stringutils.java

我费了好大劲才找到的一款非常全的OA办公自动化软件源码

/*
 Copyright (C) 2002-2004 MySQL AB

 This program is free software; you can redistribute it and/or modify
 it under the terms of version 2 of the GNU General Public License as
 published by the Free Software Foundation.
 

 There are special exceptions to the terms and conditions of the GPL 
 as it is applied to this software. View the full text of the 
 exception exception in file EXCEPTIONS-CONNECTOR-J in the directory of this 
 software distribution.

 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, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */
package com.mysql.jdbc;

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;

import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;


/**
 * Various utility methods for converting to/from byte arrays in the platform
 * encoding
 *
 * @author Mark Matthews
 */
public class StringUtils {
    private static final int BYTE_RANGE = (1 + Byte.MAX_VALUE) - Byte.MIN_VALUE;
    private static byte[] allBytes = new byte[BYTE_RANGE];
    private static char[] byteToChars = new char[BYTE_RANGE];

    static {
        for (int i = Byte.MIN_VALUE; i <= Byte.MAX_VALUE; i++) {
            allBytes[i - Byte.MIN_VALUE] = (byte) i;
        }

        String allBytesString = new String(allBytes, 0,
                Byte.MAX_VALUE - Byte.MIN_VALUE);

        int allBytesStringLen = allBytesString.length();

        for (int i = 0;
                (i < (Byte.MAX_VALUE - Byte.MIN_VALUE))
                && (i < allBytesStringLen); i++) {
            byteToChars[i] = allBytesString.charAt(i);
        }
    }

    /**
     * Returns the byte[] representation of the given string using given
     * encoding.
     *
     * @param s the string to convert
     * @param encoding the character encoding to use
     * @param serverEncoding DOCUMENT ME!
     * @param parserKnowsUnicode DOCUMENT ME!
     *
     * @return byte[] representation of the string
     *
     * @throws UnsupportedEncodingException if an encoding unsupported by the
     *         JVM is supplied.
     */
    public static final byte[] getBytes(String s, String encoding,
        String serverEncoding, boolean parserKnowsUnicode)
        throws UnsupportedEncodingException {
        SingleByteCharsetConverter converter = SingleByteCharsetConverter
            .getInstance(encoding);

        return getBytes(s, converter, encoding, serverEncoding,
            parserKnowsUnicode);
    }

    /**
     * Returns the byte[] representation of the given string (re)using the
     * given charset converter, and the given encoding.
     *
     * @param s the string to convert
     * @param converter the converter to reuse
     * @param encoding the character encoding to use
     * @param serverEncoding DOCUMENT ME!
     * @param parserKnowsUnicode DOCUMENT ME!
     *
     * @return byte[] representation of the string
     *
     * @throws UnsupportedEncodingException if an encoding unsupported by the
     *         JVM is supplied.
     */
    public static final byte[] getBytes(String s,
        SingleByteCharsetConverter converter, String encoding,
        String serverEncoding, boolean parserKnowsUnicode)
        throws UnsupportedEncodingException {
        byte[] b = null;

        if (converter != null) {
            b = converter.toBytes(s);
        } else if (encoding == null) {
            b = s.getBytes();
        } else {
            b = s.getBytes(encoding);

            if (!parserKnowsUnicode
                    && (encoding.equalsIgnoreCase("SJIS")
                    || encoding.equalsIgnoreCase("BIG5")
                    || encoding.equalsIgnoreCase("GBK"))) {
                if (!encoding.equalsIgnoreCase(serverEncoding)) {
                    b = escapeEasternUnicodeByteStream(b, s, 0, s.length());
                }
            }
        }

        return b;
    }

    /**
     * DOCUMENT ME!
     *
     * @param s DOCUMENT ME!
     * @param converter DOCUMENT ME!
     * @param encoding DOCUMENT ME!
     * @param serverEncoding DOCUMENT ME!
     * @param offset DOCUMENT ME!
     * @param length DOCUMENT ME!
     * @param parserKnowsUnicode DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws UnsupportedEncodingException DOCUMENT ME!
     */
    public static final byte[] getBytes(String s,
        SingleByteCharsetConverter converter, String encoding,
        String serverEncoding, int offset, int length,
        boolean parserKnowsUnicode) throws UnsupportedEncodingException {
        byte[] b = null;

        if (converter != null) {
            b = converter.toBytes(s, offset, length);
        } else if (encoding == null) {
            byte[] temp = s.getBytes();

            b = new byte[length];
            System.arraycopy(temp, offset, b, 0, length);
        } else {
            byte[] temp = s.getBytes(encoding);

            b = new byte[length];
            System.arraycopy(temp, offset, b, 0, length);

            if (!parserKnowsUnicode
                    && (encoding.equalsIgnoreCase("SJIS")
                    || encoding.equalsIgnoreCase("BIG5")
                    || encoding.equalsIgnoreCase("GBK"))) {
                if (!encoding.equalsIgnoreCase(serverEncoding)) {
                    b = escapeEasternUnicodeByteStream(b, s, offset, length);
                }
            }
        }

        return b;
    }

    /**
     * Dumps the given bytes to STDOUT as a hex dump (up to length bytes).
     *
     * @param byteBuffer the data to print as hex
     * @param length the number of bytes to print
     */
    public static final void dumpAsHex(byte[] byteBuffer, int length) {
        int p = 0;
        int rows = length / 8;

        for (int i = 0; i < rows; i++) {
            int ptemp = p;

            for (int j = 0; j < 8; j++) {
                String hexVal = Integer.toHexString((int) byteBuffer[ptemp]
                        & 0xff);

                if (hexVal.length() == 1) {
                    hexVal = "0" + hexVal;
                }

                System.out.print(hexVal + " ");
                ptemp++;
            }

            System.out.print("    ");

            for (int j = 0; j < 8; j++) {
                if ((byteBuffer[p] > 32) && (byteBuffer[p] < 127)) {
                    System.out.print((char) byteBuffer[p] + " ");
                } else {
                    System.out.print(". ");
                }

                p++;
            }

            System.out.println();
        }

        int n = 0;

        for (int i = p; i < length; i++) {
            String hexVal = Integer.toHexString((int) byteBuffer[i] & 0xff);

            if (hexVal.length() == 1) {
                hexVal = "0" + hexVal;
            }

            System.out.print(hexVal + " ");
            n++;
        }

        for (int i = n; i < 8; i++) {
            System.out.print("   ");
        }

        System.out.print("    ");

        for (int i = p; i < length; i++) {
            if ((byteBuffer[i] > 32) && (byteBuffer[i] < 127)) {
                System.out.print((char) byteBuffer[i] + " ");
            } else {
                System.out.print(". ");
            }
        }

        System.out.println();
    }

    /**
     * Returns the bytes as an ASCII String.
     *
     * @param buffer the bytes representing the string
     *
     * @return The ASCII String.
     */
    public static final String toAsciiString(byte[] buffer) {