https://github.com/douglascrockford/JSON-java: JSON is a light-weight, language independent, data interchange format. See http://www.JSON.org/ The files in this package implement JSON encoders/decoders in Java. It also includes the capability to convert between JSON and XML, HTTP headers, Cookies, and CDL. This is a reference implementation. There is a large number of JSON packages in Java. Perhaps someday the Java community will standardize on one. Until then, choose carefully. The license includes this restriction: "The software shall be used for good, not evil." If your conscience cannot live with that, then choose a different package.
  • Douglas Crockford 
package org.json;

/*
Copyright (c) 2008 JSON.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/


This provides static methods to convert an XML text into a JSONArray or
JSONObject, and to covert a JSONArray or JSONObject into an XML text using
the JsonML transform.

Author:JSON.org
Version:2016-01-30
/**
 * This provides static methods to convert an XML text into a JSONArray or
 * JSONObject, and to covert a JSONArray or JSONObject into an XML text using
 * the JsonML transform.
 *
 * @author JSON.org
 * @version 2016-01-30
 */
public class JSONML {
    
Parse XML values and store them in a JSONArray.

Params:
  • x –       The XMLTokener containing the source string.
  • arrayForm – true if array form, false if object form.
  • ja –      The JSONArray that is containing the current tag or null
    if we are at the outermost level.
  • keepStrings – 	Don't type-convert text nodes and attribute values
Throws:
Returns:A JSONArray if the value is the outermost tag, otherwise null.
/**
     * Parse XML values and store them in a JSONArray.
     * @param x       The XMLTokener containing the source string.
     * @param arrayForm true if array form, false if object form.
     * @param ja      The JSONArray that is containing the current tag or null
     *     if we are at the outermost level.
     * @param keepStrings	Don't type-convert text nodes and attribute values
     * @return A JSONArray if the value is the outermost tag, otherwise null.
     * @throws JSONException
     */
    private static Object parse(
        XMLTokener x,
        boolean    arrayForm,
        JSONArray  ja,
        boolean keepStrings
    ) throws JSONException {
        String     attribute;
        char       c;
        String     closeTag = null;
        int        i;
        JSONArray  newja = null;
        JSONObject newjo = null;
        Object     token;
        String     tagName = null;

// Test for and skip past these forms:
//      <!-- ... -->
//      <![  ... ]]>
//      <!   ...   >
//      <?   ...  ?>

        while (true) {
            if (!x.more()) {
                throw x.syntaxError("Bad XML");
            }
            token = x.nextContent();
            if (token == XML.LT) {
                token = x.nextToken();
                if (token instanceof Character) {
                    if (token == XML.SLASH) {

// Close tag </

                        token = x.nextToken();
                        if (!(token instanceof String)) {
                            throw new JSONException(
                                    "Expected a closing name instead of '" +
                                    token + "'.");
                        }
                        if (x.nextToken() != XML.GT) {
                            throw x.syntaxError("Misshaped close tag");
                        }
                        return token;
                    } else if (token == XML.BANG) {

// <!

                        c = x.next();
                        if (c == '-') {
                            if (x.next() == '-') {
                                x.skipPast("-->");
                            } else {
                                x.back();
                            }
                        } else if (c == '[') {
                            token = x.nextToken();
                            if (token.equals("CDATA") && x.next() == '[') {
                                if (ja != null) {
                                    ja.put(x.nextCDATA());
                                }
                            } else {
                                throw x.syntaxError("Expected 'CDATA['");
                            }
                        } else {
                            i = 1;
                            do {
                                token = x.nextMeta();
                                if (token == null) {
                                    throw x.syntaxError("Missing '>' after '<!'.");
                                } else if (token == XML.LT) {
                                    i += 1;
                                } else if (token == XML.GT) {
                                    i -= 1;
                                }
                            } while (i > 0);
                        }
                    } else if (token == XML.QUEST) {

// <?

