如何让JUnit5指定测试类按顺序执行，其余测试并行？

1. 拆分Surefire执行阶段，混合串行与并行 #

通过配置Surefire的多执行阶段，先串行跑指定的两个测试类，再并行执行其余测试，完美匹配你的需求：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>3.2.5</version>
    <executions>
        <!-- 第一阶段：串行执行需要顺序的测试类 -->
        <execution>
            <id>run-sequential-tests</id>
            <phase>test</phase>
            <goals>
                <goal>test</goal>
            </goals>
            <configuration>
                <includes>
                    <include>**/TestClassA.java</include>
                    <include>**/TestClassB.java</include>
                </includes>
                <parallel>none</parallel>
                <forkCount>1</forkCount>
            </configuration>
        </execution>
        <!-- 第二阶段：并行执行剩余所有测试 -->
        <execution>
            <id>run-parallel-tests</id>
            <phase>test</phase>
            <goals>
                <goal>test</goal>
            </goals>
            <configuration>
                <excludes>
                    <exclude>**/TestClassA.java</exclude>
                    <exclude>**/TestClassB.java</exclude>
                </excludes>
                <parallel>classes</parallel>
                <forkCount>4</forkCount> <!-- 可根据CPU核心数调整 -->
                <reuseForks>true</reuseForks>
            </configuration>
        </execution>
    </executions>
</plugin>

2. 用测试套件控制顺序，配合并行配置 #

创建一个测试套件指定两个类的执行顺序，再让Surefire分开执行套件和其余并行测试：

• 编写JUnit 5测试套件：

import org.junit.platform.suite.api.SelectClasses;
import org.junit.platform.suite.api.Suite;

@Suite
@SelectClasses({TestClassA.class, TestClassB.class})
public class SequentialTestSuite {
}

• 对应Surefire配置：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>3.2.5</version>
    <executions>
        <execution>
            <id>run-sequential-suite</id>
            <phase>test</phase>
            <goals>
                <goal>test</goal>
            </goals>
            <configuration>
                <includes>
                    <include>**/SequentialTestSuite.java</include>
                </includes>
                <parallel>none</parallel>
            </configuration>
        </execution>
        <execution>
            <id>run-parallel-tests</id>
            <phase>test</phase>
            <goals>
                <goal>test</goal>
            </goals>
            <configuration>
                <excludes>
                    <exclude>**/SequentialTestSuite.java</exclude>
                    <exclude>**/TestClassA.java</exclude>
                    <exclude>**/TestClassB.java</exclude>
                </excludes>
                <parallel>classes</parallel>
                <forkCount>4</forkCount>
            </configuration>
        </execution>
    </executions>
</plugin>

如果用JUnit 4，套件换成@RunWith(Suite.class)和@SuiteClasses注解即可。

3. 排查批量失败的核心原因 #

批量跑失败但单个执行正常，90%是测试间状态污染：

• 检查两个测试类是否依赖同一静态变量、数据库连接、文件资源等共享数据
• 在@AfterEach/@AfterAll方法中强制重置资源，比如清空静态缓存、关闭数据库连接池
• 可给这两个类加@Isolated注解（JUnit 5），让Surefire为它们单独分配进程，彻底隔离环境

内容的提问来源于stack exchange，提问作者user19128690