JSONValue.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, by David Gilbert and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* JSON.simple
* -----------
* The code in this file originates from the JSON.simple project by
* FangYidong<fangyidong@yahoo.com.cn>:
*
* https://code.google.com/p/json-simple/
*
* which is licensed under the Apache Software License version 2.0.
*
* It has been modified locally and repackaged under
* org.jfree.data.json.impl.* to avoid conflicts with any other version that
* may be present on the classpath.
*
*/
package org.jfree.data.json.impl;
import java.io.IOException;
import java.io.Writer;
import java.util.List;
import java.util.Map;
/**
* Utility methods for JSON values.
* <br><br>
* This class is for internal use by JFreeChart, it is not
* part of the supported API and you should not call it directly. If you need
* JSON support in your project you should include JSON.simple
* (https://code.google.com/p/json-simple/) or some other JSON library directly
* in your project.
*/
public class JSONValue {
// /**
// * Parse JSON text into java object from the input source.
// * Please use parseWithException() if you don't want to ignore the
// * exception.
// *
// * @see com.orsoncharts.util.json.parser.JSONParser#parse(Reader)
// * @see #parseWithException(Reader)
// *
// * @param in the input reader.
// * @return Instance of the following:
// * com.orsoncharts.util.json.JSONObject,
// * com.orsoncharts.util.json.JSONArray,
// * java.lang.String,
// * java.lang.Number,
// * java.lang.Boolean,
// * null
// */
// public static Object parse(Reader in){
// try {
// JSONParser parser = new JSONParser();
// return parser.parse(in);
// }
// catch (Exception e) {
// return null;
// }
// }
//
// /**
// * Parses an object from a string.
// *
// * @param s the string.
// *
// * @return An object.
// */
// public static Object parse(String s){
// StringReader in = new StringReader(s);
// return parse(in);
// }
//
// /**
// * Parse JSON text into java object from the input source.
// *
// * @see com.orsoncharts.util.json.parser.JSONParser
// *
// * @param in the input reader ({@code null} not permitted).
// *
// * @return Instance of the following:
// * com.orsoncharts.util.json.JSONObject,
// * com.orsoncharts.util.json.JSONArray,
// * java.lang.String,
// * java.lang.Number,
// * java.lang.Boolean,
// * null
// *
// * @throws IOException if there is an I/O problem.
// * @throws ParseException if there is a parsing problem.
// */
// public static Object parseWithException(Reader in) throws IOException,
// ParseException{
// JSONParser parser = new JSONParser();
// return parser.parse(in);
// }
//
// /**
// * Parses an object from a JSON string.
// *
// * @param s the string.
// *
// * @return An object.
// *
// * @throws ParseException if there is a parsing problem.
// */
// public static Object parseWithException(String s) throws ParseException{
// JSONParser parser = new JSONParser();
// return parser.parse(s);
// }
/**
* Encode an object into JSON text and write it to out.
* <p>
* If this object is a {@code Map} or a {@code List}, and it's
* also a {@link JSONStreamAware} or a {@link JSONAware},
* {@code JSONStreamAware} or {@code JSONAware} will be
* considered firstly.
* <p>
* DO NOT call this method from writeJSONString(Writer) of a class that
* implements both JSONStreamAware and (Map or List) with
* "this" as the first parameter, use JSONObject.writeJSONString(Map,
* Writer) or JSONArray.writeJSONString(List, Writer) instead.
*
* @see org.jfree.data.json.impl.JSONObject#writeJSONString(Map, Writer)
* @see org.jfree.data.json.impl.JSONArray#writeJSONString(List, Writer)
*
* @param value the value.
* @param out the output writer.
* @throws IOException if there is an I/O problem.
