Maven执行JUnit4测试套件时无限挂起问题求助

问题概述 #

旧项目Maven化改造后，执行mvn test时，caffeine-tests项目的测试套件在运行首个测试时无限挂起，远程Java进程未崩溃但持续等待；直接用JUnit4运行所有测试完全正常。调试确认测试用例已全部加入套件，挂起发生在CaffeineLauncher(TestCase).runBare()栈帧，之后该栈帧被清除。已尝试清理项目、更新Maven项目，问题未解决。

关键信息 #

远程调试日志 #

C:\Users\***\Caffeine Tests\src\main\resources>mvnDebug -DforkCount=0 test
Listening for transport dt_socket at address: 8000
[INFO] Scanning for projects...
[INFO]
[INFO] -------------------< caffeine-tests:caffeine-tests >--------------------
[INFO] Building caffeine-tests 0.0.1-SNAPSHOT
[INFO]   from pom.xml
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- resources:3.3.1:resources (default-resources) @ caffeine-tests ---
[INFO] skip non existing resourceDirectory C:\Users\***\Caffeine Tests\src\main\resources
[INFO]
[INFO] --- compiler:3.13.0:compile (default-compile) @ caffeine-tests ---
[INFO] Nothing to compile - all classes are up to date.
[INFO]
[INFO] --- resources:3.3.1:testResources (default-testResources) @ caffeine-tests ---
[INFO] skip non existing resourceDirectory C:\Users\***\Caffeine Tests\src\main\resources
[INFO]
[INFO] --- compiler:3.13.0:testCompile (default-testCompile) @ caffeine-tests ---
[INFO] Nothing to compile - all classes are up to date.
[INFO]
[INFO] --- surefire:3.3.0:test (default-test) @ caffeine-tests ---
[WARNING] useSystemClassLoader setting has no effect when not forking
[WARNING] The parameter forkCount should likely not be 0. Forking a JVM for tests improves test accuracy. Ensure to have a <forkCount> >= 1.
[INFO] Using auto detected provider org.apache.maven.surefire.junit4.JUnit4Provider
[INFO] Running caffeine.test.TestCaffeine

TestCaffeine代码 #

package caffeine.test;

import junit.framework.Test;
import junit.framework.TestSuite;

public final class TestCaffeine extends junit.framework.TestSuite {
    public TestCaffeine() {
        super();
    }
    public TestCaffeine(final Class theClass) {
        super(theClass);
    }
    public TestCaffeine(final String name) {
        super(name);
    }
    public static Test suite() {
        final TestCaffeine suite = new TestCaffeine();

            suite.addTest(new TestSuite(
                caffeine.test.aggregation3.CaffeineLauncher.class));
            suite
                .addTest(new TestSuite(caffeine.test.array.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.association1.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.association2.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.collection.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition1.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition2.CaffeineLauncher.class));
        suite.addTest(new TestSuite(
            caffeine.test.composition3.CaffeineLauncher.class));
        suite.addTest(new TestSuite(
            caffeine.test.composition4.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition5.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition6.counterexample.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition7.counterexample.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition8.counterexample.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.composition9.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.interactiondiagram1.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.interactiondiagram2.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.multithreading1.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.multithreading2.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.nextEvent2.CaffeineLauncher.class));
            suite.addTest(new TestSuite(
                caffeine.test.nextEvent3.CaffeineLauncher.class));

        return suite;
    }
}

pom.xml配置 #

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>net.ptidej</groupId>
        <artifactId>all-ptidej</artifactId>
        <version>1.0.0</version>
    </parent>
    <groupId>caffeine-tests</groupId>
    <artifactId>caffeine-tests</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.13.0</version>
                <configuration>
                    <release>21</release>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>3.3.0</version>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>net.ptidej.caffeine</groupId>
            <artifactId>caffeine</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <scope>test</scope>
        </dependency>

    </dependencies>
</project>

排查与解决步骤 #

1. 修复SureforkCount配置 #

日志明确提示forkCount=0不推荐，会影响测试准确性。修改Surefire插件配置，开启fork模式：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>3.3.0</version>
    <configuration>
        <forkCount>1</forkCount>
        <reuseForks>true</reuseForks>
    </configuration>
</plugin>

执行mvn clean test重新测试。

2. 检查依赖兼容性 #

• 执行mvn dependency:tree查看测试依赖树，排查是否存在重复或冲突的JUnit相关依赖，若有则在JUnit依赖中添加<exclusions>排除冲突项。
• 尝试调整Surefire版本至3.2.5，或确认net.ptidej.caffeine依赖与JDK 21的兼容性。

3. 调试runBare方法 #

挂起发生在CaffeineLauncher.runBare()，需重点排查：

• 在该方法中添加关键步骤日志（初始化、资源加载、线程操作等），定位挂起点。
• 使用jstack <进程PID>查看线程栈，检查是否存在死锁、线程等待未唤醒的情况。

4. 切换JUnit 4风格测试套件 #

当前测试套件为JUnit 3风格，尝试改为JUnit 4注解式：

package caffeine.test;

import org.junit.runner.RunWith;
import org.junit.runners.Suite;
import caffeine.test.aggregation3.CaffeineLauncher;

@RunWith(Suite.class)
@SuiteClasses({
    CaffeineLauncher.class,
    caffeine.test.array.CaffeineLauncher.class,
    // 其他测试类依次添加
})
public class TestCaffeine {
}

重新执行测试验证。

5. 调整JDK编译版本 #

旧项目可能基于低版本JDK开发，修改maven-compiler-plugin的<release>配置为对应版本（如8、11），重新编译测试。

6. 清理Maven缓存 #

执行以下命令彻底清理缓存并重新拉取依赖：

mvn clean install -U

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