添加理解 Java 中的 NumberFormatException 异常 的链接

core-java-modules/core-java-strings/src/test/java/com/ossez/chararraypassword/PasswordStoreExamplesUnitTest.java

@@ -67,4 +67,42 @@ public class PasswordStoreExamplesUnitTest {
     public void whenCallingToStringOfCharArray_ThenValuesNotEqual() {
         assertThat(charPassword.toString()).isNotEqualTo("password");
     }
+
+    @Test
+    public void immutableForString() {
+        String stringPassword = "password";
+        System.out.print("Original String password value: ");
+        System.out.println(stringPassword);
+        System.out.println("Original String password hashCode: " + Integer.toHexString(stringPassword.hashCode()));
+
+        String newString = "********";
+        stringPassword.replace(stringPassword, newString);
+
+        System.out.print("String password value after trying to replace it: ");
+        System.out.println(stringPassword);
+        System.out.println("hashCode after trying to replace the original String: " + Integer.toHexString(stringPassword.hashCode()));
+    }
+
+    @Test
+    public void immutableForCharArray() {
+        char[] charPassword = new char[]{'p', 'a', 's', 's', 'w', 'o', 'r', 'd'};
+
+        System.out.print("Original char password value: ");
+        System.out.println(charPassword);
+        System.out.println("Original char password hashCode: " + Integer.toHexString(charPassword.hashCode()));
+
+        Arrays.fill(charPassword, '*');
+
+        System.out.print("Changed char password value: ");
+        System.out.println(charPassword);
+        System.out.println("Changed char password hashCode: " + Integer.toHexString(charPassword.hashCode()));
+    }
+
+    @Test
+    public void accidentallyPassword_print() {
+        String passwordString = "password";
+        char[] passwordArray = new char[]{'p', 'a', 's', 's', 'w', 'o', 'r', 'd'};
+        System.out.println("Printing String password -> " + passwordString);
+        System.out.println("Printing char[] password -> " + passwordArray.toString());
+    }
 }