Merge pull request #10285 from sk1418/delFileExt

[BAEL-4722] remove file extensions

core-java-modules/core-java-io-3/src/main/java/com/baeldung/filenamewithoutextension/MyFilenameUtil.java

@@ -0,0 +1,14 @@
+package com.baeldung.filenamewithoutextension;
+
+public class MyFilenameUtil {
+    private MyFilenameUtil() {}
+
+    public static String removeFileExtension(String filename, boolean removeAllExtensions) {
+        if (filename == null || filename.isEmpty()) {
+            return filename;
+        }
+
+        String extPattern = "(?<!^)[.]" + (removeAllExtensions ? ".*" : "[^.]*$");
+        return filename.replaceAll(extPattern, "");
+    }
+}

core-java-modules/core-java-io-3/src/test/java/com/baeldung/filenamewithoutextension/FileNameDelExtensionUnitTest.java

@@ -0,0 +1,72 @@
+package com.baeldung.filenamewithoutextension;
+
+import com.google.common.io.Files;
+import org.apache.commons.io.FilenameUtils;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+public class FileNameDelExtensionUnitTest {
+
+    @Test
+    public void givenDotFileWithoutExt_whenCallGuavaMethod_thenCannotGetDesiredResult() {
+        //negative assertion
+        assertNotEquals(".baeldung", Files.getNameWithoutExtension(".baeldung"));
+    }
+
+    @Test
+    public void givenFileWithoutMultipleExt_whenCallGuavaMethod_thenCannotRemoveAllExtensions() {
+        //negative assertion
+        assertNotEquals("baeldung", Files.getNameWithoutExtension("baeldung.tar.gz"));
+    }
+
+    @Test
+    public void givenDotFileWithoutExt_whenCallApacheCommonsMethod_thenCannotGetDesiredResult() {
+        //negative assertion
+        assertNotEquals(".baeldung", FilenameUtils.removeExtension(".baeldung"));
+    }
+
+    @Test
+    public void givenFileWithoutMultipleExt_whenCallApacheCommonsMethod_thenCannotRemoveAllExtensions() {
+        //negative assertion
+        assertNotEquals("baeldung", FilenameUtils.removeExtension("baeldung.tar.gz"));
+    }
+
+    @Test
+    public void givenFilenameNoExt_whenCallFilenameUtilMethod_thenGetExpectedFilename() {
+        assertEquals("baeldung", MyFilenameUtil.removeFileExtension("baeldung", true));
+        assertEquals("baeldung", MyFilenameUtil.removeFileExtension("baeldung", false));
+    }
+
+    @Test
+    public void givenSingleExt_whenCallFilenameUtilMethod_thenGetExpectedFilename() {
+        assertEquals("baeldung", MyFilenameUtil.removeFileExtension("baeldung.txt", true));
+        assertEquals("baeldung", MyFilenameUtil.removeFileExtension("baeldung.txt", false));
+    }
+
+
+    @Test
+    public void givenDotFile_whenCallFilenameUtilMethod_thenGetExpectedFilename() {
+        assertEquals(".baeldung", MyFilenameUtil.removeFileExtension(".baeldung", true));
+        assertEquals(".baeldung", MyFilenameUtil.removeFileExtension(".baeldung", false));
+    }
+
+    @Test
+    public void givenDotFileWithExt_whenCallFilenameUtilMethod_thenGetExpectedFilename() {
+        assertEquals(".baeldung", MyFilenameUtil.removeFileExtension(".baeldung.conf", true));
+        assertEquals(".baeldung", MyFilenameUtil.removeFileExtension(".baeldung.conf", false));
+    }
+
+    @Test
+    public void givenDoubleExt_whenCallFilenameUtilMethod_thenGetExpectedFilename() {
+        assertEquals("baeldung", MyFilenameUtil.removeFileExtension("baeldung.tar.gz", true));
+        assertEquals("baeldung.tar", MyFilenameUtil.removeFileExtension("baeldung.tar.gz", false));
+    }
+
+    @Test
+    public void givenDotFileWithDoubleExt_whenCallFilenameUtilMethod_thenGetExpectedFilename() {
+        assertEquals(".baeldung", MyFilenameUtil.removeFileExtension(".baeldung.conf.bak", true));
+        assertEquals(".baeldung.conf", MyFilenameUtil.removeFileExtension(".baeldung.conf.bak", false));
+    }
+}