请教：单元测试运行找不到类问题

[palmers]

代码目录结构是这样的:

├─src
│  ├─main
│  │  └─java
│  │      └─com
│  │          └─xx  Sample.java
│  └─test
│      └─java
│          └─com
│              └─xx SampleTest.java

设置 src/main/java 目录为 Source root, src/test/java 为 test source root SampleTest.java 测试类中有调用 Sample 类中的方法 当我运行 SampleTest 单元测试方法时，提示找不到 com.xx.Sample.java 请问 这是为什么呢？依赖项目其他模块代码也是找不到类 在 IDEA 中，不会提示编译错误，只有运行时，在 testCompile 阶段提示找不到类，在跳过测试构建是正常的 运行测试使用的本地 maven 仓库已经指向了我使用的本地仓库（从 debug 日志中看到）

请大家帮帮我 谢谢大家了

问题已经解决了！谢谢大家! 原因： maven插件maven-compiler-plugin配置问题导致 插件maven-compiler-plugin 配置

<configuration>
    <skipMain>true</skipMain>
</configuration>

我专门查询了插件 maven-compiler-plugin 该配置，是为了不编译main sources 文档: https://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html

<skipMain>	boolean	2.0	Set this to 'true' to bypass compilation of main sources. Its use is NOT 
                                              RECOMMENDED, but quite convenient on occasion.
                                             User property is: maven.main.skip.

至此，问题得到解决，由于自己对maven项目结构规范和使用插件以及maven插件生命周期不够熟悉，导致这期间我尝试修改test目录结构和添加pom配置 都是围绕 test来做 所以一直没能解决问题

[sutra]

贴出 mvn test 的输出大概会简单点。

[palmers]

源码:

[palmers]

```java
public class MethClazzTest {

@Test
public void sayHello() {
new MethClazz().sayHello();
}
}
```

```
$ mvn test
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] unit-testing [pom]
[INFO] test-module [jar]
[INFO]
[INFO] ----------------------< org.example:unit-testing >----------------------
[INFO] Building unit-testing 1.0-SNAPSHOT [1/2]
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] ----------------------< org.example:test-module >-----------------------
[INFO] Building test-module 1.0-SNAPSHOT [2/2]
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ test-module ---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ test-module ---
[INFO] Not compiling main sources
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ test-module ---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory E:\projects\unit-testing\test-module\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ test-module ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent!
[INFO] Compiling 1 source file to E:\projects\unit-testing\test-module\target\test-classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /E:/projects/unit-testing/test-module/src/test/java/org/example/d1/MethClazzTest.java:[14,13] 找不到符号
符号: 类 MethClazz
位置: 类 org.example.d1.MethClazzTest
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] unit-testing 1.0-SNAPSHOT .......................... SUCCESS [ 0.040 s]
[INFO] test-module 1.0-SNAPSHOT ........................... FAILURE [ 3.981 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.484 s
[INFO] Finished at: 2021-08-19T20:03:02+08:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.0:testCompile (default-testCompile) on project test-module: Compilation failure
[ERROR] /E:/projects/unit-testing/test-module/src/test/java/org/example/d1/MethClazzTest.java:[14,13] 找不到符号
[ERROR] 符号: 类 MethClazz
[ERROR] 位置: 类 org.example.d1.MethClazzTest
[ERROR]
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR] mvn <goals> -rf :test-module

```

[palmers]

@sutra 日志就是上面这样的

[sutra]

pom.xml 贴出来看看。

[sutra]

[INFO] unit-testing 1.0-SNAPSHOT .......................... SUCCESS [ 0.040 s]
[INFO] test-module 1.0-SNAPSHOT ........................... FAILURE [ 3.981 s]

你这好像放在两个 maven project 里，然后没有写依赖吧？

[palmers]

@sutra unit-testing 是 test-module 的父模块 然后单元测试在 test-module 模块中

[palmers]

```xml
<?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>org.example</groupId>
<artifactId>unit-testing</artifactId>
<packaging>pom</packaging>
<version>1.0-SNAPSHOT</version>
<modules>
<module>test-module</module>
</modules>

<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
<scope>test</scope>
</dependency>
</dependencies>

<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<skipMain>true</skipMain>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.2</version>
</plugin>
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.8.2</version>
<executions>
<execution>
<goals>
<goal>prepare-agent</goal>
</goals>
</execution>
<!-- attached to Maven test phase -->
<execution>
<id>report</id>
<phase>test</phase>
<goals>
<goal>report</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
```

[palmers]

test-module 模块
```xml
<parent>
<artifactId>unit-testing</artifactId>
<groupId>org.example</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>

<artifactId>test-module</artifactId>

<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
<scope>test</scope>
</dependency>
</dependencies>
```