JAVA-49997

core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/hashcode/application/ApplicationUnitTest.java

@@ -1,12 +1,15 @@
 package com.baeldung.hashcode.application;
 
 import com.baeldung.hashcode.standard.User;
+
 import org.junit.Test;
 
 import java.util.HashMap;
 import java.util.Map;
 
 import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 public class ApplicationUnitTest {
 
@@ -23,4 +26,14 @@ public void main_NoInputState_TextPrintedToConsole() throws Exception {
 
         assertTrue(users.containsKey(user1));
     }
+
+    @Test
+    public void givenOverriddenHashCode_whenUsingIdentityHashCode_thenJvmIdentityIsPreserved() {
+        User user1 = new User(1L, "John", "[email protected]");
+        User user2 = new User(1L, "John", "[email protected]");
+
+        assertEquals(user1.hashCode(), user2.hashCode());
+
+        assertNotEquals(System.identityHashCode(user1), System.identityHashCode(user2));
+    }
 }

core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/stringformat/StringFormatUnitTest.java

@@ -7,7 +7,6 @@
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
 import java.util.FormatFlagsConversionMismatchException;
-import java.util.IllegalFormatException;
 import java.util.IllegalFormatPrecisionException;
 import java.util.Locale;
 import java.util.MissingFormatArgumentException;
@@ -74,6 +73,12 @@ public void whenMissingFormatArgument_thenMissingFormatArgumentExceptionThrown()
         });
     }
 
+    @Test
+    public void givenAnInteger_whenPaddingWithZeros_thanIntegerGetsPadded() {
+        assertEquals("00000001", padIntegerWithZeros(1, 8));
+        assertEquals("-0000001", padIntegerWithZeros(-1, 8));
+    }
+
     @Test
     public void whenNumberFormatWithLocales_thenCorrect() {
         String frenchFormatted = String.format(Locale.FRANCE, "%,f", 1234567.89);
@@ -103,4 +108,9 @@ public void whenCurrencyFormatWithLocales_thenCorrect() {
         String frenchFormatted = frenchCurrencyFormat.format(1000);
         assertEquals("1 000,00 €", frenchFormatted);
     }
+
+    private String padIntegerWithZeros(int number, int width) {
+        return String.format("%0" + width + "d", number);
+    }
+
 }