A Generic method to modify the names in a JSONObject

This is a method to use configuration to modify the filed names of a JSON string.

You can use this function to do the following work:

1. rename a field of the JSON string

2. delete a field which not needed

3. rename a nested sub-JSON field

The logic is like this: 

1. Take a configuration file which is a JSON string and convert it into JSONObject. An incomingKey you defined here means this field or it's sub-fields are needed to be modified.

2. Read the JSON string which need to be modified as input.

3. Call the method to do the rename work, , loop all the fields of the configuration JOSNObject, use ecah of the incomingKey to get the object, if needRemoval is true, then delete this field. if needRemoval is false, and the outgoingKey exsits, then rename this field.

4. Do regression, until all the fields in the configuration file are done.

Here comes the code.

package com.judd.tools;import net.sf.json.JSONArray;import net.sf.json.JSONObject;import static net.sf.json.JSONObject.fromObject;public class JSONRenameUtils {public static String renameJSONFields(String rawJSONString) throws Exception {JSONObject mapJSONObject = JSONNameMappingLoader.getNameMappings();JSONObject rawJSONObject = fromObject(rawJSONString);doRenameWork(rawJSONObject, mapJSONObject);return rawJSONObject.toString();}private static void doRenameWork(JSONObject targetObj, JSONObject mapObj) {if (mapObj.containsKey(Consts.SUB_JSON_OBJECT)) {JSONArray children = (JSONArray) mapObj.get(Consts.SUB_JSON_OBJECT);for (Object obj : children.toArray()) {JSONObject jsonObj = (JSONObject) obj;String incomingKey = jsonObj.optString(Consts.INCOMING_KEY);String outgoingKey = null;boolean needRemoval = Boolean.valueOf(jsonObj.optString(Consts.NEED_REMOVAL));;if (jsonObj.containsKey(Consts.OUTGOING_KEY)) {outgoingKey = jsonObj.optString(Consts.OUTGOING_KEY);}if (needRemoval) {targetObj.remove(incomingKey);continue;}Object removed = targetObj.get(incomingKey);if (outgoingKey != null) {targetObj.remove(incomingKey);targetObj.put(outgoingKey, removed);} else {removed = targetObj.get(incomingKey);}if (removed instanceof JSONObject) {doRenameWork((JSONObject) removed, jsonObj);if (outgoingKey != null) {targetObj.put(outgoingKey, removed);} else {targetObj.put(incomingKey, removed);}}else if(removed instanceof JSONArray){for (Object object : ((JSONArray)removed).toArray()) {JSONObject jsonObjectInArray = (JSONObject) object;doRenameWork(jsonObjectInArray, jsonObj);}}}}}}

package com.cobra.sankes;import java.io.IOException;import net.sf.json.JSONObject;import net.sf.json.JSONSerializer;public final class JSONNameMappingLoader {    public static final String MAPPING_FILE = <span style="font-family: Arial, Helvetica, sans-serif;">"YOUR CONFIGURATION FILE PATH HERE"</span>;    private static final JSONObject NAME_MAPPINGS;    static {    JSONObject jsonObject = null;        try {        jsonObject = loadNameMappings();        } catch (IOException e) {        }        NAME_MAPPINGS = jsonObject;    }    private JSONNameMappingLoader() {        super();    }    public static JSONObject getNameMappings() {        return NAME_MAPPINGS;    }    private static JSONObject loadNameMappings() throws IOException {        String mappingData = ResourcesLoader.readFileByChars(MAPPING_FILE);System.out.println(mappingData);        JSONObject jsonData = (JSONObject) JSONSerializer.toJSON(mappingData);        return jsonData;    }}

package com.cobra.sankes;import java.io.File;import java.io.FileInputStream;import java.io.InputStreamReader;import java.io.Reader;public final class ResourcesLoader {private ResourcesLoader() {super();}    public static String readFileByChars(String fileName) {        File file = new File(fileName);        Reader reader = null;        StringBuilder builder = new StringBuilder();;        try {            reader = new InputStreamReader(new FileInputStream(file));            int tempchar;            while ((tempchar = reader.read()) != -1) {                if (((char) tempchar) != '\r') {                builder.append((char) tempchar);                }            }            reader.close();        } catch (Exception e) {            e.printStackTrace();        }        return builder.toString();    }}

package com.cobra.sankes;public final class Consts {

<span style="white-space:pre"></span>private Consts(){

<span style="white-space:pre"></span>super();

<span style="white-space:pre"></span>}public static final String INCOMING_KEY = "incomingKey";public static final String OUTGOING_KEY = "outgoingKey";public static final String NEED_REMOVAL = "needRemoval";public static final String SUB_JSON_OBJECT = "children";}

And the configuration file should looks like this:

{"children": [{"incomingKey": "original name","needRemoval": false,"outgoingKey": "final name"},{"incomingKey": "original name","children": [{"incomingKey": "original name","needRemoval": true,"outgoingKey": "final name"},{"incomingKey": "original name","outgoingKey": "final name","children": [{"incomingKey": "original name","needRemoval": false,"outgoingKey": "final name"}]}]}]}

Here if "outgoingKey" is omitted, means this field name will not be renamed, it was just be used as a path to find it's sub set.
if   "needRemoval" is omitted, means this field will not be removed. You can not define it if you want to keep the field because this field's default value is false in the code above.

Here is one simple example of it.

Input here:

{"testing" : "a json string","sample" : "do it","widget" : {"debug" : "on","window" : [{"title": "array1","name": "main_window","width": 500,"height": 500},{"title": "array2","name": "main_window","width": 500,"height": 500}],"image" : {"src": "Images/Sun.png","name": "sun1","hOffset": 250,"vOffset": 250,"alignment": "center"},"text": {"data": "Click Here","size": 36,"style": "bold","name": "text1","hOffset": 250,"vOffset": 100,"alignment": "center","onMouseUp": "sun1.opacity = (sun1.opacity / 100) * 90;"}}}    

Configuration file here:

{"children": [{"incomingKey": "sample","needRemoval": false,"outgoingKey": "This is a sample"},{"incomingKey": "widget","children": [{"incomingKey": "debug","needRemoval": false,"outgoingKey": "debug is bit of pain"},{"incomingKey": "image","needRemoval": true},{"incomingKey": "window","needRemoval": false,"children": [{"incomingKey": "title","needRemoval": false,"outgoingKey": "TITLE",},{"incomingKey": "name","needRemoval": false,"outgoingKey": "NAME"}]},{"incomingKey": "text","outgoingKey": "what? I am not a text!","children": [{"incomingKey": "size","needRemoval": false,"outgoingKey": "Which size do you like the most? C, C#, C++?"}]}]}]}

This is aiming at to delete "image" object, and to rename "sample", "debug", "text", "text/size", "window/title"

Output here:

{"testing": "a json string","widget": {"window": [{"width": 500,"height": 500,"TITLE": "array1","NAME": "main_window"},{"width": 500,"height": 500,"TITLE": "array2","NAME": "main_window"}],"debug is bit of pain": "on","what? I am not a text!": {"data": "Click Here","style": "bold","name": "text1","hOffset": 250,"vOffset": 100,"alignment": "center","onMouseUp": "sun1.opacity = (sun1.opacity / 100) * 90;","Which size do you like the most? C, C#, C++?": 36}},"This is a sample": "do it"}