org.mitre.provenance.plusobject.json.JsonObjectPropertyWrapper.java Source code

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Here is the source code for org.mitre.provenance.plusobject.json.JsonObjectPropertyWrapper.java

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/* Copyright 2014 MITRE Corporation
 *
 * 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 org.mitre.provenance.plusobject.json;

import java.util.HashSet;
import java.util.Map.Entry;

import org.mitre.provenance.PropertySet;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;

/**
 * This is a wrapper class that allows a JsonObject from google GSON to behave like a PropertyContainer.
 * This makes it a lot easier to get/set properties out of a simple container into provenance objects.
 * @author moxious
 */
public class JsonObjectPropertyWrapper implements PropertySet {
    JsonObject obj = null;

    /** Create a new wrapper object that is entirely informed by its contained JsonObject */
    public JsonObjectPropertyWrapper(JsonObject o) {
        obj = o;
    }

    public boolean hasProperty(String key) {
        return obj.has(key);
    }

    public Object getProperty(String key) {
        if (!obj.has(key))
            return null;
        //JsonPrimitive p = obj.get(key).getAsJsonPrimitive();
        JsonElement elem = obj.get(key);

        if (elem.isJsonPrimitive() && ((JsonPrimitive) elem).isString())
            return elem.getAsString();
        if (elem.isJsonPrimitive() && ((JsonPrimitive) elem).isNumber())
            return elem.getAsLong();

        if (elem.isJsonArray()) {
            JsonArray arr = (JsonArray) elem;

            String[] r = new String[arr.size()];

            for (int x = 0; x < arr.size(); x++) {
                r[x] = arr.get(x).getAsString();
            }

            return r;
        }

        // Default case.
        return elem.getAsString();
    }

    public Object getProperty(String key, Object defaultValue) {
        if (!hasProperty(key))
            return defaultValue;
        return getProperty(key);
    }

    public Iterable<String> getPropertyKeys() {
        HashSet<String> keys = new HashSet<String>();
        for (Entry<String, JsonElement> e : obj.entrySet())
            keys.add(e.getKey());

        return keys;
    }
}