com.ovea.tajin.json.Utils Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of tajin-framework Show documentation
There is a newer version: 1.0.b13
/**
 * Copyright (C) 2011 Ovea 
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.ovea.tajin.json;

/**
 * @author Mathieu Carbou ([email protected])
 */
final class Utils {

    /**
     * Produce a string from a double. The string "null" will be returned if
     * the number is not finite.
     *
     * @param d A double.
     * @return A String.
     */
    static public String doubleToString(double d) {
        if (Double.isInfinite(d) || Double.isNaN(d)) {
            return "null";
        }
        // Shave off trailing zeros and decimal point, if possible.
        String s = Double.toString(d);
        if (s.indexOf('.') > 0 && s.indexOf('e') < 0 && s.indexOf('E') < 0) {
            while (s.endsWith("0")) {
                s = s.substring(0, s.length() - 1);
            }
            if (s.endsWith(".")) {
                s = s.substring(0, s.length() - 1);
            }
        }
        return s;
    }


    static String quote(String string) {
        if (string == null || string.length() == 0) {
            return "\"\"";
        }

        char c;
        int i;
        int len = string.length();
        StringBuilder sb = new StringBuilder(len + 4);
        String t;

        sb.append('"');
        for (i = 0; i < len; i += 1) {
            c = string.charAt(i);
            switch (c) {
                case '\\':
                case '"':
                    sb.append('\\');
                    sb.append(c);
                    break;
                case '/':
//                if (b == '<') {
                    sb.append('\\');
//                }
                    sb.append(c);
                    break;
                case '\b':
                    sb.append("\\b");
                    break;
                case '\t':
                    sb.append("\\t");
                    break;
                case '\n':
                    sb.append("\\n");
                    break;
                case '\f':
                    sb.append("\\f");
                    break;
                case '\r':
                    sb.append("\\r");
                    break;
                default:
                    if (c < ' ') {
                        t = "000" + Integer.toHexString(c);
                        sb.append("\\u").append(t.substring(t.length() - 4));
                    } else {
                        sb.append(c);
                    }
            }
        }
        sb.append('"');
        return sb.toString();
    }

    /**
     * Throw an exception if the object is an NaN or infinite number.
     *
     * @param o The object to test.
     * @throws com.ovea.tajin.json.JSONException If o is a non-finite number.
     */
    static void testValidity(Object o) throws JSONException {
        if (o instanceof Double) {
            if (((Double) o).isInfinite() || ((Double) o).isNaN()) {
                throw new JSONException("JSON does not allow non-finite numbers.");
            }
        } else if (o instanceof Float) {
            if (((Float) o).isInfinite() || ((Float) o).isNaN()) {
                throw new JSONException("JSON does not allow non-finite numbers.");
            }
        }
    }

}