striped stringutils from commons

1 files changed, 151 insertions, 0 deletions

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 <code>String</code> array.
+     */
+    public static final String[] EMPTY_STRING_ARRAY = new String[0];
+
+    
+    /**
+     * Performs the logic for the <code>split</code> and 
+     * <code>splitPreserveAllTokens</code> methods that return a maximum array 
+     * length.
+     *
+     * @param str  the String to parse, may be <code>null</code>
+     * @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 <code>true</code>, adjacent separators are
+     * treated as empty token separators; if <code>false</code>, adjacent
+     * separators are treated as one separator.
+     * @return an array of parsed Strings, <code>null</code> 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()]);
+    }
+    
+    /**
+     * <p>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.</p>
+     *
+     * <p>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.</p>
+     *
+     * <p>A <code>null</code> input String returns <code>null</code>.
+     * A <code>null</code> separatorChars splits on whitespace.</p>
+     *
+     * <pre>
+     * 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", ""]
+     * </pre>
+     *
+     * @param str  the String to parse, may be <code>null</code>
+     * @param separatorChars  the characters used as the delimiters,
+     *  <code>null</code> splits on whitespace
+     * @return an array of parsed Strings, <code>null</code> if null String input
+     * @since 2.1
+     */
+    public static String[] splitPreserveAllTokens(String str, String separatorChars) {
+        return splitWorker(str, separatorChars, -1, true);
+    }
+
+}