    001package org.apache.commons.ssl.asn1;
    002
    003import java.io.ByteArrayOutputStream;
    004import java.util.Vector;
    005
    006public final class Strings {
    007    public static String fromUTF8ByteArray(byte[] bytes) {
    008        int i = 0;
    009        int length = 0;
    010
    011        while (i < bytes.length) {
    012            length++;
    013            if ((bytes[i] & 0xf0) == 0xf0) {
    014                // surrogate pair
    015                length++;
    016                i += 4;
    017            } else if ((bytes[i] & 0xe0) == 0xe0) {
    018                i += 3;
    019            } else if ((bytes[i] & 0xc0) == 0xc0) {
    020                i += 2;
    021            } else {
    022                i += 1;
    023            }
    024        }
    025
    026        char[] cs = new char[length];
    027
    028        i = 0;
    029        length = 0;
    030
    031        while (i < bytes.length) {
    032            char ch;
    033
    034            if ((bytes[i] & 0xf0) == 0xf0) {
    035                int codePoint = ((bytes[i] & 0x03) << 18) | ((bytes[i + 1] & 0x3F) << 12) | ((bytes[i + 2] & 0x3F) << 6) | (bytes[i + 3] & 0x3F);
    036                int U = codePoint - 0x10000;
    037                char W1 = (char) (0xD800 | (U >> 10));
    038                char W2 = (char) (0xDC00 | (U & 0x3FF));
    039                cs[length++] = W1;
    040                ch = W2;
    041                i += 4;
    042            } else if ((bytes[i] & 0xe0) == 0xe0) {
    043                ch = (char) (((bytes[i] & 0x0f) << 12)
    044                             | ((bytes[i + 1] & 0x3f) << 6) | (bytes[i + 2] & 0x3f));
    045                i += 3;
    046            } else if ((bytes[i] & 0xd0) == 0xd0) {
    047                ch = (char) (((bytes[i] & 0x1f) << 6) | (bytes[i + 1] & 0x3f));
    048                i += 2;
    049            } else if ((bytes[i] & 0xc0) == 0xc0) {
    050                ch = (char) (((bytes[i] & 0x1f) << 6) | (bytes[i + 1] & 0x3f));
    051                i += 2;
    052            } else {
    053                ch = (char) (bytes[i] & 0xff);
    054                i += 1;
    055            }
    056
    057            cs[length++] = ch;
    058        }
    059
    060        return new String(cs);
    061    }
    062
    063    public static byte[] toUTF8ByteArray(String string) {
    064        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
    065        char[] c = string.toCharArray();
    066        int i = 0;
    067
    068        while (i < c.length) {
    069            char ch = c[i];
    070
    071            if (ch < 0x0080) {
    072                bOut.write(ch);
    073            } else if (ch < 0x0800) {
    074                bOut.write(0xc0 | (ch >> 6));
    075                bOut.write(0x80 | (ch & 0x3f));
    076            }
    077            // surrogate pair
    078            else if (ch >= 0xD800 && ch <= 0xDFFF) {
    079                // in error - can only happen, if the Java String class has a
    080                // bug.
    081                if (i + 1 >= c.length) {
    082                    throw new IllegalStateException("invalid UTF-16 codepoint");
    083                }
    084                char W1 = ch;
    085                ch = c[++i];
    086                char W2 = ch;
    087                // in error - can only happen, if the Java String class has a
    088                // bug.
    089                if (W1 > 0xDBFF) {
    090                    throw new IllegalStateException("invalid UTF-16 codepoint");
    091                }
    092                int codePoint = (((W1 & 0x03FF) << 10) | (W2 & 0x03FF)) + 0x10000;
    093                bOut.write(0xf0 | (codePoint >> 18));
    094                bOut.write(0x80 | ((codePoint >> 12) & 0x3F));
    095                bOut.write(0x80 | ((codePoint >> 6) & 0x3F));
    096                bOut.write(0x80 | (codePoint & 0x3F));
    097            } else {
    098                bOut.write(0xe0 | (ch >> 12));
    099                bOut.write(0x80 | ((ch >> 6) & 0x3F));
    100                bOut.write(0x80 | (ch & 0x3F));
    101            }
    102
    103            i++;
    104        }
    105
    106        return bOut.toByteArray();
    107    }
    108
    109    /**
    110     * A locale independent version of toUpperCase.
    111     *
    112     * @param string input to be converted
    113     * @return a US Ascii uppercase version
    114     */
    115    public static String toUpperCase(String string) {
    116        boolean changed = false;
    117        char[] chars = string.toCharArray();
    118
    119        for (int i = 0; i != chars.length; i++) {
    120            char ch = chars[i];
    121            if ('a' <= ch && 'z' >= ch) {
    122                changed = true;
    123                chars[i] = (char) (ch - 'a' + 'A');
    124            }
    125        }
    126
    127        if (changed) {
    128            return new String(chars);
    129        }
    130
    131        return string;
    132    }
    133
    134    /**
    135     * A locale independent version of toLowerCase.
    136     *
    137     * @param string input to be converted
    138     * @return a US ASCII lowercase version
    139     */
    140    public static String toLowerCase(String string) {
    141        boolean changed = false;
    142        char[] chars = string.toCharArray();
    143
    144        for (int i = 0; i != chars.length; i++) {
    145            char ch = chars[i];
    146            if ('A' <= ch && 'Z' >= ch) {
    147                changed = true;
    148                chars[i] = (char) (ch - 'A' + 'a');
    149            }
    150        }
    151
    152        if (changed) {
    153            return new String(chars);
    154        }
    155
    156        return string;
    157    }
    158
    159    public static byte[] toByteArray(String string) {
    160        byte[] bytes = new byte[string.length()];
    161
    162        for (int i = 0; i != bytes.length; i++) {
    163            char ch = string.charAt(i);
    164
    165            bytes[i] = (byte) ch;
    166        }
    167
    168        return bytes;
    169    }
    170
    171    public static String[] split(String input, char delimiter) {
    172        Vector v = new Vector();
    173        boolean moreTokens = true;
    174        String subString;
    175
    176        while (moreTokens) {
    177            int tokenLocation = input.indexOf(delimiter);
    178            if (tokenLocation > 0) {
    179                subString = input.substring(0, tokenLocation);
    180                v.addElement(subString);
    181                input = input.substring(tokenLocation + 1);
    182            } else {
    183                moreTokens = false;
    184                v.addElement(input);
    185            }
    186        }
    187
    188        String[] res = new String[v.size()];
    189
    190        for (int i = 0; i != res.length; i++) {
    191            res[i] = (String) v.elementAt(i);
    192        }
    193        return res;
    194    }
    195}