diff --git a/core-java/pom.xml b/core-java/pom.xml index e8548600f8..9c5a17d25c 100644 --- a/core-java/pom.xml +++ b/core-java/pom.xml @@ -216,8 +216,7 @@ true - + org.baeldung.executable.ExecutableMavenJar @@ -272,7 +271,7 @@ -Xmx300m -XX:+UseParallelGC -classpath - + com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed @@ -338,7 +337,7 @@ java -classpath - + org.openjdk.jmh.Main .* @@ -371,8 +370,7 @@ true - ${project.build.outputDirectory}/META-INF/MANIFEST.MF - + ${project.build.outputDirectory}/META-INF/MANIFEST.MF @@ -406,14 +404,12 @@ true - ${project.build.outputDirectory}/META-INF/MANIFEST.MF - + ${project.build.outputDirectory}/META-INF/MANIFEST.MF com/baeldung/instrumentation/application/MyAtm.class - com/baeldung/instrumentation/application/MyAtmApplication.class - + com/baeldung/instrumentation/application/MyAtmApplication.class com/baeldung/instrumentation/application/Launcher.class @@ -443,14 +439,12 @@ true - ${project.build.outputDirectory}/META-INF/MANIFEST.MF - + ${project.build.outputDirectory}/META-INF/MANIFEST.MF com/baeldung/instrumentation/agent/AtmTransformer.class - com/baeldung/instrumentation/agent/MyInstrumentationAgent.class - + com/baeldung/instrumentation/agent/MyInstrumentationAgent.class @@ -462,7 +456,6 @@ - 2.8.2 @@ -483,12 +476,10 @@ 2.21.0 - 1.1 1.4.197 2.1.0.1 1.19 - 1.19 3.0.0-M1 3.0.2 @@ -499,7 +490,6 @@ 61.1 3.21.0-GA - 1.8.0 16.0.2 diff --git a/core-java/src/main/java/com/baeldung/nulls/APIContracts.java b/core-java/src/main/java/com/baeldung/nulls/APIContracts.java index f8dfba25dd..7d6abf53b8 100644 --- a/core-java/src/main/java/com/baeldung/nulls/APIContracts.java +++ b/core-java/src/main/java/com/baeldung/nulls/APIContracts.java @@ -4,6 +4,7 @@ public class APIContracts { /** * Prints the value of {@code param} if not null. Prints {@code null} otherwise. + * * @param param */ public void print(Object param) { @@ -11,16 +12,16 @@ public class APIContracts { } /** - * * @return non null result * @throws Exception - if result is null */ public Object process() throws Exception { Object result = doSomething(); - if (result == null) + if (result == null) { throw new Exception("Processing fail. Got a null response"); - else + } else { return result; + } } private Object doSomething() { diff --git a/core-java/src/main/java/com/baeldung/nulls/Preconditions.java b/core-java/src/main/java/com/baeldung/nulls/Preconditions.java index ff32db46dd..447026f1e3 100644 --- a/core-java/src/main/java/com/baeldung/nulls/Preconditions.java +++ b/core-java/src/main/java/com/baeldung/nulls/Preconditions.java @@ -3,22 +3,26 @@ package com.baeldung.nulls; public class Preconditions { public void goodAccept(String one, String two, String three) { - if (null == one || null == two || three == null) + if (one == null || two == null || three == null) throw new IllegalArgumentException(); + + process(one); + process(two); + process(three); } - public void badAccept(String one, String two, String three){ - if (null == one) + public void badAccept(String one, String two, String three) { + if (one == null) throw new IllegalArgumentException(); else process(one); - if (null == two) + if (two == null) throw new IllegalArgumentException(); else process(two); - if (null == three) + if (three == null) throw new IllegalArgumentException(); else process(three); @@ -28,5 +32,4 @@ public class Preconditions { private void process(String one) { } - } diff --git a/core-java/src/main/java/com/baeldung/nulls/PrimitivesAndWrapper.java b/core-java/src/main/java/com/baeldung/nulls/PrimitivesAndWrapper.java index dce7a05308..8f662b3760 100644 --- a/core-java/src/main/java/com/baeldung/nulls/PrimitivesAndWrapper.java +++ b/core-java/src/main/java/com/baeldung/nulls/PrimitivesAndWrapper.java @@ -2,11 +2,11 @@ package com.baeldung.nulls; public class PrimitivesAndWrapper { - public static int sum(int a, int b) { + public static int primitiveSum(int a, int b) { return a + b; } - public static Integer sum(Integer a, Integer b) { + public static Integer wrapperSum(Integer a, Integer b) { return a + b; } @@ -17,8 +17,4 @@ public class PrimitivesAndWrapper { throw new IllegalArgumentException(); } - public static void main(String[] args) { - sum(0, 