Added Java implementation

Seregy · Seregy · commit c8fcab42ace9 · 2017-05-18T02:18:27.000+03:00
diff --git a/Java/Match.java b/Java/Match.java
@@ -0,0 +1,42 @@
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Example of using regular expressions for finding strings.
+ */
+public final class Match {
+
+    /**
+     * Private constructor prevents class from being instantiated.
+     */
+    private Match() {
+
+    }
+
+    /**
+     * Entry point of the program.
+     *
+     * @param args command-line arguments, not used
+     */
+    public static void main(final String[] args) {
+        String input1 = "My email is someones@mail.com";
+        String input2 = "My email is not@mail";
+        String regularExpression = "[^\\s]+@[^\\s]+\\.[^\\s]+";
+
+        Pattern pattern = Pattern.compile(regularExpression);
+
+        Matcher matcher1 = pattern.matcher(input1);
+        String output1 = "Nothing was found";
+        if (matcher1.find()) {
+            output1 = matcher1.group();
+        }
+        System.out.println(output1);
+
+        Matcher matcher2 = pattern.matcher(input2);
+        String output2 = "Nothing was found";
+        if (matcher2.find()) {
+            output2 = matcher2.group();
+        }
+        System.out.println(output2);
+    }
+}
diff --git a/Java/Replace.java b/Java/Replace.java
@@ -0,0 +1,37 @@
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Example of using regular expressions for replacing strings.
+ */
+public final class Replace {
+
+    /**
+     * Private constructor prevents class from being instantiated.
+     */
+    private Replace() {
+
+    }
+
+    /**
+     * Entry point of the program.
+     *
+     * @param args command-line arguments, not used
+     */
+    public static void main(final String[] args) {
+        //Using String API
+        String regularExpression1 = "abc";
+        String input1 = "abcdefg";
+        String output1 = input1.replaceAll(regularExpression1, "123");
+        System.out.println(output1);
+
+        // Using regex API
+        String regularExpression2 = "abc";
+        String input2 = "abcdefgABCDEFG";
+        Pattern pattern = Pattern.compile(regularExpression2,
+                Pattern.CASE_INSENSITIVE);
+        Matcher matcher = pattern.matcher(input2);
+        String output2 = matcher.replaceAll("789");
+        System.out.println(output2);
+    }
+}
diff --git a/Java/Split.java b/Java/Split.java
@@ -0,0 +1,33 @@
+import java.util.Arrays;
+import java.util.regex.Pattern;
+
+/**
+ * Example of using regular expressions for splitting strings.
+ */
+public final class Split {
+
+    /**
+     * Private constructor prevents class from being instantiated.
+     */
+    private Split() {
+
+    }
+
+    /**
+     * Entry point of the program.
+     *
+     * @param args command-line arguments, not used
+     */
+    public static void main(final String[] args) {
+        String input = "Hello World, here we are!";
+
+        //Using String API
+        String[] result1 = input.toLowerCase().split("\\W+");
+        System.out.println(Arrays.toString(result1));
+
+        // Using regex API
+        Pattern pattern = Pattern.compile("\\W+");
+        String[] result2 = pattern.split(input.toLowerCase());
+        System.out.println(Arrays.toString(result2));
+    }
+}
