Junit5:ClassNotFoundException：org.junit.platform.launcher.core.launcherFactory

Question

我正在尝试运行基本的JUnit5程序。使用Eclipse Oxygen.3a(4.7.3a)和OpenJDK9。获取以下错误-

java.lang.NoClassDefFoundError: org/junit/platform/launcher/core/LauncherFactory
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.<init>(JUnit5TestLoader.java:31)
.
.
.
Caused by: java.lang.ClassNotFoundException: org.junit.platform.launcher.core.LauncherFactory
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)

package io.javabrains;
public class MathUtils {
    public int add(int a, int b) { return a + b;}
}

package io.javabrains;
import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;
class MathUtilsTest {
    @Test
    void test() {
        System.out.println("This test ran successfully");
        //fail("Not yet implemented");
    }
}

POM

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>io.javabrains</groupId>
  <artifactId>junit-5-basics</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>junit-5-basics</name>


  <properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <junit.jupiter.version>5.4.0</junit.jupiter.version>
  </properties>

   <dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.jupiter.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.jupiter.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

Answer 1

Eclipse和JUnit有时会在移动版本中发生冲突

• 要修复您的示例，请将JUnit 5添加到Eclipse中的类路径
• Maven将运行并传递，因为它不使用缺少的启动器
• Eclipse需要具有启动器的子库
• 注意：最好将丢失的库添加到pom中，因为这个问题在跨IDE项目中仍然存在（不是每个人都使用eclipse)