0); - sum(null, null); - } } diff --git a/core-java/src/main/java/com/baeldung/nulls/UsingObjects.java b/core-java/src/main/java/com/baeldung/nulls/UsingObjects.java index e8a3262ce7..7383ae84a7 100644 --- a/core-java/src/main/java/com/baeldung/nulls/UsingObjects.java +++ b/core-java/src/main/java/com/baeldung/nulls/UsingObjects.java @@ -4,21 +4,13 @@ import java.util.Objects; public class UsingObjects { - private String checked; - - public void accept(Object param) { + public void accept(Object param) throws Exception { try { Objects.requireNonNull(param); } catch (NullPointerException e) { - //doSomethingElseToo - e.printStackTrace(); - } - } - - public void caller() throws Exception { - if (Objects.nonNull(checked)) - accept(checked); - else throw new Exception(); + } + + //doSomething() } } diff --git a/core-java/src/main/java/com/baeldung/nulls/UsingOptional.java b/core-java/src/main/java/com/baeldung/nulls/UsingOptional.java index 626afc311d..6c17290a72 100644 --- a/core-java/src/main/java/com/baeldung/nulls/UsingOptional.java +++ b/core-java/src/main/java/com/baeldung/nulls/UsingOptional.java @@ -4,20 +4,24 @@ import java.util.Optional; public class UsingOptional { - public Optional process() { - if (isProcessed()) - return Optional.of("dummy"); - else + public Optional process(boolean processed) { + + String response = doSomething(processed); + + if (response == null) { return Optional.empty(); + } + + return Optional.of(response); } - public void caller() { - Optional result = process(); - result.ifPresent(p -> System.out.println(p)); - result.orElseThrow(() -> new IllegalArgumentException()); + private String doSomething(boolean processed) { + + if (processed) { + return "passed"; + } else { + return null; + } } - private boolean isProcessed() { - return false; - } } diff --git a/core-java/src/main/java/com/baeldung/nulls/UsingStringUtils.java b/core-java/src/main/java/com/baeldung/nulls/UsingStringUtils.java index 8cbf3752e1..c7c73b73eb 100644 --- a/core-java/src/main/java/com/baeldung/nulls/UsingStringUtils.java +++ b/core-java/src/main/java/com/baeldung/nulls/UsingStringUtils.java @@ -1,17 +1,22 @@ package com.baeldung.nulls; - import org.apache.commons.lang3.StringUtils; public class UsingStringUtils { public void accept(String param) { - if (StringUtils.isNotEmpty(param)) + if (StringUtils.isNotEmpty(param)) { System.out.println(param); + } else { + throw new IllegalArgumentException(); + } } public void acceptOnlyNonBlank(String param) { - if (StringUtils.isNotBlank(param)) + if (StringUtils.isNotBlank(param)) { System.out.println(param); + } else { + throw new IllegalArgumentException(); + } } } diff --git a/core-java/src/test/java/com/baeldung/nulls/PrimitivesAndWrapperTest.java b/core-java/src/test/java/com/baeldung/nulls/PrimitivesAndWrapperTest.java new file mode 100644 index 0000000000..4e0f44e555 --- /dev/null +++ b/core-java/src/test/java/com/baeldung/nulls/PrimitivesAndWrapperTest.java @@ -0,0 +1,35 @@ +package com.baeldung.nulls; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertThrows; + +import org.junit.jupiter.api.Test; + +class PrimitivesAndWrapperTest { + + @Test + public void givenWrappers_whenBothArgsNonNull_thenReturnResult() { + + Integer sum = PrimitivesAndWrapper.wrapperSum(0, 0); + + assertEquals(0, sum.intValue()); + } + + @Test() + public void givenWrappers_whenOneArgIsNull_thenThrowNullPointerException() { + assertThrows(NullPointerException.class, () -> PrimitivesAndWrapper.wrapperSum(null, 2)); + } + + @Test() + public void givenWrappers_whenBothArgsAreNull_thenThrowNullPointerException() { + assertThrows(NullPointerException.class, () -> PrimitivesAndWrapper.wrapperSum(null, null)); + } + + @Test() + public void givenWrappersWithNullCheck_whenAnyArgIsNull_thenThrowIllegalArgumentException() { + assertThrows(IllegalArgumentException.class, () -> PrimitivesAndWrapper.goodSum(null, 2)); + } + + + +} \ No newline at end of file diff --git a/core-java/src/test/java/com/baeldung/nulls/UsingLombokTest.java b/core-java/src/test/java/com/baeldung/nulls/UsingLombokTest.java new file mode 100644 index 0000000000..5a41d444a4 --- /dev/null +++ b/core-java/src/test/java/com/baeldung/nulls/UsingLombokTest.java @@ -0,0 +1,25 @@ +package com.baeldung.nulls; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.