edu.brandeis.cs.json.JsonProxy.java Source code

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/**********************************************************************************************************************
 Copyright [2014] [Chunqi SHI (chunqi.shi@hotmail.com)]
    
 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 edu.brandeis.cs.json;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;

import java.util.Collection;

/**
 * <p>This define Proxy class of Json object ( e.g. {key_1:value_1, key_2:value_2, ..., key_m:value_m} )
 * and Json Array (e.g. [obj_1, obj_2, ..., obj_n])</p>
 */
public class JsonProxy {

    public static String obj2json(Object obj) throws Exception {
        ObjectWriter ow = new ObjectMapper().writer();
        String json = null;
        try {
            json = ow.writeValueAsString(obj);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
            throw new Exception(e);
        }
        return json;
    }

    /**
     * Json util read string as Json object
     * @param json
     * @return
     */
    public static Object str2json(String json) {
        if (json == null)
            return null;
        json = json.trim();
        if (json.startsWith("{")) {
            return JsonProxy.readObject(json);
        } else if (json.startsWith("[")) {
            return JsonProxy.readArray(json);
        } else {
            return json;
        }
    }

    /**
     *
     */
    public static interface JsonObject {
        /** read string into jsonObject **/
        public JsonObject read(String s);

        /** write jsonObject int string **/
        public String toString();

        /** has / get / put / remove **/
        public boolean has(String key);

        public Object get(String key);

        public JsonObject put(String key, Object val);

        public JsonObject remove(String key);

        /**  length / keys **/
        public int length();

        public Collection<String> keys();

        /** if has original mapping **/
        public Object original();

        /** clone a Json Object **/
        //        public JsonObject clone();
    }

    public static interface JsonArray {
        /** read string into JsonArray **/
        public JsonArray read(String s);

        /** write JsonArray int string **/
        public String toString();

        /** length / get / add / insert / remove **/
        public int length();

        public Object get(int i);

        public JsonArray add(Object s);

        public JsonArray remove(int i);

        public JsonArray set(int i, Object s);

        /** directly read string array as Json Array object. **/
        public JsonArray convert(String[] arr);

        public JsonArray convert(Collection<String> arr);

        /** clone a Json array **/
        //        public JsonArray clone();

        /** if has original mapping **/
        public Object original();
    }

    public static interface NewProxy {
        public JsonArray newArray();

        public JsonObject newObject();
    }

    /** static methods for read / is / convert **/

    public static JsonArray convertArray(String[] arr) {
        return newArray().convert(arr);
    }

    public static JsonArray convertArray(Collection<String> arr) {
        return newArray().convert(arr);
    }

    public static JsonArray readArray(String s) {
        return newArray().read(s);
    }

    public static JsonObject readObject(String s) {
        return newObject().read(s);
    }

    public static boolean isArray(Object obj) {
        if (obj instanceof JsonArray) {
            return true;
        }
        return false;
    }

    public static boolean isObject(Object obj) {
        if (obj instanceof JsonObject) {
            return true;
        }
        return false;
    }

    /** fill in the proxy **/

    public static JsonArray newArray() {
        return newProxy().newArray();
    }

    public static JsonObject newObject() {
        return newProxy().newObject();
    }

    //    public static NewProxy newProxy() {
    //        // FIXME: exchange other proxy
    //        return new MinimalJsonProxy();
    //    }

    public static NewProxy newProxy() {
        // FIXME: exchange other proxy
        return new JacksonJsonProxy();
    }

}