--- a/java/sql-dk/src/info/globalcode/sql/dk/Functions.java Tue Dec 24 00:12:53 2013 +0100
+++ b/java/sql-dk/src/info/globalcode/sql/dk/Functions.java Tue Dec 24 00:15:04 2013 +0100
@@ -133,4 +133,29 @@
Arrays.fill(array, ch);
return new String(array);
}
+
+ /**
+ * @param original any text
+ * @return escaped text that can be used as part of an regular expression, matches the original
+ * text
+ */
+ public static String escapeRegEx(String original) {
+ StringBuilder escaped = new StringBuilder(original.length() * 3);
+
+ escaped.append("\\Q"); // start quotation
+ for (int i = 0; i < original.length(); i++) {
+ char ch = original.charAt(i);
+ if (ch == 'E' && i > 0 && original.charAt(i - 1) == '\\') {
+ escaped.append(ch); // this unintentionally ends quotation
+ escaped.append("\\\\E"); // insert escaped \E (eaten before)
+ escaped.append("\\Q"); // re-start quotation
+ } else {
+ escaped.append(ch);
+ }
+
+ }
+ escaped.append("\\E"); // end quotation
+
+ return escaped.toString();
+ }
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/java/sql-dk/test/info/globalcode/sql/dk/FunctionsTest.java Tue Dec 24 00:15:04 2013 +0100
@@ -0,0 +1,59 @@
+/**
+ * SQL-DK
+ * Copyright © 2013 František Kučera (frantovo.cz)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+package info.globalcode.sql.dk;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import org.testng.annotations.Test;
+import static org.testng.Assert.*;
+
+/**
+ *
+ * @author Ing. František Kučera (frantovo.cz)
+ */
+public class FunctionsTest {
+
+ @Test
+ public void testEscapeRegEx() {
+ for (String original : new String[]{"abcd", "1234", "xxx", "\\Eescape\\Q", "\\Qescape\\E", "abc\\Eescape\\Qdef.", ".", ""}) {
+ String patternString = Functions.escapeRegEx(original);
+ System.out.println(original + " → " + patternString);
+
+ Pattern pattern = Pattern.compile(patternString);
+
+ String testString;
+ Matcher m;
+
+ testString = original;
+ m = pattern.matcher(testString);
+ assertTrue(m.matches(), "Pattern does not match original string: " + testString);
+
+ testString = original + "x";
+ m = pattern.matcher(testString);
+ assertFalse(m.matches(), "Pattern matches wrong string: " + testString);
+
+ testString = "x" + original;
+ m = pattern.matcher(testString);
+ assertFalse(m.matches(), "Pattern matches wrong string: " + testString);
+
+ testString = (original + "ab").substring(1);
+ m = pattern.matcher(testString);
+ assertFalse(m.matches(), "Pattern matches wrong string: " + testString);
+ }
+ }
+}