init commit (#11623)

core-java-modules/core-java-string-operations-4/src/main/java/com/baeldung/split/SplitStringEveryNthChar.java

@@ -0,0 +1,51 @@
+package com.baeldung.split;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.google.common.base.Splitter;
+import com.google.common.collect.ImmutableList;
+
+public class SplitStringEveryNthChar {
+
+    public static List<String> usingSplitMethod(String text, int n) {
+        String[] results = text.split("(?<=\\G.{" + n + "})");
+
+        return Arrays.asList(results);
+    }
+
+    public static List<String> usingSubstringMethod(String text, int n) {
+        List<String> results = new ArrayList<>();
+        int length = text.length();
+
+        for (int i = 0; i < length; i += n) {
+            results.add(text.substring(i, Math.min(length, i + n)));
+        }
+
+        return results;
+    }
+
+    public static List<String> usingPattern(String text, int n) {
+        List<String> results = new ArrayList<>();
+
+        Pattern pattern = Pattern.compile(".{1," + n + "}");
+        Matcher matcher = pattern.matcher(text);
+        while (matcher.find()) {
+            String match = text.substring(matcher.start(), matcher.end());
+            results.add(match);
+        }
+
+        return results;
+    }
+
+    public static List<String> usingGuava(String text, int n) {
+        Iterable<String> parts = Splitter.fixedLength(n)
+            .split(text);
+
+        return ImmutableList.copyOf(parts);
+    }
+
+}

core-java-modules/core-java-string-operations-4/src/test/java/com/baeldung/split/SplitStringEveryNthCharUnitTest.java

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+package com.baeldung.split;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.collection.IsIterableContainingInOrder.contains;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+public class SplitStringEveryNthCharUnitTest {
+
+    public static final String TEXT = "abcdefgh123456";
+
+    @Test
+    public void givenString_whenUsingSplit_thenSplit() {
+        List<String> results = SplitStringEveryNthChar.usingSplitMethod(TEXT, 3);
+
+        assertThat(results, contains("abc", "def", "gh1", "234", "56"));
+    }
+
+    @Test
+    public void givenString_whenUsingSubstring_thenSplit() {
+        List<String> results = SplitStringEveryNthChar.usingSubstringMethod(TEXT, 4);
+
+        assertThat(results, contains("abcd", "efgh", "1234", "56"));
+    }
+
+    @Test
+    public void givenString_whenUsingPattern_thenSplit() {
+        List<String> results = SplitStringEveryNthChar.usingPattern(TEXT, 5);
+
+        assertThat(results, contains("abcde", "fgh12", "3456"));
+    }
+
+    @Test
+    public void givenString_whenUsingGuava_thenSplit() {
+        List<String> results = SplitStringEveryNthChar.usingGuava(TEXT, 6);
+
+        assertThat(results, contains("abcdef", "gh1234", "56"));
+    }
+
+}