JUnit 5 Collection 类型参数导致“@ParameterizedTest”错误

Question

我无法从之前提出的问题中找到错误原因，因为它们与“@Test”（不允许自定义数据类型）有关。

我有一个程序，它接受一个字符串类型的输入（通常是一个文本块），并以列表的形式返回输入的句子。为了正确测试这个程序，我尝试以列表的形式存储我的输入和预期输出（将与我的程序的输出、测试的目的进行比较）。这里 DataStructure 类由 2 个属性组成：一个 String 类型属性和一个 List 类型属性。

总的来说，我有一些关于程序本身的必要类，SentenceSplitterTest 类，DataStructure 类和 Collection 类。在 Collection 类中，我处理上面提到的 List 的加载过程。我基本上做一些文件操作并将我的输入和预期输出存储在 Collection 类中。下面是我的 ProgramTest.java 文件的内容。

package Classes;

import org.junit.Before;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.MethodSource;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import static org.junit.jupiter.api.Assertions.assertEquals;

@RunWith(Parameterized.class)
public class SentenceSplitterTest  {

    private String input;
    private List<String> output = new ArrayList<>();
    private SentenceSplitter sentencesplitter;
    private static CollectionClass collectionClass;

    static {
        try {
            collectionClass = new CollectionClass();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public SentenceSplitterTest(String input, List<String> output)  {
        super();
        this.input = input;
        this.output = output;
    }

    @Before
    public void initialize() throws IOException {

        sentencesplitter = new SentenceSplitter();
    }

    @ParameterizedTest
    @MethodSource("data")
    public void testSentenceSplitterTest() {

        System.out.println("Expected output: " + output);
        assertEquals(output, sentencesplitter.sentenceSplit(input));
    }

    public static Collection data() {
        return collectionClass.getContent();
    }
}

如您所见，我使用@MethodSource("data") 来设置参数。我的测试屏幕看起来像this

我在屏幕截图中收到以下 InitializationError 错误：

java.lang.Exception：类上没有公共静态参数方法 Classes.SentenceSplitterTest

屏幕截图中的每个元素都出现以下错误：

org.junit.jupiter.api.extension.ParameterResolutionException: 否 为参数 [java.lang.String arg0] 注册的 ParameterResolver 可执行[公共 Classes.SentenceSplitterTest(java.lang.String,java.util.List)]。 我找不到我应该做些什么来解决这些问题。请帮忙。

编辑 1：我被要求分享 CollectionClass 类。

package Classes;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

import static java.nio.file.Files.readAllLines;

public class CollectionClass {

    private static List<DataStructure> collection = new ArrayList<>();

    public List<DataStructure> getContent() {
        return collection;
    }

    public CollectionClass() throws IOException {

        List<String> inputs = readAllLines(Paths.get("inputs.txt"), StandardCharsets.UTF_8);
        List<String> outputs = readAllLines(Paths.get("outputs.txt"), StandardCharsets.UTF_8);

        int i = 0;
        int j = 0;
        int ctr = 0;

        while(i< inputs.size() || j< outputs.size()) {

            DataStructure structure = new DataStructure();
            String inputIncoming = null;
            List<String> outputIncoming = new ArrayList<String>();

            if(i< inputs.size()) {

                if(!inputs.get(i).equals("-")) {
                    // nothing

                }
                else {
                    i++;
                    inputIncoming = inputs.get(i);
                   structure.string = inputIncoming;
                }
            }

            if(j< outputs.size()) {


                if(!outputs.get(j).equals("-") && !outputs.get(j).equals("--")) {
                    // nothing
                }
                else {
                    if(outputs.get(j).equals("-")) {
                        j++;
                        outputIncoming.add(outputs.get(j));
                        structure.listOfString = outputIncoming;
                    }
                    else if(outputs.get(j).equals("--")) {
                        j++;
                        outputIncoming.add(outputs.get(j));
                        j++;
                        outputIncoming.add(outputs.get(j));
                        structure.listOfString = outputIncoming;
                    }
                }
            }

            collection.add(ctr,structure);

            i++;
            j++;
            ctr++;
        }
        for(DataStructure structure: collection) {
            System.out.println(structure.string);
            System.out.println(structure.listOfString);
        }
    }
}

我也想添加 DataStructure 类。

package Classes;

import java.util.ArrayList;
import java.util.List;

public class DataStructure {

    public String string;
    public List<String> listOfString = new ArrayList<>();
}

编辑 2：我被要求放置堆栈跟踪。在这里。

java.lang.NullPointerException
    at Classes.SentenceSplitterTest.testSentenceSplitterTest(SentenceSplitterTest.java:46)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:389)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:167)
    at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:163)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:110)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:83)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$0(HierarchicalTestExecutor.java:85)
    at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:114)
    at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.lambda$execute$2(TestTemplateTestDescriptor.java:86)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$11$1.accept(ReferencePipeline.java:442)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1492)
    at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658)
    at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
    at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1492)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
    at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1492)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:86)
    at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:36)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:83)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
    at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
    at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
    at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
    at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:51)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Answer 1

您正在混合使用 JUnit 4 和 JUnit Jupiter 参数化测试。在 JUnit JUpiter 中，没有测试运行器，构造函数保持无参数，您将参数传递给测试方法（在某种程度上让人想起 JUnit 4 的理论）：

public class SentenceSplitterTest  {
    private SentenceSplitter sentencesplitter;
    private static CollectionClass collectionClass;

    // Initialization of CollectionClass moved here (instead of a static block) for two 
    // reasons:
    // 1. If the initialization fails, you can't run the test anyway - better fail 
    //    right here that print an error and continue to the test which we 
    //    know won't work
    // 2. It just looks neater
    @BeforeAll
    public static void initializeCollectionClass() throws IOException {
        collectionClass = new CollectionClass();
    }

    @BeforeEach
    public void initializeSentenceSplitter() throws IOException {
        sentencesplitter = new SentenceSplitter();
    }

    @ParameterizedTest
    @MethodSource("data")
    public void testSentenceSplitterTest(DataStructure ds) {
        String input = ds.string;
        List<String> output = ds.listOfString;
        assertEquals(output, sentencesplitter.sentenceSplit(input));
    }

    public static Stream<DataStructure> data() {
        return collectionClass.getContent().stream();
    }
}