From 0f48c407f4e30f7a99f1321d4d28ae6d5f5fb4b9 Mon Sep 17 00:00:00 2001 From: hajarrs Date: Mon, 23 Jan 2023 14:34:39 +0100 Subject: [PATCH] Check If Command Line Arguments Are Null in Java (#13246) --- .../commandline/CommandLineWithErrorHandling.java | 12 ++++++++++++ .../commandline/CommandLineWithoutErrorHandling.java | 9 +++++++++ .../CommandLineWithoutErrorHandlingUnitTest.java | 12 ++++++++++++ 3 files changed, 33 insertions(+) create mode 100644 core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithErrorHandling.java create mode 100644 core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithoutErrorHandling.java create mode 100644 core-java-modules/core-java-lang-5/src/test/java/com/baeldung/commandline/CommandLineWithoutErrorHandlingUnitTest.java diff --git a/core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithErrorHandling.java b/core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithErrorHandling.java new file mode 100644 index 0000000000..e80a2b46d9 --- /dev/null +++ b/core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithErrorHandling.java @@ -0,0 +1,12 @@ +package com.baeldung.commandline; + +public class CommandLineWithErrorHandling { + + public static void main(String[] args) { + if (args.length > 0) { + System.out.println(args[0]); + } else { + System.out.println("No command line arguments were provided."); + } + } +} \ No newline at end of file diff --git a/core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithoutErrorHandling.java b/core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithoutErrorHandling.java new file mode 100644 index 0000000000..d761969bfd --- /dev/null +++ b/core-java-modules/core-java-lang-5/src/main/java/com/baeldung/commandline/CommandLineWithoutErrorHandling.java @@ -0,0 +1,9 @@ +package com.baeldung.commandline; + +public class CommandLineWithoutErrorHandling { + + public static void main(String[] args) { + + System.out.println(args[0]); + } +} \ No newline at end of file diff --git a/core-java-modules/core-java-lang-5/src/test/java/com/baeldung/commandline/CommandLineWithoutErrorHandlingUnitTest.java b/core-java-modules/core-java-lang-5/src/test/java/com/baeldung/commandline/CommandLineWithoutErrorHandlingUnitTest.java new file mode 100644 index 0000000000..197818631b --- /dev/null +++ b/core-java-modules/core-java-lang-5/src/test/java/com/baeldung/commandline/CommandLineWithoutErrorHandlingUnitTest.java @@ -0,0 +1,12 @@ +package com.baeldung.commandline; + +import org.junit.Test; +import static org.junit.Assert.fail; + +public class CommandLineWithoutErrorHandlingUnitTest { + + @Test(expected = NullPointerException.class) + public void givenNullCommandLineArgument_whenPassedToMainFunction_thenExpectNullPointerException() { + CommandLineWithoutErrorHandling.main(null); + } +} \ No newline at end of file