feature: add OptimizelyJSON (#371)

Author: jaeopt

core-api/src/main/java/com/optimizely/ab/config/parser/ConfigParser.java

@@ -38,4 +38,10 @@ public interface ConfigParser {
      * @throws ConfigParseException when there's an issue parsing the provided project config
      */
     ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParseException;
+
+    /**
+     * OptimizelyJSON parsing
+     */
+    String toJson(Object src) throws JsonParseException;
+    <T> T fromJson(String json, Class<T> clazz) throws JsonParseException;
 }

core-api/src/main/java/com/optimizely/ab/config/parser/GsonConfigParser.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, 2019, Optimizely and contributors
+ *    Copyright 2016-2017, 2019-2020, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -27,7 +27,23 @@
 /**
  * {@link Gson}-based config parser implementation.
  */
-final class GsonConfigParser implements ConfigParser {
+final public class GsonConfigParser implements ConfigParser {
+    private Gson gson;
+
+    public GsonConfigParser() {
+        this(new GsonBuilder()
+            .registerTypeAdapter(Audience.class, new AudienceGsonDeserializer())
+            .registerTypeAdapter(TypedAudience.class, new AudienceGsonDeserializer())
+            .registerTypeAdapter(Experiment.class, new ExperimentGsonDeserializer())
+            .registerTypeAdapter(FeatureFlag.class, new FeatureFlagGsonDeserializer())
+            .registerTypeAdapter(Group.class, new GroupGsonDeserializer())
+            .registerTypeAdapter(DatafileProjectConfig.class, new DatafileGsonDeserializer())
+            .create());
+    }
+
+    GsonConfigParser(Gson gson) {
+        this.gson = gson;
+    }
 
     @Override
     public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParseException {
@@ -37,19 +53,24 @@ public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParse
         if (json.length() == 0) {
             throw new ConfigParseException("Unable to parse empty json.");
         }
-        Gson gson = new GsonBuilder()
-            .registerTypeAdapter(Audience.class, new AudienceGsonDeserializer())
-            .registerTypeAdapter(TypedAudience.class, new AudienceGsonDeserializer())
-            .registerTypeAdapter(Experiment.class, new ExperimentGsonDeserializer())
-            .registerTypeAdapter(FeatureFlag.class, new FeatureFlagGsonDeserializer())
-            .registerTypeAdapter(Group.class, new GroupGsonDeserializer())
-            .registerTypeAdapter(DatafileProjectConfig.class, new DatafileGsonDeserializer())
-            .create();
 
         try {
             return gson.fromJson(json, DatafileProjectConfig.class);
         } catch (Exception e) {
             throw new ConfigParseException("Unable to parse datafile: " + json, e);
         }
     }
+
+    public String toJson(Object src) {
+        return gson.toJson(src);
+    }
+
+    public <T> T fromJson(String json, Class<T> clazz) throws JsonParseException {
+        try {
+            return gson.fromJson(json, clazz);
+        } catch (Exception e) {
+            throw new JsonParseException("Unable to parse JSON string: " + e.toString());
+        }
+    }
+
 }

core-api/src/main/java/com/optimizely/ab/config/parser/JacksonConfigParser.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2018, Optimizely and contributors
+ *    Copyright 2016-2018, 2020, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
  */
 package com.optimizely.ab.config.parser;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.optimizely.ab.config.DatafileProjectConfig;
@@ -25,11 +26,12 @@
 import com.optimizely.ab.config.audience.TypedAudience;
 
 import javax.annotation.Nonnull;
+import java.io.IOException;
 
 /**
  * {@code Jackson}-based config parser implementation.
  */
-final class JacksonConfigParser implements ConfigParser {
+final public class JacksonConfigParser implements ConfigParser {
     private ObjectMapper objectMapper;
 
     public JacksonConfigParser() {
@@ -61,4 +63,23 @@ public ProjectConfigModule() {
             addDeserializer(Condition.class, new ConditionJacksonDeserializer(objectMapper));
         }
     }
+
+    @Override
+    public String toJson(Object src) throws JsonParseException {
+        try {
+            return objectMapper.writeValueAsString(src);
+        } catch (JsonProcessingException e) {
+            throw new JsonParseException("Serialization failed: " + e.toString());
+        }
+    }
+
+    @Override
+    public <T> T fromJson(String json, Class<T> clazz) throws JsonParseException {
+        try {
+            return objectMapper.readValue(json, clazz);
+        } catch (IOException e) {
+            throw new JsonParseException("Unable to parse JSON string: " + e.toString());
+        }
+    }
+
 }

core-api/src/main/java/com/optimizely/ab/config/parser/JsonConfigParser.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2019, Optimizely and contributors
+ *    Copyright 2016-2019, 2020, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -28,17 +28,12 @@
 import org.json.JSONTokener;
 
 import javax.annotation.Nonnull;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 
 /**
  * {@code org.json}-based config parser implementation.
  */
-final class JsonConfigParser implements ConfigParser {
+final public class JsonConfigParser implements ConfigParser {
 