*/
public static void writeJSONString(Object value, Writer out)
throws IOException {
if (value == null) {
out.write("null");
return;
}
if (value instanceof String) {
out.write('\"');
out.write(escape((String) value));
out.write('\"');
return;
}
if (value instanceof Double) {
if(((Double) value).isInfinite() || ((Double) value).isNaN()) {
out.write("null");
}
else {
out.write(value.toString());
}
return;
}
if (value instanceof Float) {
if (((Float) value).isInfinite() || ((Float) value).isNaN()) {
out.write("null");
}
else {
out.write(value.toString());
}
return;
}
if (value instanceof Number) {
out.write(value.toString());
return;
}
if (value instanceof Boolean) {
out.write(value.toString());
return;
}
if ((value instanceof JSONStreamAware)) {
((JSONStreamAware) value).writeJSONString(out);
return;
}
if ((value instanceof JSONAware)) {
out.write(((JSONAware) value).toJSONString());
return;
}
if (value instanceof Map) {
JSONObject.writeJSONString((Map) value, out);
return;
}
if (value instanceof List) {
JSONArray.writeJSONString((List) value, out);
return;
}
out.write(value.toString());
}
/**
* Convert an object to JSON text.
* <p>
* If this object is a Map or a List, and it's also a JSONAware, JSONAware
* will be considered firstly.
* <p>
* DO NOT call this method from toJSONString() of a class that implements
* both JSONAware and Map or List with
* "this" as the parameter, use JSONObject.toJSONString(Map) or
* JSONArray.toJSONString(List) instead.
*
* @see org.jfree.data.json.impl.JSONObject#toJSONString(Map)
* @see org.jfree.data.json.impl.JSONArray#toJSONString(List)
*
* @param value the value.
* @return JSON text, or "null" if value is null or it's an NaN or an INF
* number.
*/
public static String toJSONString(Object value){
if (value == null) {
return "null";
}
if (value instanceof String) {
return "\"" + escape((String) value) + "\"";
}
if (value instanceof Double){
if(((Double) value).isInfinite() || ((Double) value).isNaN()) {
return "null";
}
else {
return value.toString();
}
}
if (value instanceof Float) {
if (((Float) value).isInfinite() || ((Float) value).isNaN()) {
return "null";
}
else {
return value.toString();
}
}
if (value instanceof Number) {
return value.toString();
}
if (value instanceof Boolean) {
return value.toString();
}
if ((value instanceof JSONAware)) {
return ((JSONAware) value).toJSONString();
}
if (value instanceof Map) {
return JSONObject.toJSONString((Map) value);
}
if (value instanceof List) {
return JSONArray.toJSONString((List) value);
}
return value.toString();
}
/**
* Escape quotes, \, /, \r, \n, \b, \f, \t and other control characters
* (U+0000 through U+001F).
*
* @param s the string to be escaped ({@code null} permitted).
*
* @return A string.
*/
public static String escape(String s) {
if (s == null) {
return null;
}
StringBuffer sb = new StringBuffer();
escape(s, sb);
return sb.toString();
}
/**
* @param s - Must not be null.
* @param sb
*/
static void escape(String s, StringBuffer sb) {
for(int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
switch(ch){
case '"':
sb.append("\\\"");
break;
case '\\':
sb.append("\\\\");
break;
case '\b':
sb.append("\\b");
break;
case '\f':
sb.append("\\f");
break;
case '\n':
sb.append("\\n");
break;
case '\r':
sb.append("\\r");
break;
case '\t':
sb.append("\\t");
break;
case '/':
sb.append("\\/");
break;
default:
//Reference: http://www.unicode.org/versions/Unicode5.1.0/
if ((ch >= '\u0000' && ch <= '\u001F')
|| (ch >= '\u007F' && ch <= '\u009F')
|| (ch >= '\u2000' && ch <= '\u20FF')) {
String ss = Integer.toHexString(ch);
sb.append("\\u");
for (int k = 0; k < 4 - ss.length(); k++) {
sb.append('0');
}
sb.append(ss.toUpperCase());
}
else {
sb.append(ch);
}
}
}//for
}
}