                        x.skipPast("?>");
                    } else {
                        throw x.syntaxError("Misshaped tag");
                    }

// Open tag <

                } else {
                    if (!(token instanceof String)) {
                        throw x.syntaxError("Bad tagName '" + token + "'.");
                    }
                    tagName = (String)token;
                    newja = new JSONArray();
                    newjo = new JSONObject();
                    if (arrayForm) {
                        newja.put(tagName);
                        if (ja != null) {
                            ja.put(newja);
                        }
                    } else {
                        newjo.put("tagName", tagName);
                        if (ja != null) {
                            ja.put(newjo);
                        }
                    }
                    token = null;
                    for (;;) {
                        if (token == null) {
                            token = x.nextToken();
                        }
                        if (token == null) {
                            throw x.syntaxError("Misshaped tag");
                        }
                        if (!(token instanceof String)) {
                            break;
                        }

// attribute = value

                        attribute = (String)token;
                        if (!arrayForm && ("tagName".equals(attribute) || "childNode".equals(attribute))) {
                            throw x.syntaxError("Reserved attribute.");
                        }
                        token = x.nextToken();
                        if (token == XML.EQ) {
                            token = x.nextToken();
                            if (!(token instanceof String)) {
                                throw x.syntaxError("Missing value");
                            }
                            newjo.accumulate(attribute, keepStrings ? ((String)token) :XML.stringToValue((String)token));
                            token = null;
                        } else {
                            newjo.accumulate(attribute, "");
                        }
                    }
                    if (arrayForm && newjo.length() > 0) {
                        newja.put(newjo);
                    }

// Empty tag <.../>

                    if (token == XML.SLASH) {
                        if (x.nextToken() != XML.GT) {
                            throw x.syntaxError("Misshaped tag");
                        }
                        if (ja == null) {
                            if (arrayForm) {
                                return newja;
                            }
                            return newjo;
                        }

// Content, between <...> and </...>

                    } else {
                        if (token != XML.GT) {
                            throw x.syntaxError("Misshaped tag");
                        }
                        closeTag = (String)parse(x, arrayForm, newja, keepStrings);
                        if (closeTag != null) {
                            if (!closeTag.equals(tagName)) {
                                throw x.syntaxError("Mismatched '" + tagName +
                                        "' and '" + closeTag + "'");
                            }
                            tagName = null;
                            if (!arrayForm && newja.length() > 0) {
                                newjo.put("childNodes", newja);
                            }
                            if (ja == null) {
                                if (arrayForm) {
                                    return newja;
                                }
                                return newjo;
                            }
                        }
                    }
                }
            } else {
                if (ja != null) {
                    ja.put(token instanceof String
                        ? keepStrings ? XML.unescape((String)token) :XML.stringToValue((String)token)
                        : token);
                }
            }
        }
    }


    
Convert a well-formed (but not necessarily valid) XML string into a
JSONArray using the JsonML transform. Each XML tag is represented as
a JSONArray in which the first element is the tag name. If the tag has
attributes, then the second element will be JSONObject containing the
name/value pairs. If the tag contains children, then strings and
JSONArrays will represent the child tags.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • string – The source string.
Throws:
Returns:A JSONArray containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONArray using the JsonML transform. Each XML tag is represented as
     * a JSONArray in which the first element is the tag name. If the tag has
     * attributes, then the second element will be JSONObject containing the
     * name/value pairs. If the tag contains children, then strings and
     * JSONArrays will represent the child tags.
     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param string The source string.
     * @return A JSONArray containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONArray
     */
    public static JSONArray toJSONArray(String string) throws JSONException {
        return (JSONArray)parse(new XMLTokener(string), true, null, false);
    }


