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| 1 | +package com.baeldung.emptiness; |
| 2 | + |
| 3 | +import org.junit.Test; |
| 4 | + |
| 5 | +import java.io.File; |
| 6 | +import java.io.IOException; |
| 7 | +import java.nio.file.DirectoryStream; |
| 8 | +import java.nio.file.Files; |
| 9 | +import java.nio.file.Path; |
| 10 | +import java.nio.file.Paths; |
| 11 | +import java.util.stream.Stream; |
| 12 | + |
| 13 | +import static org.assertj.core.api.Assertions.assertThat; |
| 14 | + |
| 15 | +public class DirectoryEmptinessUnitTest { |
| 16 | + |
| 17 | + @Test |
| 18 | + public void givenPath_whenInvalid_thenReturnsFalse() throws IOException { |
| 19 | + assertThat(isEmpty(Paths.get("invalid-addr"))).isFalse(); |
| 20 | + } |
| 21 | + |
| 22 | + @Test |
| 23 | + public void givenPath_whenNotDirectory_thenReturnsFalse() throws IOException { |
| 24 | + Path aFile = Paths.get(getClass().getResource("/notDir.txt").getPath()); |
| 25 | + assertThat(isEmpty(aFile)).isFalse(); |
| 26 | + } |
| 27 | + |
| 28 | + @Test |
| 29 | + public void givenPath_whenNotEmptyDir_thenReturnsFalse() throws IOException { |
| 30 | + Path currentDir = new File("").toPath().toAbsolutePath(); |
| 31 | + assertThat(isEmpty(currentDir)).isFalse(); |
| 32 | + } |
| 33 | + |
| 34 | + @Test |
| 35 | + public void givenPath_whenIsEmpty_thenReturnsTrue() throws Exception { |
| 36 | + Path path = Files.createTempDirectory("baeldung-empty"); |
| 37 | + assertThat(isEmpty(path)).isTrue(); |
| 38 | + } |
| 39 | + |
| 40 | + private static boolean isEmpty(Path path) throws IOException { |
| 41 | + if (Files.isDirectory(path)) { |
| 42 | + try (DirectoryStream<Path> directory = Files.newDirectoryStream(path)) { |
| 43 | + return !directory.iterator().hasNext(); |
| 44 | + } |
| 45 | + } |
| 46 | + |
| 47 | + return false; |
| 48 | + } |
| 49 | + |
| 50 | + private static boolean isEmpty2(Path path) throws IOException { |
| 51 | + if (Files.isDirectory(path)) { |
| 52 | + try (Stream<Path> entries = Files.list(path)) { |
| 53 | + return !entries.findFirst().isPresent(); |
| 54 | + } |
| 55 | + } |
| 56 | + |
| 57 | + return false; |
| 58 | + } |
| 59 | + |
| 60 | + private static boolean isEmptyInefficient(Path path) { |
| 61 | + return path.toFile().listFiles().length == 0; |
| 62 | + } |
| 63 | +} |
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