StringUtils.java

package com.hwlcn.security.util;

import java.text.ParseException;
import java.util.*;


public class StringUtils {

    public static final String EMPTY_STRING = "";

    public static final char DEFAULT_DELIMITER_CHAR = ',';

    public static final char DEFAULT_QUOTE_CHAR = '"';

    public static boolean hasText(String str) {
        if (!hasLength(str)) {
            return false;
        }
        int strLen = str.length();
        for (int i = 0; i < strLen; i++) {
            if (!Character.isWhitespace(str.charAt(i))) {
                return true;
            }
        }
        return false;
    }

    public static boolean hasLength(String str) {
        return (str != null && str.length() > 0);
    }



    public static boolean startsWithIgnoreCase(String str, String prefix) {
        if (str == null || prefix == null) {
            return false;
        }
        if (str.startsWith(prefix)) {
            return true;
        }
        if (str.length() < prefix.length()) {
            return false;
        }
        String lcStr = str.substring(0, prefix.length()).toLowerCase();
        String lcPrefix = prefix.toLowerCase();
        return lcStr.equals(lcPrefix);
    }

    public static String clean(String in) {
        String out = in;

        if (in != null) {
            out = in.trim();
            if (out.equals(EMPTY_STRING)) {
                out = null;
            }
        }

        return out;
    }


    public static String toString(Object[] array) {
        return toDelimitedString(array, ",");
    }

    public static String toDelimitedString(Object[] array, String delimiter) {
        if (array == null || array.length == 0) {
            return EMPTY_STRING;
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < array.length; i++) {
            if (i > 0) {
                sb.append(delimiter);
            }
            sb.append(array[i]);
        }
        return sb.toString();
    }

    public static String toDelimitedString(Collection c, String delimiter) {
        if (c == null || c.isEmpty()) {
            return EMPTY_STRING;
        }
        return join(c.iterator(), delimiter);
    }

    public static String[] tokenizeToStringArray(String str, String delimiters) {
        return tokenizeToStringArray(str, delimiters, true, true);
    }

    public static String[] tokenizeToStringArray(
            String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {

        if (str == null) {
            return null;
        }
        StringTokenizer st = new StringTokenizer(str, delimiters);
        List tokens = new ArrayList();
        while (st.hasMoreTokens()) {
            String token = st.nextToken();
            if (trimTokens) {
                token = token.trim();
            }
            if (!ignoreEmptyTokens || token.length() > 0) {
                tokens.add(token);
            }
        }
        return toStringArray(tokens);
    }


    public static String[] toStringArray(Collection collection) {
        if (collection == null) {
            return null;
        }
        return (String[]) collection.toArray(new String[collection.size()]);
    }

    public static String[] splitKeyValue(String aLine) throws ParseException {
        String line = clean(aLine);
        if (line == null) {
            return null;
        }
        String[] split = line.split(" ", 2);
        if (split.length != 2) {

            split = line.split("=", 2);
            if (split.length != 2) {
                String msg = "Unable to determine Key/Value pair from line [" + line + "].  There is no space from " +
                        "which the split location could be determined.";
                throw new ParseException(msg, 0);
            }

        }

        split[0] = clean(split[0]);
        split[1] = clean(split[1]);
        if (split[1].startsWith("=")) {

            split[1] = clean(split[1].substring(1));
        }

        if (split[0] == null) {
            String msg = "No valid key could be found in line [" + line + "] to form a key/value pair.";
            throw new ParseException(msg, 0);
        }
        if (split[1] == null) {
            String msg = "No corresponding value could be found in line [" + line + "] for key [" + split[0] + "]";
            throw new ParseException(msg, 0);
        }

        return split;
    }

    public static String[] split(String line) {
        return split(line, DEFAULT_DELIMITER_CHAR);
    }

    public static String[] split(String line, char delimiter) {
        return split(line, delimiter, DEFAULT_QUOTE_CHAR);
    }

    public static String[] split(String line, char delimiter, char quoteChar) {
        return split(line, delimiter, quoteChar, quoteChar);
    }

    public static String[] split(String line, char delimiter, char beginQuoteChar, char endQuoteChar) {
        return split(line, delimiter, beginQuoteChar, endQuoteChar, false, true);
    }


    public static String[] split(String aLine, char delimiter, char beginQuoteChar, char endQuoteChar,
                                 boolean retainQuotes, boolean trimTokens) {
        String line = clean(aLine);
        if (line == null) {
            return null;
        }

        List<String> tokens = new ArrayList<String>();
        StringBuilder sb = new StringBuilder();
        boolean inQuotes = false;

        for (int i = 0; i < line.length(); i++) {

            char c = line.charAt(i);
            if (c == beginQuoteChar) {
                if (inQuotes
                        && line.length() > (i + 1)
                        && line.charAt(i + 1) == beginQuoteChar) {
                    sb.append(line.charAt(i + 1));
                    i++;
                } else {
                    inQuotes = !inQuotes;
                    if (retainQuotes) {
                        sb.append(c);
                    }
                }
            } else if (c == endQuoteChar) {
                inQuotes = !inQuotes;
                if (retainQuotes) {
                    sb.append(c);
                }
            } else if (c == delimiter && !inQuotes) {
                String s = sb.toString();
                if (trimTokens) {
                    s = s.trim();
                }
                tokens.add(s);
                sb = new StringBuilder();
            } else {
                sb.append(c);
            }
        }
        String s = sb.toString();
        if (trimTokens) {
            s = s.trim();
        }
        tokens.add(s);
        return tokens.toArray(new String[tokens.size()]);
    }


    public static String join(Iterator<?> iterator, String separator) {
        final String empty = "";

        if (iterator == null) {
            return null;
        }
        if (!iterator.hasNext()) {
            return empty;
        }
        Object first = iterator.next();
        if (!iterator.hasNext()) {
            return first == null ? empty : first.toString();
        }

        StringBuilder buf = new StringBuilder(256);
        if (first != null) {
            buf.append(first);
        }

        while (iterator.hasNext()) {
            if (separator != null) {
                buf.append(separator);
            }
            Object obj = iterator.next();
            if (obj != null) {
                buf.append(obj);
            }
        }
        return buf.toString();
    }

    public static Set<String> splitToSet(String delimited, String separator) {
        if (delimited == null || separator == null) {
            return null;
        }
        String[] split = split(delimited, separator.charAt(0));
        return CollectionUtils.asSet(split);
    }

    public static String uppercaseFirstChar(String in) {
        if (in == null || in.length() == 0) {
            return in;
        }
        int length = in.length();
        StringBuilder sb = new StringBuilder(length);

        sb.append(Character.toUpperCase(in.charAt(0)));
        if (length > 1) {
            String remaining = in.substring(1);
            sb.append(remaining);
        }
        return sb.toString();
    }

}