sailing-analytics/java/org.json.simple/src/org/json/simple/JSONValue.java

/*
 * $Id: JSONValue.java,v 1.1 2006/04/15 14:37:04 platform Exp $
 * Created on 2006-4-15
 */
package org.json.simple;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.Writer;
import java.net.URL;
import java.util.List;
import java.util.Map;

import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

/**
 * @author FangYidong<fangyidong@yahoo.com.cn>
 */
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 org.json.simple.parser.JSONParser#parse(Reader)
     * @see #parseWithException(Reader)
     * 
     * @param in
     * @return Instance of the following: org.json.simple.JSONObject, org.json.simple.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;
        }
    }

    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 org.json.simple.parser.JSONParser
     * 
     * @param in
     * @return Instance of the following: org.json.simple.JSONObject, org.json.simple.JSONArray, java.lang.String,
     *         java.lang.Number, java.lang.Boolean, null
     * 
     * @throws IOException
     * @throws ParseException
     */
    public static Object parseWithException(Reader in) throws IOException, ParseException {
        JSONParser parser = new JSONParser();
        return parser.parse(in);
    }

    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 Map or a List, and it's also a JSONStreamAware or a JSONAware, JSONStreamAware or 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.json.simple.JSONObject#writeJSONString(Map, Writer)
     * @see org.json.simple.JSONArray#writeJSONString(List, Writer)
     * 
     * @param value
     * @param writer
     */
    @SuppressWarnings("unchecked")
    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<Object, Object>) value, out);
            return;
        }

        if (value instanceof List) {
            JSONArray.writeJSONString((List<?>) value, out);
            return;
        }

        if (value instanceof URL) {
            out.write('\"');
            out.write(value.toString());
            out.write('\"');
            return;
        }

        if (value instanceof Enum) {
            out.write('\"');
            out.write(value.toString());
            out.write('\"');
            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.json.simple.JSONObject#toJSONString(Map)
     * @see org.json.simple.JSONArray#toJSONString(List)
     * 
     * @param value
     * @return JSON text, or "null" if value is null or it's an NaN or an INF number.
     */
    @SuppressWarnings("unchecked")
    public static String toJSONString(Object value) {
        if (value == null)
            return "null";

        if (value instanceof String)
            return "\"" + escape((String) value) + "\"";

        if (value instanceof Double) {
            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<Object, Object>) value);

        if (value instanceof List)
            return JSONArray.toJSONString((List<?>) value);

        if (value instanceof Enum) {
            return '\"' + value.toString() + '\"';
        }

        return value.toString();
    }

    /**
     * Escape quotes, \, /, \r, \n, \b, \f, \t and other control characters (U+0000 through U+001F).
     * 
     * @param s
     * @return
     */
    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
    }

}