    
Convert a well-formed (but not necessarily valid) XML string into a
JSONArray using the JsonML transform. Each XML tag is represented as
a JSONArray in which the first element is the tag name. If the tag has
attributes, then the second element will be JSONObject containing the
name/value pairs. If the tag contains children, then strings and
JSONArrays will represent the child tags.
As opposed to toJSONArray this method does not attempt to convert 
any text node or attribute value to any type 
but just leaves it as a string.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • string – The source string.
  • keepStrings – If true, then values will not be coerced into boolean
 or numeric values and will instead be left as strings
Throws:
Returns:A JSONArray containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONArray using the JsonML transform. Each XML tag is represented as
     * a JSONArray in which the first element is the tag name. If the tag has
     * attributes, then the second element will be JSONObject containing the
     * name/value pairs. If the tag contains children, then strings and
     * JSONArrays will represent the child tags.
     * As opposed to toJSONArray this method does not attempt to convert 
     * any text node or attribute value to any type 
     * but just leaves it as a string.
     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param string The source string.
     * @param keepStrings If true, then values will not be coerced into boolean
     *  or numeric values and will instead be left as strings
     * @return A JSONArray containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONArray
     */
    public static JSONArray toJSONArray(String string, boolean keepStrings) throws JSONException {
        return (JSONArray)parse(new XMLTokener(string), true, null, keepStrings);
    }


    
Convert a well-formed (but not necessarily valid) XML string into a
JSONArray using the JsonML transform. Each XML tag is represented as
a JSONArray in which the first element is the tag name. If the tag has
attributes, then the second element will be JSONObject containing the
name/value pairs. If the tag contains children, then strings and
JSONArrays will represent the child content and tags.
As opposed to toJSONArray this method does not attempt to convert 
any text node or attribute value to any type 
but just leaves it as a string.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • x – An XMLTokener.
  • keepStrings – If true, then values will not be coerced into boolean
 or numeric values and will instead be left as strings
Throws:
Returns:A JSONArray containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONArray using the JsonML transform. Each XML tag is represented as
     * a JSONArray in which the first element is the tag name. If the tag has
     * attributes, then the second element will be JSONObject containing the
     * name/value pairs. If the tag contains children, then strings and
     * JSONArrays will represent the child content and tags.
     * As opposed to toJSONArray this method does not attempt to convert 
     * any text node or attribute value to any type 
     * but just leaves it as a string.
     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param x An XMLTokener.
     * @param keepStrings If true, then values will not be coerced into boolean
     *  or numeric values and will instead be left as strings
     * @return A JSONArray containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONArray
     */
    public static JSONArray toJSONArray(XMLTokener x, boolean keepStrings) throws JSONException {
        return (JSONArray)parse(x, true, null, keepStrings);
    }


    
Convert a well-formed (but not necessarily valid) XML string into a
JSONArray using the JsonML transform. Each XML tag is represented as
a JSONArray in which the first element is the tag name. If the tag has
attributes, then the second element will be JSONObject containing the
name/value pairs. If the tag contains children, then strings and
JSONArrays will represent the child content and tags.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • x – An XMLTokener.
Throws:
Returns:A JSONArray containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONArray using the JsonML transform. Each XML tag is represented as
     * a JSONArray in which the first element is the tag name. If the tag has
     * attributes, then the second element will be JSONObject containing the
     * name/value pairs. If the tag contains children, then strings and
     * JSONArrays will represent the child content and tags.
     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param x An XMLTokener.
     * @return A JSONArray containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONArray
     */
    public static JSONArray toJSONArray(XMLTokener x) throws JSONException {
        return (JSONArray)parse(x, true, null, false);
    }


    
Convert a well-formed (but not necessarily valid) XML string into a
JSONObject using the JsonML transform. Each XML tag is represented as
a JSONObject with a "tagName" property. If the tag has attributes, then
the attributes will be in the JSONObject as properties. If the tag
contains children, the object will have a "childNodes" property which
will be an array of strings and JsonML JSONObjects.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • string – The XML source text.
Throws:
Returns:A JSONObject containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONObject using the JsonML transform. Each XML tag is represented as
     * a JSONObject with a "tagName" property. If the tag has attributes, then
     * the attributes will be in the JSONObject as properties. If the tag
     * contains children, the object will have a "childNodes" property which
     * will be an array of strings and JsonML JSONObjects.

