BAEL-5642 Using @NotNull as a method parameter (#12483)

* BAEL-5642 Using @NotNull as a method parameter

* BAEL-5642 Add Spring Boot and bump spring and hibernate-validator versions

javaxval/pom.xml

@@ -34,6 +34,17 @@
             <artifactId>spring-test</artifactId>
             <version>${org.springframework.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+            <version>${spring.boot.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <version>${spring.boot.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 		
     <!-- uncomment in order to enable Hibernate Validator Anotation Processor -->
@@ -46,13 +57,14 @@
         </plugin> </plugins> </build> -->
 
     <properties>
-        <hibernate-validator.version>6.0.13.Final</hibernate-validator.version>
+        <hibernate-validator.version>6.2.3.Final</hibernate-validator.version>
         <hibernate-validator.ap.version>6.2.0.Final</hibernate-validator.ap.version>
         <maven.compiler.version>3.6.1</maven.compiler.version>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
         <javax.el.version>3.0.0</javax.el.version>
-        <org.springframework.version>5.0.2.RELEASE</org.springframework.version>
+        <org.springframework.version>5.3.21</org.springframework.version>
+        <spring.boot.version>2.7.1</spring.boot.version>
     </properties>
 
 </project>

javaxval/src/main/java/com/baeldung/javaxval/notnull/NotNullMethodParameter.java

@@ -0,0 +1,22 @@
+package com.baeldung.javaxval.notnull;
+
+import javax.validation.Validation;
+import javax.validation.Validator;
+import javax.validation.ValidatorFactory;
+import javax.validation.constraints.NotNull;
+
+public class NotNullMethodParameter {
+
+    ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
+    Validator validator = factory.getValidator();
+
+    public int doesNotValidateNotNull(@NotNull String myString) {
+        return myString.length();
+    }
+
+    public int validateNotNull(@NotNull String myString) {
+        validator.validate(myString);
+        return myString.length();
+    }
+
+}

javaxval/src/main/java/com/baeldung/javaxval/notnull/ValidatingComponent.java

@@ -0,0 +1,21 @@
+package com.baeldung.javaxval.notnull;
+
+import org.springframework.stereotype.Component;
+import org.springframework.validation.annotation.Validated;
+
+import javax.validation.constraints.NotNull;
+
+@Component
+@Validated
+public class ValidatingComponent {
+
+    public int validateNotNull(@NotNull String data)
+    {
+        return data.length();
+    }
+
+    public int callAnnotatedMethod(String data) {
+        return validateNotNull(data);
+    }
+
+}

javaxval/src/test/java/com/baeldung/javaxval/notnull/NotNullMethodParameterUnitTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.javaxval.notnull;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class NotNullMethodParameterUnitTest {
+
+    private NotNullMethodParameter demo = new NotNullMethodParameter();
+
+    @Test
+    public void givenNull_whenInvokedwithNoValidator_thenNullPointerException() {
+        assertThrows(NullPointerException.class, () -> demo.doesNotValidateNotNull(null));
+    }
+
+    @Test
+    public void givenNull_whenInvokedWithValidator_thenIllegalArgumentException() {
+        assertThrows(IllegalArgumentException.class, () -> demo.validateNotNull(null));
+    }
+
+}

javaxval/src/test/java/com/baeldung/javaxval/notnull/ValidatingComponentIntegrationTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.javaxval.notnull;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.ConstraintViolationException;
+import javax.validation.constraints.NotNull;
+import java.util.Set;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@SpringBootTest
+class ValidatingComponentIntegrationTest {
+
+    @Autowired ValidatingComponent component;
+
+    @Test
+    void givenValue_whenValidate_thenSuccess() {
+        assertThat(component.validateNotNull("Not null!"), is(9));
+    }
+
+    @Test
+    void givenNull_whenValidate_thenConstraintViolationException() {
+        ConstraintViolationException constraintViolationException = assertThrows(ConstraintViolationException.class, () -> component.validateNotNull(null));
+        Set<ConstraintViolation<?>> constraintViolations = constraintViolationException.getConstraintViolations();
+        assertThat(constraintViolations.iterator().next().getConstraintDescriptor().getAnnotation().annotationType(), is(NotNull.class));
+    }
+
+    @Test
+    void givenNull_whenOnlyCalledMethodHasAnnotation_thenNoValidation() {
+        assertThrows(NullPointerException.class, () -> component.callAnnotatedMethod(null));
+    }
+
+    @SpringBootApplication
+    static class TestApplication {
+    }
+
+}