pl.nask.hsn2.jsontemplate.formatters.JsStringFormatter.java Source code

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Here is the source code for pl.nask.hsn2.jsontemplate.formatters.JsStringFormatter.java

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/*
 * Copyright (c) NASK, NCSC
 *
 * This file is part of HoneySpider Network 2.1.
 *
 * This is a free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
    
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
    
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package pl.nask.hsn2.jsontemplate.formatters;

import jsontemplate.IFormatter;

import org.json.simple.JSONValue;

public class JsStringFormatter implements IFormatter {

    @Override
    public final Object format(Object value) {
        String jsonString = JSONValue.toJSONString(value);
        String result = escapeSlashAndUnicode(jsonString);

        // If value is Number result will be JSON number, which means no quotation marks. Return value has to be JSON
        // text, so it have to be enclosed within quotation marks.
        if (!result.startsWith("\"")) {
            result = "\"" + result + "\"";
        }

        return result;
    }

    // This code was taken from org.apache.commons.jexl2.parser.StringParser (org.apache.commons-jexl:2.0.1) and
    // modified

    /** The length of an escaped unicode sequence. */
    private static final int UCHAR_LEN = 4;

    /** The last 7bits ascii character. */
    private static final char LAST_ASCII = 127;

    private static String escapeSlashAndUnicode(String str) {
        if (str == null) {
            return null;
        }
        final int length = str.length();
        StringBuilder strb = new StringBuilder(length);

        for (int i = 0; i < length; ++i) {
            char c = str.charAt(i);
            if (c < LAST_ASCII) {
                if (c == '\\') {
                    int next = i + 1;
                    if (next < length && str.charAt(next) == 'u') {
                        strb.append('\\');
                        strb.append('\\');
                        continue;
                    }
                }
                strb.append(c);
            } else {
                strb.append('\\');
                strb.append('\\');
                strb.append('u');
                String hex = Integer.toHexString(c);
                for (int h = hex.length(); h < UCHAR_LEN; ++h) {
                    strb.append('0');
                }
                strb.append(hex);
            }
        }
        return strb.toString();
    }
}