     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param string The XML source text.
     * @return A JSONObject containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONObject
     */
    public static JSONObject toJSONObject(String string) throws JSONException {
        return (JSONObject)parse(new XMLTokener(string), false, null, false);
    }
    
    
    
Convert a well-formed (but not necessarily valid) XML string into a
JSONObject using the JsonML transform. Each XML tag is represented as
a JSONObject with a "tagName" property. If the tag has attributes, then
the attributes will be in the JSONObject as properties. If the tag
contains children, the object will have a "childNodes" property which
will be an array of strings and JsonML JSONObjects.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • string – The XML source text.
  • keepStrings – If true, then values will not be coerced into boolean
 or numeric values and will instead be left as strings
Throws:
Returns:A JSONObject containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONObject using the JsonML transform. Each XML tag is represented as
     * a JSONObject with a "tagName" property. If the tag has attributes, then
     * the attributes will be in the JSONObject as properties. If the tag
     * contains children, the object will have a "childNodes" property which
     * will be an array of strings and JsonML JSONObjects.

     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param string The XML source text.
     * @param keepStrings If true, then values will not be coerced into boolean
     *  or numeric values and will instead be left as strings
     * @return A JSONObject containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONObject
     */
    public static JSONObject toJSONObject(String string, boolean keepStrings) throws JSONException {
        return (JSONObject)parse(new XMLTokener(string), false, null, keepStrings);
    }

    
    
Convert a well-formed (but not necessarily valid) XML string into a
JSONObject using the JsonML transform. Each XML tag is represented as
a JSONObject with a "tagName" property. If the tag has attributes, then
the attributes will be in the JSONObject as properties. If the tag
contains children, the object will have a "childNodes" property which
will be an array of strings and JsonML JSONObjects.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • x – An XMLTokener of the XML source text.
Throws:
Returns:A JSONObject containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONObject using the JsonML transform. Each XML tag is represented as
     * a JSONObject with a "tagName" property. If the tag has attributes, then
     * the attributes will be in the JSONObject as properties. If the tag
     * contains children, the object will have a "childNodes" property which
     * will be an array of strings and JsonML JSONObjects.

     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param x An XMLTokener of the XML source text.
     * @return A JSONObject containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONObject
     */
    public static JSONObject toJSONObject(XMLTokener x) throws JSONException {
           return (JSONObject)parse(x, false, null, false);
    }


    
Convert a well-formed (but not necessarily valid) XML string into a
JSONObject using the JsonML transform. Each XML tag is represented as
a JSONObject with a "tagName" property. If the tag has attributes, then
the attributes will be in the JSONObject as properties. If the tag
contains children, the object will have a "childNodes" property which
will be an array of strings and JsonML JSONObjects.
Comments, prologs, DTDs, and <[ [ ]]> are ignored.

Params:
  • x – An XMLTokener of the XML source text.
  • keepStrings – If true, then values will not be coerced into boolean
 or numeric values and will instead be left as strings
Throws:
Returns:A JSONObject containing the structured data from the XML string.
/**
     * Convert a well-formed (but not necessarily valid) XML string into a
     * JSONObject using the JsonML transform. Each XML tag is represented as
     * a JSONObject with a "tagName" property. If the tag has attributes, then
     * the attributes will be in the JSONObject as properties. If the tag
     * contains children, the object will have a "childNodes" property which
     * will be an array of strings and JsonML JSONObjects.

     * Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
     * @param x An XMLTokener of the XML source text.
     * @param keepStrings If true, then values will not be coerced into boolean
     *  or numeric values and will instead be left as strings
     * @return A JSONObject containing the structured data from the XML string.
     * @throws JSONException Thrown on error converting to a JSONObject
     */
    public static JSONObject toJSONObject(XMLTokener x, boolean keepStrings) throws JSONException {
           return (JSONObject)parse(x, false, null, keepStrings);
    }


    
Reverse the JSONML transformation, making an XML text from a JSONArray.

