如何使用PrintWriter测试方法？ [英] How to test a method using a PrintWriter?

问题描述

我有以下方法：

@Component
public class WriteCsvToResponse {

    private static final Logger LOGGER = LoggerFactory.getLogger(WriteCsvToResponse.class);

    public void writeStatus(PrintWriter writer, Status status) {

        try {

            ColumnPositionMappingStrategy mapStrategy
                = new ColumnPositionMappingStrategy();

            mapStrategy.setType(Status.class);

            String[] columns = new String[]{"id", "storeId", "status"};
            mapStrategy.setColumnMapping(columns);

            StatefulBeanToCsv btcsv = new StatefulBeanToCsvBuilder(writer)
                .withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)
                .withMappingStrategy(mapStrategy)
                .withSeparator(',')
                .build();

            btcsv.write(status);

        } catch (CsvException ex) {

            LOGGER.error("Error mapping Bean to CSV", ex);
        }
    }

我不知道如何使用 mockito 。

使用它可以将对象状态包装为 csv 格式。
我使用StringWriter将响应包装在其中。
没有更多细节了，但是看来我必须创建一些字词才能通过验证：）

Use it to wrap the object status into csv format. I used StringWriter to wrap the response in it. There are no more details left, but it seems I have to create some words to pass the validation :)

推荐答案

您不需要mockito来测试此方法，只需一个 java.io.StringWriter 。

You do not need mockito to test this method, only a java.io.StringWriter.

这里是您可以针对名义用途编写测试：

Here is how you can write the test for a nominal use:

@Test
void status_written_in_csv_format() {
    // Setup
    WriteCsvToResponse objectUnderTest = new WriteCsvToResponse ();
    StringWriter stringWriter = new StringWriter();
    PrintWriter printWriter = new PrintWriter(stringWriter);

    // Given
    Status status = ...

    // When
    objectUnderTest.writeStatus(printWriter, status);

    // Then
    String actualCsv = stringWriter.toString();
    assertThat(actualCsv.split("\n"))
       .as("Produced CSV")
       .containsExactly(
         "id,storeId,status",
         "42,142,OK");
}

此示例假设您的状态有一些事情对象，但是您有基本的想法。
对于断言，我使用 AssertJ ，但是您可以使用内置的JUnit5进行相同的操作-in断言。

This example assume some things about your Status object, but you have the general idea. For assertions, I use AssertJ, but you can do the same with JUnit5 built-in assertions.

希望这会有所帮助！

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