BAEL-5149 (#11241)

* Init

* Removing mvnw files

* Apply eclipse code format

* Refactoring

* Refactoring

* BAEL-4211 Add benchmarks

* Delete hexagonal directory

* Refactoring based on the feedback

* Refactoring based on feedback - package rename

* Directory rename

* BAEL-5149 Remove accents from String in Java

* BAEL-5149 Remove accents from String in Java

* Including suggestions after a review

Co-authored-by: asia <joannakrzeklubowiecka@protonmail.com>

core-java-modules/core-java-string-operations-3/src/main/java/com/baeldung/accentsanddiacriticsremoval/StringNormalizer.java

@@ -0,0 +1,49 @@
+package com.baeldung.accentsanddiacriticsremoval;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.text.Normalizer;
+import java.util.StringJoiner;
+
+class StringNormalizer {
+
+    static String removeAccentsWithApacheCommons(String input) {
+        return StringUtils.stripAccents(input);
+    }
+
+    static String removeAccents(String input) {
+        return normalize(input).replaceAll("\\p{M}", "");
+    }
+
+    static String unicodeValueOfNormalizedString(String input) {
+        return toUnicode(normalize(input));
+    }
+
+    private static String normalize(String input) {
+        return input == null ? null : Normalizer.normalize(input, Normalizer.Form.NFKD);
+    }
+
+    private static String toUnicode(String input) {
+        if (input.length() == 1) {
+            return toUnicode(input.charAt(0));
+        } else {
+            StringJoiner stringJoiner = new StringJoiner(" ");
+            for (char c : input.toCharArray()) {
+                stringJoiner.add(toUnicode(c));
+            }
+            return stringJoiner.toString();
+        }
+    }
+
+    private static String toUnicode(char input) {
+
+        String hex = Integer.toHexString(input);
+        StringBuilder sb = new StringBuilder(hex);
+
+        while (sb.length() < 4) {
+            sb.insert(0, "0");
+        }
+        sb.insert(0, "\\u");
+        return sb.toString();
+    }
+}

core-java-modules/core-java-string-operations-3/src/test/java/com/baeldung/accentsanddiacriticsremoval/CollatorUnitTest.java

@@ -0,0 +1,70 @@
+package com.baeldung.accentsanddiacriticsremoval;
+
+import org.junit.Test;
+import org.openjdk.jmh.annotations.Setup;
+
+import java.text.Collator;
+
+import static java.lang.Character.*;
+import static java.lang.String.valueOf;
+import static org.junit.Assert.assertEquals;
+
+public class CollatorUnitTest {
+
+    private final Collator collator = Collator.getInstance();
+
+    @Setup
+    public void setup() {
+        collator.setDecomposition(2);
+    }
+
+    @Test
+    public void givenAccentedStringAndPrimaryCollatorStrength_whenCompareWithASCIIString_thenReturnTrue() {
+        Collator collator = Collator.getInstance();
+        collator.setDecomposition(2);
+        collator.setStrength(0);
+        assertEquals(0, collator.compare("a", "a"));
+        assertEquals(0, collator.compare("ä", "a"));
+        assertEquals(0, collator.compare("A", "a"));
+        assertEquals(1, collator.compare("b", "a"));
+        assertEquals(0, collator.compare(valueOf(toChars(0x0001)), valueOf(toChars(0x0002))));
+    }
+
+    @Test
+    public void givenAccentedStringAndSecondaryCollatorStrength_whenCompareWithASCIIString_thenReturnTrue() {
+        collator.setStrength(1);
+        assertEquals(1, collator.compare("ä", "a"));
+        assertEquals(1, collator.compare("b", "a"));
+        assertEquals(0, collator.compare("A", "a"));
+        assertEquals(0, collator.compare("a", "a"));
+        assertEquals(0, collator.compare(valueOf(toChars(0x0001)), valueOf(toChars(0x0002))));
+
+    }
+
+    @Test
+    public void givenAccentedStringAndTeriaryCollatorStrength_whenCompareWithASCIIString_thenReturnTrue() {
+        collator.setStrength(2);
+        assertEquals(1, collator.compare("A", "a"));
+        assertEquals(1, collator.compare("ä", "a"));
+        assertEquals(1, collator.compare("b", "a"));
+        assertEquals(0, collator.compare("a", "a"));
+        assertEquals(0, collator.compare(valueOf(toChars(0x0001)), valueOf(toChars(0x0002))));
+    }
+
+    @Test
+    public void givenAccentedStringAndIdenticalCollatorStrength_whenCompareWithASCIIString_thenReturnTrue() {
+        collator.setStrength(3);
+        assertEquals(1, collator.compare("A", "a"));
+        assertEquals(1, collator.compare("ä", "a"));
+        assertEquals(1, collator.compare("b", "a"));
+        assertEquals(-1, collator.compare(valueOf(toChars(0x0001)), valueOf(toChars(0x0002))));
+        assertEquals(0, collator.compare("a", "a"));
+    }
+
+    @Test
+    public void givenNondecomposableAccentedStringAndIdenticalCollatorStrength_whenCompareWithASCIIString_thenReturnTrue() {
+        collator.setStrength(0);
+        assertEquals(1, collator.compare("ł", "l"));
+        assertEquals(1, collator.compare("ø", "o"));
+    }
+}

