軟件測試if else路徑開源代碼java中String.java中的toLowerCase方法

/**
     * Converts all of the characters in this <code>String</code> to lower
     * case using the rules of the given <code>Locale</code>.  Case mapping is based
     * on the Unicode Standard version specified by the {@link java.lang.Character Character}
     * class. Since case mappings are not always 1:1 char mappings, the resulting
     * <code>String</code> may be a different length than the original <code>String</code>.
     * <p>
     * Examples of lowercase  mappings are in the following table:
     * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description">
     * <tr>
     *   <th>Language Code of Locale</th>
     *   <th>Upper Case</th>
     *   <th>Lower Case</th>
     *   <th>Description</th>
     * </tr>
     * <tr>
     *   <td>tr (Turkish)</td>
     *   <td>&#92;u0130</td>
     *   <td>&#92;u0069</td>
     *   <td>capital letter I with dot above -&gt; small letter i</td>
     * </tr>
     * <tr>
     *   <td>tr (Turkish)</td>
     *   <td>&#92;u0049</td>
     *   <td>&#92;u0131</td>
     *   <td>capital letter I -&gt; small letter dotless i </td>
     * </tr>
     * <tr>
     *   <td>(all)</td>
     *   <td>French Fries</td>
     *   <td>french fries</td>
     *   <td>lowercased all chars in String</td>
     * </tr>
     * <tr>
     *   <td>(all)</td>
     *   <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi">
     *       <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil">
     *       <img src="doc-files/capsigma.gif" alt="capsigma"></td>
     *   <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi">
     *       <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon">
     *       <img src="doc-files/sigma1.gif" alt="sigma"></td>
     *   <td>lowercased all chars in String</td>
     * </tr>
     * </table>
     *
     * @param locale use the case transformation rules for this locale
     * @return the <code>String</code>, converted to lowercase.
     * @see     java.lang.String#toLowerCase()
     * @see     java.lang.String#toUpperCase()
     * @see     java.lang.String#toUpperCase(Locale)
     * @since   1.1
     */
    public String toLowerCase(Locale locale) {
        if (locale == null) {
            throw new NullPointerException();
        }


        int firstUpper;
        final int len = value.length;


        /* Now check if there are any characters that need to be changed. */
        scan: {
            for (firstUpper = 0 ; firstUpper < len; ) {
                char c = value[firstUpper];
                if ((c >= Character.MIN_HIGH_SURROGATE)
                        && (c <= Character.MAX_HIGH_SURROGATE)) {
                    int supplChar = codePointAt(firstUpper);
                    if (supplChar != Character.toLowerCase(supplChar)) {
                        break scan;
                    }
                    firstUpper += Character.charCount(supplChar);
                } else {
                    if (c != Character.toLowerCase(c)) {
                        break scan;
                    }
                    firstUpper++;
                }
            }
            return this;
        }


        char[] result = new char[len];
        int resultOffset = 0;  /* result may grow, so i+resultOffset
                                * is the write location in result */


        /* Just copy the first few lowerCase characters. */
        System.arraycopy(value, 0, result, 0, firstUpper);


        String lang = locale.getLanguage();
        boolean localeDependent =
                (lang == "tr" || lang == "az" || lang == "lt");
        char[] lowerCharArray;
        int lowerChar;
        int srcChar;
        int srcCount;
        for (int i = firstUpper; i < len; i += srcCount) {
            srcChar = (int)value[i];
            if ((char)srcChar >= Character.MIN_HIGH_SURROGATE
                    && (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
                srcChar = codePointAt(i);
                srcCount = Character.charCount(srcChar);
            } else {
                srcCount = 1;
            }
            if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA
                lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
            } else if (srcChar == '\u0130') { // LATIN CAPITAL LETTER I DOT
                lowerChar = Character.ERROR;
            } else {
                lowerChar = Character.toLowerCase(srcChar);
            }
            if ((lowerChar == Character.ERROR)
                    || (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
                if (lowerChar == Character.ERROR) {
                    if (!localeDependent && srcChar == '\u0130') {
                        lowerCharArray =
                                ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
                    } else {
                        lowerCharArray =
                                ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
                    }
                } else if (srcCount == 2) {
                    resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
                    continue;
                } else {
                    lowerCharArray = Character.toChars(lowerChar);
                }


                /* Grow result if needed */
                int mapLen = lowerCharArray.length;
                if (mapLen > srcCount) {
                    char[] result2 = new char[result.length + mapLen - srcCount];
                    System.arraycopy(result, 0, result2, 0, i + resultOffset);
                    result = result2;
                }
                for (int x = 0; x < mapLen; ++x) {
                    result[i + resultOffset + x] = lowerCharArray[x];
                }
                resultOffset += (mapLen - srcCount);
            } else {
                result[i + resultOffset] = (char)lowerChar;
            }
        }
        return new String(result, 0, len + resultOffset);
    }