StringUtils.java

package org.jcodec.common;

import java.lang.StringBuilder;
import java.util.ArrayList;
import java.util.List;

/**
 * This class is part of JCodec ( www.jcodec.org ) This software is distributed
 * under FreeBSD License
 * 
 * This code is borrowed from Apache Commons String Utils
 * 
 * @author The JCodec project
 */
public class StringUtils {

    private static String[] splitWorker4(String str, String separatorChars, int max, boolean preserveAllTokens) {
        // Performance tuned for 2.0 (JDK1.4)
        // Direct code is quicker than StringTokenizer.
        // Also, StringTokenizer uses isSpace() not isWhitespace()

        if (str == null) {
            return null;
        }
        int len = str.length();
        if (len == 0) {
            return new String[0];
        }
        List<String> list = new ArrayList<String>();
        int sizePlus1 = 1;
        int i = 0, start = 0;
        boolean match = false;
        boolean lastMatch = false;
        if (separatorChars == null) {
            // Null separator means use whitespace
            while (i < len) {
                if (Character.isWhitespace(str.charAt(i))) {
                    if (match || preserveAllTokens) {
                        lastMatch = true;
                        if (sizePlus1++ == max) {
                            i = len;
                            lastMatch = false;
                        }
                        list.add(str.substring(start, i));
                        match = false;
                    }
                    start = ++i;
                    continue;
                }
                lastMatch = false;
                match = true;
                i++;
            }
        } else if (separatorChars.length() == 1) {
            // Optimise 1 character case
            char sep = separatorChars.charAt(0);
            while (i < len) {
                if (str.charAt(i) == sep) {
                    if (match || preserveAllTokens) {
                        lastMatch = true;
                        if (sizePlus1++ == max) {
                            i = len;
                            lastMatch = false;
                        }
                        list.add(str.substring(start, i));
                        match = false;
                    }
                    start = ++i;
                    continue;
                }
                lastMatch = false;
                match = true;
                i++;
            }
        } else {
            // standard case
            while (i < len) {
                if (separatorChars.indexOf(str.charAt(i)) >= 0) {
                    if (match || preserveAllTokens) {
                        lastMatch = true;
                        if (sizePlus1++ == max) {
                            i = len;
                            lastMatch = false;
                        }
                        list.add(str.substring(start, i));
                        match = false;
                    }
                    start = ++i;
                    continue;
                }
                lastMatch = false;
                match = true;
                i++;
            }
        }
        if (match || (preserveAllTokens && lastMatch)) {
            list.add(str.substring(start, i));
        }
        return (String[]) list.toArray(new String[list.size()]);
    }

    private static String[] splitWorker(String str, char separatorChar, boolean preserveAllTokens) {
        // Performance tuned for 2.0 (JDK1.4)

        if (str == null) {
            return null;
        }
        int len = str.length();
        if (len == 0) {
            return new String[0];
        }
        List<String> list = new ArrayList<String>();
        int i = 0, start = 0;
        boolean match = false;
        boolean lastMatch = false;
        while (i < len) {
            if (str.charAt(i) == separatorChar) {
                if (match || preserveAllTokens) {
                    list.add(str.substring(start, i));
                    match = false;
                    lastMatch = true;
                }
                start = ++i;
                continue;
            }
            lastMatch = false;
            match = true;
            i++;
        }
        if (match || (preserveAllTokens && lastMatch)) {
            list.add(str.substring(start, i));
        }
        return (String[]) list.toArray(new String[list.size()]);
    }

    public static String[] split(String str) {
        return splitS3(str, null, -1);
    }

    public static String[] splitS(String str, String separatorChars) {
        return splitWorker4(str, separatorChars, -1, false);
    }

    public static String[] splitS3(String str, String separatorChars, int max) {
        return splitWorker4(str, separatorChars, max, false);
    }

    public static String[] splitC(String str, char separatorChar) {
        return splitWorker(str, separatorChar, false);
    }
    
    public static boolean isEmpty(String str) {
        return str == null || str.length() == 0;
    }
    
    private static boolean isDelimiter(char ch, char[] delimiters) {
        if (delimiters == null) {
            return Character.isWhitespace(ch);
        }
        for (int i = 0, isize = delimiters.length; i < isize; i++) {
            if (ch == delimiters[i]) {
                return true;
            }
        }
        return false;
    }
    
    public static String capitaliseAllWords(String str) {
        return capitalize(str);
    }
    
    public static String capitalize(String str) {
        return capitalizeD(str, null);
    }
    
    public static String capitalizeD(String str, char[] delimiters) {
        int delimLen = (delimiters == null ? -1 : delimiters.length);
        if (str == null || str.length() == 0 || delimLen == 0) {
            return str;
        }
        int strLen = str.length();
        StringBuilder buffer = new StringBuilder(strLen);
        boolean capitalizeNext = true;
        for (int i = 0; i < strLen; i++) {
            char ch = str.charAt(i);

            if (isDelimiter(ch, delimiters)) {
                buffer.append(ch);
                capitalizeNext = true;
            } else if (capitalizeNext) {
                buffer.append(Character.toTitleCase(ch));
                capitalizeNext = false;
            } else {
                buffer.append(ch);
            }
        }
        return buffer.toString();
    }
    
    

    public static String join(Object[] array) {
        return joinS(array, null);
    }

   
    public static String join2(Object[] array, char separator) {
        if (array == null) {
            return null;
        }

        return join4(array, separator, 0, array.length);
    }

    
    public static String join4(Object[] array, char separator, int startIndex, int endIndex) {
        if (array == null) {
            return null;
        }
        int bufSize = (endIndex - startIndex);
        if (bufSize <= 0) {
            return "";
        }

        bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length()) + 1);
        StringBuilder buf = new StringBuilder(bufSize);

        for (int i = startIndex; i < endIndex; i++) {
            if (i > startIndex) {
                buf.append(separator);
            }
            if (array[i] != null) {
                buf.append(array[i]);
            }
        }
        return buf.toString();
    }


    
    public static String joinS(Object[] array, String separator) {
        if (array == null) {
            return null;
        }
        return joinS4(array, separator, 0, array.length);
    }

   
    public static String joinS4(Object[] array, String separator, int startIndex, int endIndex) {
        if (array == null) {
            return null;
        }
        if (separator == null) {
            separator = "";
        }

        // endIndex - startIndex > 0:   Len = NofStrings *(len(firstString) + len(separator))
        //           (Assuming that all Strings are roughly equally long)
        int bufSize = (endIndex - startIndex);
        if (bufSize <= 0) {
            return "";
        }

        bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length())
                        + separator.length());

        StringBuilder buf = new StringBuilder(bufSize);

        for (int i = startIndex; i < endIndex; i++) {
            if (i > startIndex) {
                buf.append(separator);
            }
            if (array[i] != null) {
                buf.append(array[i]);
            }
        }
        return buf.toString();
    }
}