ StandardCoderObject sco = coder.toStandard(obj);
+ assertNotNull(sco.getData());
+ assertEquals("{'abc':'xyz'}".replace('\'', '"'), sco.getData().toString());
+
+ // class instead of object -> exception
+ assertThatThrownBy(() -> coder.toStandard(String.class)).isInstanceOf(CoderException.class);
+ }
+
+ @Test
+ public void testFromStandard() throws Exception {
+ MyObject obj = new MyObject();
+ obj.abc = "pdq";
+ StandardCoderObject sco = coder.toStandard(obj);
+
+ MyObject obj2 = coder.fromStandard(sco, MyObject.class);
+ assertEquals(obj.toString(), obj2.toString());
+
+ // null class -> exception
+ assertThatThrownBy(() -> coder.fromStandard(sco, null)).isInstanceOf(CoderException.class);
+ }
+
+ @Test
+ public void testStandardTypeAdapter() throws Exception {
+ String json = "{'abc':'def'}".replace('\'', '"');
+ StandardCoderObject sco = coder.fromJson(json, StandardCoderObject.class);
+ assertNotNull(sco.getData());
+ assertEquals(json, sco.getData().toString());
+ assertEquals(json, coder.toJson(sco));
+
+ // invalid json -> exception
+ assertThatThrownBy(() -> coder.fromJson(new StringReader("["), StandardCoderObject.class));
+ }
+
+
+ private static class MyObject {
+ private String abc;
+
+ @Override
+ public String toString() {
+ return "MyObject [abc=" + abc + "]";
+ }
+ }
}