*; + +class UsingLombokTest { + + private UsingLombok classUnderTest; + + @BeforeEach + public void setup() { + classUnderTest = new UsingLombok(); + } + + @Test + public void whenNullArg_thenThrowNullPointerException() { + + assertThrows(NullPointerException.class, () -> classUnderTest.accept(null)); + + } + +} \ No newline at end of file diff --git a/core-java/src/test/java/com/baeldung/nulls/UsingObjectsTest.java b/core-java/src/test/java/com/baeldung/nulls/UsingObjectsTest.java new file mode 100644 index 0000000000..74170d980b --- /dev/null +++ b/core-java/src/test/java/com/baeldung/nulls/UsingObjectsTest.java @@ -0,0 +1,31 @@ +package com.baeldung.nulls; + +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; +import static org.junit.jupiter.api.Assertions.assertThrows; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +class UsingObjectsTest { + + private UsingObjects classUnderTest; + + @BeforeEach + public void setup() { + classUnderTest = new UsingObjects(); + } + + @Test + public void whenArgIsNull_thenThrowException() { + + assertThrows(Exception.class, () -> classUnderTest.accept(null)); + } + + @Test + public void whenArgIsNonNull_thenDoesNotThrowException() { + + assertDoesNotThrow(() -> classUnderTest.accept("test ")); + } + +} \ No newline at end of file diff --git a/core-java/src/test/java/com/baeldung/nulls/UsingOptionalTest.java b/core-java/src/test/java/com/baeldung/nulls/UsingOptionalTest.java new file mode 100644 index 0000000000..5c42b9dff1 --- /dev/null +++ b/core-java/src/test/java/com/baeldung/nulls/UsingOptionalTest.java @@ -0,0 +1,37 @@ +package com.baeldung.nulls; + +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertThrows; +import static org.junit.jupiter.api.Assertions.assertTrue; + +import java.util.Optional; + +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +class UsingOptionalTest { + + private UsingOptional classUnderTest; + + @BeforeEach + public void setup() { + classUnderTest = new UsingOptional(); + } + + @Test + public void whenArgIsFalse_thenReturnEmptyResponse() { + Optional result = classUnderTest.process(false); + assertFalse(result.isPresent()); + } + + @Test + public void whenArgIsTrue_thenReturnValidResponse() { + Optional result = classUnderTest.process(true); + assertTrue(result.isPresent()); + } + + @Test + public void whenArgIsFalse_thenChainResponseAndThrowException() { + assertThrows(Exception.class, () -> classUnderTest.process(false).orElseThrow(() -> new Exception())); + } +} \ No newline at end of file diff --git a/core-java/src/test/java/com/baeldung/nulls/UsingStringUtilsTest.java b/core-java/src/test/java/com/baeldung/nulls/UsingStringUtilsTest.java new file mode 100644 index 0000000000..d10364b85e --- /dev/null +++ b/core-java/src/test/java/com/baeldung/nulls/UsingStringUtilsTest.java @@ -0,0 +1,43 @@ +package com.baeldung.nulls; + +import org.junit.jupiter.api.Assertions; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.*; + +class UsingStringUtilsTest { + + private UsingStringUtils classUnderTest; + + @BeforeEach + public void setup() { + classUnderTest = new UsingStringUtils(); + } + + @Test + public void givenAccept_whenArgIsNull_throwIllegalArgumentException() { + Assertions.assertThrows(IllegalArgumentException.class, () -> classUnderTest.accept(null)); + } + + @Test + public void givenAccept_whenArgIsEmpty_throwIllegalArgumentException() { + Assertions.assertThrows(IllegalArgumentException.class, () -> classUnderTest.accept("")); + } + + @Test + public void givenAcceptOnlyNonBlank_whenArgIsNull_throwIllegalArgumentException() { + Assertions.assertThrows(IllegalArgumentException.class, () -> classUnderTest.acceptOnlyNonBlank(null)); + } + + @Test + public void givenAcceptOnlyNonBlank_whenArgIsEmpty_throwIllegalArgumentException() { + Assertions.assertThrows(IllegalArgumentException.class, () -> classUnderTest.acceptOnlyNonBlank("")); + } + + @Test + public void givenAcceptOnlyNonBlank_whenArgIsBlank_throwIllegalArgumentException() { + Assertions.assertThrows(IllegalArgumentException.class, () -> classUnderTest.acceptOnlyNonBlank(" ")); + } + +} \ No newline at end of file