java.lang.NoClassDefFoundError: org/hamcrest/Matchers

Question

我正在运行带有Maven 3的JUnit5测试用例。

现在我想在 Testcase AppTest 中使用 Java 导入中的库 hamcrest.java：

import static org.junit.jupiter.api.Assertions.*;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.lessThan;

对于使用 App.java 的测试用例 AppTest.java：

double result;
result = app.probability_a_dash(23);
System.out.println("result: "+ result);
assertEquals(lessThan(0.5d), result);

导入时的错误是：

java.lang.NoClassDefFoundError： org/hamcrest/Matchers

如何将Hamcrest库正确集成到maven构建中： 命令行上的 mvn 正确集成了 hamcrest，只有 IDE 智能 IDEA 混淆了导入！

不幸的是，JUnit5 没有检测到带有 hamcrestlessThan的0.0 < 0.5：我如何获得一个通过的测试用例？

我的pom.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<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>com.auticon.birthdays</groupId>
<artifactId>CalculateBirthdays</artifactId>
<version>1.0-SNAPSHOT</version>
<name>CalculateBirthdays</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>11</java.version>
<maven.compiler.source>${java.version}</maven.compiler.source>
<maven.compiler.target>${java.version}</maven.compiler.target>
<junit-platform.version>5.6.0</junit-platform.version>
</properties>
<dependencies>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<version>${junit-platform.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>${junit-platform.version}</version>
<scope>test</scope>
</dependency>

<dependency>
<groupId>org.hamcrest</groupId>
<artifactId>hamcrest</artifactId>
<version>2.2</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.auticon.birthdays.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
<plugin>
<artifactId>maven-site-plugin</artifactId>
<version>3.7.1</version>
</plugin>
<plugin>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>3.0.0</version>
</plugin>


<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.22.1</version>
<configuration>
<argLine>
--illegal-access=permit
</argLine>
</configuration>
</plugin>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<filesets>
<fileset>
<directory>${basedir}</directory>
<includes>
<include>**/contacts.xml</include>
<include>**/contacts (1).xml</include>
<include>**/contacts (2).xml</include>
</includes>
<excludes>
<exclude>**/important.log</exclude>
<exclude>**/another-important.log</exclude>
</excludes>
<followSymlinks>false</followSymlinks>
</fileset>
</filesets>
</configuration>
</plugin>

</plugins>
</pluginManagement>
</build>
</project>

Answer 1

我在运行我的 maven 项目时遇到了同样的错误。因此，我不得不使用hancrest-all，这是一个独立的hamcrest罐，将所有子模块包含在单个工件中。

<dependency>
<groupId>org.hamcrest</groupId>
<artifactId>hamcrest-all</artifactId>
<version>1.3</version>
<scope>test</scope>
</dependency>

检查此链接： https://mvnrepository.com/artifact/org.hamcrest/hamcrest-all/1.3

Answer 2

代替 JUnit5assertEquals，我不得不在AppTest.java使用以下hamcrest方法：

import static org.hamcrest.Matchers.*;
import static org.hamcrest.MatcherAssert.assertThat;

和

assertThat(result, lessThan(0.5d));