/*
* $Id: JSONValue.java,v 1.1 2006/04/15 14:37:04 platform Exp $
* Created on 2006-4-15
*/
package org.zkoss.json;
import java.io.Reader;
import java.io.StringReader;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.zkoss.json.parser.JSONParser;
/**
* Utilities to encode and decode data in JSON format.
* To decode, use {@link #parse(String)}.
* To encode, use {@link #toJSONString}.
* @author FangYidong<fangyidong@yahoo.com.cn>
*/
public class JSONValue {
/**
* Parse (a.k.a., decode) JSON text into java object from the input source.
*
* @param in the input to parse.
* @return Instance of the following:
* {@link JSONObject} (also java.util.Map),
* {@link JSONArray} (also java.util.List),
* java.lang.String,
* java.lang.Number,
* java.lang.Boolean,
* null.
* If in is null, null is returned.
*
*/
public static Object parse(Reader in) throws java.io.IOException {
if (in == null) return null;
JSONParser parser=new JSONParser();
return parser.parse(in);
}
/**
* Parse (a.k.a., decode) JSON text into java object from the string.
* @return the decoded object.
* If s is null, null is returned.
*/
public static Object parse(String s){
if (s == null) return null;
try {
StringReader in=new StringReader(s);
return parse(in);
} catch(java.io.IOException e){
throw new RuntimeException(e); //not possible
}
}
/**
* Convert (a.k.a., encode) 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.
*
* @param 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 Collection) //proposed enhancement F65-ZK-1866 use Collection instead of List
return JSONArray.toJSONString((Collection)value);
if (value.getClass().isArray()) {
if (value instanceof Object[])
return JSONArray.toJSONString((Object[])value);
if (value instanceof int[])
return JSONArray.toJSONString((int[])value);
if (value instanceof double[])
return JSONArray.toJSONString((double[])value);
if (value instanceof long[])
return JSONArray.toJSONString((long[])value);
if (value instanceof float[])
return JSONArray.toJSONString((float[])value);
if (value instanceof short[])
return JSONArray.toJSONString((short[])value);
if (value instanceof byte[])
return JSONArray.toJSONString((byte[])value);
if (value instanceof boolean[])
return JSONArray.toJSONString((boolean[])value);
if (value instanceof char[])
return JSONArray.toJSONString((char[])value);
}
if(value instanceof Enum) //proposed enhancement F65-ZK-1866 provide a default Enum conversion
return "\"" + escape(value.toString()) + "\"";
return value.toString();
}
/** Converts an integer to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(int value) {
return Integer.toString(value);
}
/** Converts a long to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(long value) {
return Long.toString(value);
}
/** Converts a short to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(short value) {
return Long.toString(value);
}
/** Converts a double to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(double value) {
return Double.toString(value);
}
/** Converts a float to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(float value) {
return Float.toString(value);
}
/** Converts a byte to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(byte value) {
return Byte.toString(value);
}
/** Converts a boolean to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(boolean value) {
return Boolean.toString(value);
}
/** Converts a char to JSON text
* <p>patched by tomyeh
*/
public static String toJSONString(char value) {
return toJSONString("" + value);
}
/**
* Escape quotes, \, /, \r, \n, \b, \f, \t and other control characters (U+0000 through U+001F).
* @param s
* @return the resulting string
*/
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/Unicode3.1.0/
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
}
}