Params:
  • ja – A JSONArray.
Throws:
Returns:An XML string.
/**
     * Reverse the JSONML transformation, making an XML text from a JSONArray.
     * @param ja A JSONArray.
     * @return An XML string.
     * @throws JSONException Thrown on error converting to a string
     */
    public static String toString(JSONArray ja) throws JSONException {
        int                 i;
        JSONObject          jo;
        int                 length;
        Object              object;
        StringBuilder        sb = new StringBuilder();
        String              tagName;

// Emit <tagName

        tagName = ja.getString(0);
        XML.noSpace(tagName);
        tagName = XML.escape(tagName);
        sb.append('<');
        sb.append(tagName);

        object = ja.opt(1);
        if (object instanceof JSONObject) {
            i = 2;
            jo = (JSONObject)object;

// Emit the attributes

            // Don't use the new entrySet API to maintain Android support
            for (final String key : jo.keySet()) {
                final Object value = jo.opt(key);
                XML.noSpace(key);
                if (value != null) {
                    sb.append(' ');
                    sb.append(XML.escape(key));
                    sb.append('=');
                    sb.append('"');
                    sb.append(XML.escape(value.toString()));
                    sb.append('"');
                }
            }
        } else {
            i = 1;
        }

// Emit content in body

        length = ja.length();
        if (i >= length) {
            sb.append('/');
            sb.append('>');
        } else {
            sb.append('>');
            do {
                object = ja.get(i);
                i += 1;
                if (object != null) {
                    if (object instanceof String) {
                        sb.append(XML.escape(object.toString()));
                    } else if (object instanceof JSONObject) {
                        sb.append(toString((JSONObject)object));
                    } else if (object instanceof JSONArray) {
                        sb.append(toString((JSONArray)object));
                    } else {
                        sb.append(object.toString());
                    }
                }
            } while (i < length);
            sb.append('<');
            sb.append('/');
            sb.append(tagName);
            sb.append('>');
        }
        return sb.toString();
    }

    
Reverse the JSONML transformation, making an XML text from a JSONObject.
The JSONObject must contain a "tagName" property. If it has children,
then it must have a "childNodes" property containing an array of objects.
The other properties are attributes with string values.

Params:
  • jo – A JSONObject.
Throws:
Returns:An XML string.
/**
     * Reverse the JSONML transformation, making an XML text from a JSONObject.
     * The JSONObject must contain a "tagName" property. If it has children,
     * then it must have a "childNodes" property containing an array of objects.
     * The other properties are attributes with string values.
     * @param jo A JSONObject.
     * @return An XML string.
     * @throws JSONException Thrown on error converting to a string
     */
    public static String toString(JSONObject jo) throws JSONException {
        StringBuilder sb = new StringBuilder();
        int                 i;
        JSONArray           ja;
        int                 length;
        Object              object;
        String              tagName;
        Object              value;

//Emit <tagName

        tagName = jo.optString("tagName");
        if (tagName == null) {
            return XML.escape(jo.toString());
        }
        XML.noSpace(tagName);
        tagName = XML.escape(tagName);
        sb.append('<');
        sb.append(tagName);

//Emit the attributes

        // Don't use the new entrySet API to maintain Android support
        for (final String key : jo.keySet()) {
            if (!"tagName".equals(key) && !"childNodes".equals(key)) {
                XML.noSpace(key);
                value = jo.opt(key);
                if (value != null) {
                    sb.append(' ');
                    sb.append(XML.escape(key));
                    sb.append('=');
                    sb.append('"');
                    sb.append(XML.escape(value.toString()));
                    sb.append('"');
                }
            }
        }

//Emit content in body

        ja = jo.optJSONArray("childNodes");
        if (ja == null) {
            sb.append('/');
            sb.append('>');
        } else {
            sb.append('>');
            length = ja.length();
            for (i = 0; i < length; i += 1) {
                object = ja.get(i);
                if (object != null) {
                    if (object instanceof String) {
                        sb.append(XML.escape(object.toString()));
                    } else if (object instanceof JSONObject) {
                        sb.append(toString((JSONObject)object));
                    } else if (object instanceof JSONArray) {
                        sb.append(toString((JSONArray)object));
                    } else {
                        sb.append(object.toString());
                    }
                }
            }
            sb.append('<');
            sb.append('/');
            sb.append(tagName);
            sb.append('>');
        }
        return sb.toString();
    }
}