Junit 无法使用 Spark Structured Streaming 创建的文件删除 @TempDir

Question

我为我的管道创建了一个集成测试来检查是否生成了正确的 CSV 文件：

class CsvBatchSinkTest {

    @RegisterExtension
    static SparkExtension spark = new SparkExtension();

    @TempDir
    static Path directory;

    //this checks if the file is already available
    static boolean isFileWithSuffixAvailable(File directory, String suffix) throws IOException {
        return Files.walk(directory.toPath()).anyMatch(f -> f.toString().endsWith(suffix));
    }

    //this gets content of file
    static List<String> extractFileWithSuffixContent(File file, String suffix) throws IOException {
        return Files.readAllLines(
                Files.walk(file.toPath())
                        .filter(f -> f.toString().endsWith(suffix))
                        .findFirst()
                        .orElseThrow(AssertionException::new));
    }

    @Test
    @DisplayName("When correct dataset is sent to sink, then correct csv file should be generated.")
    void testWrite() throws IOException, InterruptedException {

        File file = new File(directory.toFile(), "output");


        List<Row> data =
                asList(RowFactory.create("value1", "value2"), RowFactory.create("value3", "value4"));

        Dataset<Row> dataset =
                spark.session().createDataFrame(data, CommonTestSchemas.SCHEMA_2_STRING_FIELDS);

         dataset.coalesce(1)
                .write()
                .option("header", "true")
                .option("delimiter", ";")
                .csv(file.getAbsolutePath());

        Awaitility.await()
                .atMost(10, TimeUnit.SECONDS)
                .until(() -> isFileWithSuffixAvailable(file, ".csv"));

        Awaitility.await()
                .atMost(10, TimeUnit.SECONDS)
                .untilAsserted(
                        () ->
                                assertThat(extractFileWithSuffixContent(file, ".csv"))
                                        .containsExactlyInAnyOrder("field1;field2", "value1;value2", "value3;value4"));
    }
}

真实代码看起来有点不同，这只是一个可重现的例子。

Spark 扩展只是在每次测试之前启动本地 spark，并在之后关闭。

测试通过，但是当 junit 尝试清理时 @TempDir 抛出以下异常：

Failed to delete temp directory C:\Users\RK03GJ\AppData\Local\Temp\junit596680345801656194. The following paths could not be deleted

我能以某种方式修复这个错误吗？我试着等待 spark 停止使用 awaility，但我并没有真正帮助。

也许我可以忽略这个错误？

Answer 1

快速猜测：您需要关闭 Files.walk 返回的流。引自文档：

If timely disposal of file system resources is required, the try-with-resources construct should be used to ensure that the stream's close method is invoked after the stream operations are completed.

-- https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#walk-java.nio.file.Path-java.nio.file.FileVisitOption...-

要解决此问题，请在 isFileWithSuffixAvailable 方法中添加一个 try-with-resources：

static boolean isFileWithSuffixAvailable(File directory, String suffix) throws IOException {
    try (Stream<Path> walk = Files.walk(directory.toPath())) {
        return walk.anyMatch(f -> f.toString().endsWith(suffix));
    }
}

Junit 无法使用 Spark Structured Streaming 创建的文件删除 @TempDir

Junit cannot delete @TempDir with file created by Spark Structured Streaming

java

junit

tempdir

temporary-directory