     @Override
     public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParseException {
@@ -389,4 +384,22 @@ private List<Rollout> parseRollouts(JSONArray rolloutsJson) {
 
         return rollouts;
     }
+
+    @Override
+    public String toJson(Object src) {
+        JSONObject json = (JSONObject)JsonHelpers.convertToJsonObject(src);
+        return json.toString();
+    }
+
+    @Override
+    public <T> T fromJson(String json, Class<T> clazz) throws JsonParseException {
+        if (Map.class.isAssignableFrom(clazz)) {
+            JSONObject obj = new JSONObject(json);
+            return (T)JsonHelpers.jsonObjectToMap(obj);
+        }
+
+        // org.json parser does not support parsing to user objects
+        throw new JsonParseException("Parsing fails with a unsupported type");
+    }
+
 }

core-api/src/main/java/com/optimizely/ab/config/parser/JsonHelpers.java

@@ -0,0 +1,81 @@
+/**
+ *
+ *    Copyright 2020, Optimizely and contributors
+ *
+ *    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.
+ */
+package com.optimizely.ab.config.parser;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+import java.util.*;
+
+final class JsonHelpers {
+
+    static Object convertToJsonObject(Object obj) {
+        if (obj instanceof Map) {
+            Map<Object, Object> map = (Map)obj;
+            JSONObject jObj = new JSONObject();
+            for (Map.Entry entry : map.entrySet()) {
+                jObj.put(entry.getKey().toString(), convertToJsonObject(entry.getValue()));
+            }
+            return jObj;
+        } else if (obj instanceof List) {
+            List list = (List)obj;
+            JSONArray jArray = new JSONArray();
+            for (Object value : list) {
+                jArray.put(convertToJsonObject(value));
+            }
+            return jArray;
+        } else {
+            return obj;
+        }
+    }
+
+    static Map<String, Object> jsonObjectToMap(JSONObject jObj) {
+        Map<String, Object> map = new HashMap<>();
+
+        Iterator<String> keys = jObj.keys();
+        while(keys.hasNext()) {
+            String key = keys.next();
+            Object value = jObj.get(key);
+
+            if (value instanceof JSONArray) {
+                value = jsonArrayToList((JSONArray)value);
+            } else if (value instanceof JSONObject) {
+                value = jsonObjectToMap((JSONObject)value);
+            }
+
+            map.put(key, value);
+        }
+
+        return map;
+    }
+
+    static List<Object> jsonArrayToList(JSONArray array) {
+        List<Object> list = new ArrayList<>();
+        for(Object value : array) {
+            if (value instanceof JSONArray) {
+                value = jsonArrayToList((JSONArray)value);
+            } else if (value instanceof JSONObject) {
+                value = jsonObjectToMap((JSONObject)value);
+            }
+
+            list.add(value);
+        }
+
+        return list;
+    }
+
+}

core-api/src/main/java/com/optimizely/ab/config/parser/JsonParseException.java

@@ -0,0 +1,27 @@
+/**
+ *
+ *    Copyright 2020, Optimizely and contributors
+ *
+ *    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.
+ */
+package com.optimizely.ab.config.parser;
+
+public final class JsonParseException extends Exception {
+    public JsonParseException(String message) {
+        super(message);
+    }
+
+    public JsonParseException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

core-api/src/main/java/com/optimizely/ab/config/parser/JsonSimpleConfigParser.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2019, Optimizely and contributors
+ *    Copyright 2016-2019, 2020, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -26,22 +26,20 @@
 import com.optimizely.ab.internal.ConditionUtils;
 import org.json.simple.JSONArray;
 import org.json.simple.JSONObject;
+import org.json.simple.JSONValue;
+import org.json.simple.parser.ContainerFactory;
 import org.json.simple.parser.JSONParser;
 import org.json.simple.parser.ParseException;
 
 import javax.annotation.Nonnull;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
  * {@code json-simple}-based config parser implementation.
  */
-final class JsonSimpleConfigParser implements ConfigParser {
+final public class JsonSimpleConfigParser implements ConfigParser {
 
     @Override
     public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParseException {
@@ -372,5 +370,35 @@ private List<Rollout> parseRollouts(JSONArray rolloutsJson) {
 
         return rollouts;
     }
+
+    @Override
+    public String toJson(Object src) {
+        return JSONValue.toJSONString(src);
+    }
+
+    @Override
+    public <T> T fromJson(String json, Class<T> clazz) throws JsonParseException {
+        if (Map.class.isAssignableFrom(clazz)) {
+            try {
+                return (T)new JSONParser().parse(json, new ContainerFactory() {
+                    @Override
+                    public Map createObjectContainer() {
+                        return new HashMap();
+                    }
+
+                    @Override
+                    public List creatArrayContainer() {
+                        return new ArrayList();
+                    }
+                });
+            } catch (ParseException e) {
+                throw new JsonParseException("Unable to parse JSON string: " + e.toString());
+            }
+        }
+
+        // org.json.simple does not support parsing to user objects
+        throw new JsonParseException("Parsing fails with a unsupported type");
+    }
+
 }