From c8c501b8bcb06a3be56f23bc5c415eea63442f21 Mon Sep 17 00:00:00 2001 From: lado Date: Wed, 26 Oct 2011 13:04:55 +0200 Subject: striped stringutils from commons --- .../src/de/bjusystems/vdrmanager/StringUtils.java | 151 +++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 vdrmanager/src/de/bjusystems/vdrmanager/StringUtils.java (limited to 'vdrmanager/src/de') diff --git a/vdrmanager/src/de/bjusystems/vdrmanager/StringUtils.java b/vdrmanager/src/de/bjusystems/vdrmanager/StringUtils.java new file mode 100644 index 0000000..23f1845 --- /dev/null +++ b/vdrmanager/src/de/bjusystems/vdrmanager/StringUtils.java @@ -0,0 +1,151 @@ +package de.bjusystems.vdrmanager; + +import java.util.ArrayList; +import java.util.List; + + +public class StringUtils { + + /** + * An empty immutable String array. + */ + public static final String[] EMPTY_STRING_ARRAY = new String[0]; + + + /** + * Performs the logic for the split and + * splitPreserveAllTokens methods that return a maximum array + * length. + * + * @param str the String to parse, may be null + * @param separatorChars the separate character + * @param max the maximum number of elements to include in the + * array. A zero or negative value implies no limit. + * @param preserveAllTokens if true, adjacent separators are + * treated as empty token separators; if false, adjacent + * separators are treated as one separator. + * @return an array of parsed Strings, null if null String input + */ + private static String[] splitWorker(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 EMPTY_STRING_ARRAY; + } + List list = new ArrayList(); + 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()]); + } + + /** + *

Splits the provided text into an array, separators specified, + * preserving all tokens, including empty tokens created by adjacent + * separators. This is an alternative to using StringTokenizer.

+ * + *

The separator is not included in the returned String array. + * Adjacent separators are treated as separators for empty tokens. + * For more control over the split use the StrTokenizer class.

+ * + *

A null input String returns null. + * A null separatorChars splits on whitespace.

+ * + *
+     * StringUtils.splitPreserveAllTokens(null, *)           = null
+     * StringUtils.splitPreserveAllTokens("", *)             = []
+     * StringUtils.splitPreserveAllTokens("abc def", null)   = ["abc", "def"]
+     * StringUtils.splitPreserveAllTokens("abc def", " ")    = ["abc", "def"]
+     * StringUtils.splitPreserveAllTokens("abc  def", " ")   = ["abc", "", def"]
+     * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":")   = ["ab", "cd", "ef"]
+     * StringUtils.splitPreserveAllTokens("ab:cd:ef:", ":")  = ["ab", "cd", "ef", ""]
+     * StringUtils.splitPreserveAllTokens("ab:cd:ef::", ":") = ["ab", "cd", "ef", "", ""]
+     * StringUtils.splitPreserveAllTokens("ab::cd:ef", ":")  = ["ab", "", cd", "ef"]
+     * StringUtils.splitPreserveAllTokens(":cd:ef", ":")     = ["", cd", "ef"]
+     * StringUtils.splitPreserveAllTokens("::cd:ef", ":")    = ["", "", cd", "ef"]
+     * StringUtils.splitPreserveAllTokens(":cd:ef:", ":")    = ["", cd", "ef", ""]
+     * 
+ * + * @param str the String to parse, may be null + * @param separatorChars the characters used as the delimiters, + * null splits on whitespace + * @return an array of parsed Strings, null if null String input + * @since 2.1 + */ + public static String[] splitPreserveAllTokens(String str, String separatorChars) { + return splitWorker(str, separatorChars, -1, true); + } + +} -- cgit v1.2.3