core-java-modules/core-java-string-operations-3/src/test/java/com/baeldung/accentsanddiacriticsremoval/StringNormalizerUnitTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.accentsanddiacriticsremoval;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.text.Normalizer;
+
+import org.junit.jupiter.api.Test;
+
+class StringNormalizerUnitTest {
+
+    @Test
+    public void givenNotNormalizedString_whenIsNormalized_thenReturnFalse() {
+        assertFalse(Normalizer.isNormalized("āăąēîïĩíĝġńñšŝśûůŷ", Normalizer.Form.NFKD));
+    }
+
+    @Test
+    void givenStringWithDecomposableUnicodeCharacters_whenRemoveAccents_thenReturnASCIIString() {
+        assertEquals("aaaeiiiiggnnsssuuy", StringNormalizer.removeAccents("āăąēîïĩíĝġńñšŝśûůŷ"));
+    }
+
+    @Test
+    void givenStringWithDecomposableUnicodeCharacters_whenRemoveAccentsWithApacheCommons_thenReturnASCIIString() {
+        assertEquals("aaaeiiiiggnnsssuuy", StringNormalizer.removeAccentsWithApacheCommons("āăąēîïĩíĝġńñšŝśûůŷ"));
+    }
+
+    @Test
+    void givenStringWithNondecomposableUnicodeCharacters_whenRemoveAccents_thenReturnOriginalString() {
+        assertEquals("łđħœ", StringNormalizer.removeAccents("łđħœ"));
+    }
+
+    @Test
+    void givenStringWithNondecomposableUnicodeCharacters_whenRemoveAccentsWithApacheCommons_thenReturnModifiedString() {
+        assertEquals("lđħœ", StringNormalizer.removeAccentsWithApacheCommons("łđħœ"));
+    }
+
+    @Test
+    void givenStringWithDecomposableUnicodeCharacters_whenUnicodeValueOfNormalizedString_thenReturnUnicodeValue() {
+        assertEquals("\\u0066 \\u0069", StringNormalizer.unicodeValueOfNormalizedString("fi"));
+        assertEquals("\\u0061 \\u0304", StringNormalizer.unicodeValueOfNormalizedString("ā"));
+        assertEquals("\\u0069 \\u0308", StringNormalizer.unicodeValueOfNormalizedString("ï"));
+        assertEquals("\\u006e \\u0301", StringNormalizer.unicodeValueOfNormalizedString("ń"));
+    }
+
+    @Test
+    void givenStringWithNonDecomposableUnicodeCharacters_whenUnicodeValueOfNormalizedString_thenReturnOriginalValue() {
+        assertEquals("\\u0142", StringNormalizer.unicodeValueOfNormalizedString("ł"));
+        assertEquals("\\u0127", StringNormalizer.unicodeValueOfNormalizedString("ħ"));
+        assertEquals("\\u0111", StringNormalizer.unicodeValueOfNormalizedString("đ"));
+    }
+}