Merge pull request #1894 from buddhini81/master

Code for article BAEL-839

core-java/src/main/java/com/baeldung/regexp/EscapingChars.java

@@ -0,0 +1,25 @@
+package com.baeldung.regexp;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class EscapingChars {
+    public boolean isMatching(String input, String pattern) {
+        return input.matches(pattern);
+    }
+
+    public int splitAndCountWords(String input, String pattern) {
+        return input.split(pattern).length;
+    }
+
+    public int splitAndCountWordsUsingQuoteMethod(String input, String pattern) {
+        return input.split(Pattern.quote(pattern)).length;
+    }
+
+    public String changeCurrencySymbol(String input, String pattern,
+            String correctStr) {
+        Pattern p = Pattern.compile(pattern);
+        Matcher m = p.matcher(input);
+        return m.replaceAll(correctStr);
+    }
+}

core-java/src/test/java/com/baeldung/regexp/EscapingCharsManualTest.java

@@ -0,0 +1,70 @@
+package com.baeldung.regexp;
+
+import static junit.framework.TestCase.assertEquals;
+
+import org.junit.Test;
+
+public class EscapingCharsManualTest {
+    @Test
+    public void givenRegexWithDot_whenMatchingStr_thenMatches() {
+        String strInput = "foof";
+        String strRegex = "foo.";
+        EscapingChars e = new EscapingChars();
+
+        assertEquals(true, e.isMatching(strInput, strRegex));
+    }
+
+    @Test
+    public void givenRegexWithDotEsc_whenMatchingStr_thenNotMatching() {
+        String strInput = "foof";
+        String strRegex = "foo\\.";
+        EscapingChars e = new EscapingChars();
+
+        assertEquals(false, e.isMatching(strInput, strRegex));
+    }
+
+    @Test
+    public void givenRegexWithPipeEscaped_whenSplitStr_thenSplits() {
+        String strInput = "foo|bar|hello|world";
+        String strRegex = "\\Q|\\E";
+        EscapingChars e = new EscapingChars();
+
+        assertEquals(4, e.splitAndCountWords(strInput, strRegex));
+    }
+
+    @Test
+    public void givenRegexWithPipeEscQuoteMeth_whenSplitStr_thenSplits() {
+        String strInput = "foo|bar|hello|world";
+        String strRegex = "|";
+        EscapingChars e = new EscapingChars();
+
+        assertEquals(4,
+                e.splitAndCountWordsUsingQuoteMethod(strInput, strRegex));
+    }
+
+    @Test
+    public void givenRegexWithDollar_whenReplacing_thenNotReplace() {
+        String strInput = "I gave $50 to my brother."
+                + "He bought candy for $35. Now he has $15 left.";
+        String strRegex = "$";
+        String strReplacement = "£";
+        String output = "I gave £50 to my brother."
+                + "He bought candy for £35. Now he has £15 left.";
+        EscapingChars e = new EscapingChars();
+
+        assertEquals(output,
+                e.changeCurrencySymbol(strInput, strRegex, strReplacement));
+    }
+
+    @Test
+    public void givenRegexWithDollarEsc_whenReplacing_thenReplace() {
+        String strInput = "I gave $50 to my brother. He bought candy for $35. Now he has $15 left.";
+        String strRegex = "\\$";
+        String strReplacement = "£";
+        String output = "I gave £50 to my brother. He bought candy for £35. Now he has £15 left.";
+        EscapingChars e = new EscapingChars();
+
+        assertEquals(output,
+                e.changeCurrencySymbol(strInput, strRegex, strReplacement));
+    }
+}