001/* ============
002 * Orson Charts
003 * ============
004 * 
005 * (C)opyright 2013, 2014, by Object Refinery Limited.
006 * 
007 * http://www.object-refinery.com/orsoncharts/index.html
008 * 
009 * JSON.simple
010 * -----------
011 * The code in this file originates from the JSON.simple project by 
012 * FangYidong<fangyidong@yahoo.com.cn>:
013 * 
014 *     https://code.google.com/p/json-simple/
015 *  
016 * which is licensed under the Apache Software License version 2.0.  
017 * 
018 * It has been modified locally and repackaged under 
019 * com.orsoncharts.util.json.* to avoid conflicts with any other version that
020 * may be present on the classpath. 
021 * 
022 */
023
024package com.orsoncharts.util.json;
025
026import java.io.IOException;
027import java.io.Writer;
028import java.util.HashMap;
029import java.util.Iterator;
030import java.util.Map;
031
032/**
033 * A JSON object. Key value pairs are unordered.
034 */
035public class JSONObject extends HashMap implements Map, JSONAware, 
036        JSONStreamAware {
037    
038    private static final long serialVersionUID = -503443796854799292L;
039
040    /**
041     * Encode a map into JSON text and write it to out.
042     * If this map is also a {@link JSONAware} or {@link JSONStreamAware}, 
043     * {@code JSONAware} or {@code JSONStreamAware} specific 
044     * behaviours will be ignored at this top level.
045     * 
046     * @see com.orsoncharts.util.json.JSONValue#writeJSONString(Object, Writer)
047     * 
048     * @param map  the map to write ({@code null} permitted).
049     * @param out  the output writer ({@code null} not permitted).
050     * 
051     * @throws IOException if there is an I/O problem.
052     */
053    public static void writeJSONString(Map map, Writer out) throws IOException {
054        if (map == null) {
055            out.write("null");
056            return;
057        }
058        boolean first = true;
059        Iterator iter = map.entrySet().iterator();
060        out.write('{');
061        while (iter.hasNext()) {
062            if (first) {
063                first = false;
064            }
065            else {
066                out.write(',');
067            }
068            Map.Entry entry = (Map.Entry) iter.next();
069            out.write('\"');
070            out.write(JSONValue.escape(String.valueOf(entry.getKey())));
071            out.write('\"');
072            out.write(':');
073            JSONValue.writeJSONString(entry.getValue(), out);
074        }
075        out.write('}');
076    }
077
078    /**
079     * Writes a JSON string representing this object instance to the specified
080     * output writer.
081     * 
082     * @param out  the output writer ({@code null} not permitted).
083     * 
084     * @throws IOException if there is an I/O problem.
085     */
086    @Override
087    public void writeJSONString(Writer out) throws IOException {
088        writeJSONString(this, out);
089    }
090    
091    /**
092     * Convert a map to JSON text. The result is a JSON object. 
093     * If this map is also a {@link JSONAware}, {@code JSONAware} specific 
094     * behaviours will be omitted at this top level.
095     * 
096     * @see com.orsoncharts.util.json.JSONValue#toJSONString(Object)
097     * 
098     * @param map  the map ({@code null} permitted).
099     * 
100     * @return JSON text, or "null" if map is null.
101     */
102    public static String toJSONString(Map map){
103        if (map == null) {
104            return "null";
105        }
106        
107        StringBuffer sb = new StringBuffer();
108        boolean first = true;
109        Iterator iter = map.entrySet().iterator();
110        
111        sb.append('{');
112        while (iter.hasNext()) {
113            if (first) {
114                first = false;
115            }
116            else {
117                sb.append(',');
118            }
119            
120            Map.Entry entry = (Map.Entry) iter.next();
121            toJSONString(String.valueOf(entry.getKey()), entry.getValue(), sb);
122        }
123        sb.append('}');
124        return sb.toString();
125    }
126    
127    /**
128     * Returns a JSON string representing this object.
129     * 
130     * @return A JSON string. 
131     */
132    @Override
133    public String toJSONString(){
134        return toJSONString(this);
135    }
136    
137    /**
138     * Writes a key and value to a JSON string.
139     * 
140     * @param key  the key ({@code null} permitted).
141     * @param value  the value ({@code null} permitted).
142     * @param sb  a string buffer ({@code null} not permitted).
143     * 
144     * @return A JSON string fragment representing the key and value. 
145     */
146    private static String toJSONString(String key, Object value, 
147            StringBuffer sb) {
148        sb.append('\"');
149        if (key == null) {
150            sb.append("null");
151        }
152        else {
153            JSONValue.escape(key, sb);
154        }
155        sb.append('\"').append(':');
156        
157        sb.append(JSONValue.toJSONString(value));
158        
159        return sb.toString();
160    }
161    
162    /**
163     * Returns a string representation of this object.
164     * 
165     * @return A string. 
166     */
167    @Override
168    public String toString(){
169        return toJSONString();
170    }
171
172    /**
173     * Returns a JSON string fragment containing the key and value.
174     * 
175     * @param key  the key ({@code null} permitted).
176     * @param value  the value ({@code null} permitted).
177     * 
178     * @return A JSON string fragment. 
179     */
180    public static String toString(String key, Object value){
181        StringBuffer sb = new StringBuffer();
182        toJSONString(key, value, sb);
183        return sb.toString();
184    }
185}