执行mvn clean test（JUnit）时无法找到编译类及相关错误求助

项目结构 #

│   .classpath
│   .project
│   LICENSE.txt
│   NOTICE.txt
│   pom.xml
│   README.txt
├───site
└───src
    ├───main
    │   ├───java
    │   │   └───com
    │   │       └───daydreamer
    │   │           └───app
    │   │                   TestApp.java
    └───test
        ├───java
        │   └───com
        │       └───daydreamer
        │           └───app
        │                   TestAppTest.java

POM配置 #

<?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.daydreamer.app</groupId>
  <artifactId>testpkg</artifactId>
  <version>1</version>

  <properties>
    <maven.compiler.release>11</maven.compiler.release>
    <junit.version>5.8.2</junit.version>
  </properties>

  <build>
    <plugins>
      <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.22.2</version>
      </plugin>
      <plugin>
        <artifactId>maven-failsafe-plugin</artifactId>
        <version>2.22.2</version>
      </plugin>
    </plugins>
  </build>

  <dependencies>

    <dependency>
      <groupId>org.junit.platform</groupId>
      <artifactId>junit-platform-launcher</artifactId>
      <version>1.8.2</version>
      <scope>test</scope>
    </dependency>

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

  </dependencies>

</project>

主代码（TestApp.java） #

package com.daydreamer.app;

public class TestApp {

    // Fields
    private int a;

    // Constructor
    public TestApp(int a) {
        this.a = a;
    }

    // Getters
    public int getA() {
        return this.a;
    }

    // String representation
    @Override
    public String toString() {
        String strRepr = "TestApp {" + this.a + "}";
        return strRepr;
    }
}

测试代码问题与错误信息 #

原始测试代码（TestAppTest.java） #

import com.daydreamer.app.TestApp;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;


public class TestAppTest {

    @Test
    void getATest0() {
        var expected = 1;
        var actual = TestApp(1).getA();
        Assertions.assertEquals(actual, expected);
    }

    @Test
    void toStringTest1() {
        var expected = "1";
        var actual = TestApp(1).toString();
        Assertions.assertEquals(actual, expected);
    }
}

执行mvn clean test报错 #

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:testCompile (default-testCompile) on project testpkg: Compilation failure: Compilation failure:
[ERROR] ./src/test/java/com/daydreamer/app/TestAppTest.java:[11,22] cannot find symbol
[ERROR]   symbol:   method TestApp(int)
[ERROR]   location: class TestAppTest
[ERROR] ./src/test/java/com/daydreamer/app/TestAppTest.java:[18,22] cannot find symbol
[ERROR]   symbol:   method TestApp(int)
[ERROR]   location: class TestAppTest
[ERROR] -> [Help 1]

LSP提示 #

the declared package "" does not match the expected package "com.daydreamer.app"

修复方案 #

1. 修正对象实例化语法 #

Java中实例化对象必须使用new关键字调用构造方法，把TestApp(1)改为new TestApp(1)。

2. 添加正确的包声明 #

测试类位于com.daydreamer.app目录下，必须添加对应的包声明package com.daydreamer.app;，否则编译器会将其归为默认包，导致包不匹配错误。

3. 修正断言预期值 #

TestApp的toString方法返回格式为TestApp {1}，而非原始代码中的"1"，需要同步修正测试断言的预期值，避免测试执行失败。

修复后的完整测试代码 #

package com.daydreamer.app;

import com.daydreamer.app.TestApp;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;


public class TestAppTest {

    @Test
    void getATest0() {
        var expected = 1;
        var actual = new TestApp(1).getA();
        Assertions.assertEquals(actual, expected);
    }

    @Test
    void toStringTest1() {
        var expected = "TestApp {1}";
        var actual = new TestApp(1).toString();
        Assertions.assertEquals(actual, expected);
    }
}

验证修复 #

执行mvn clean test，编译和测试都会正常通过，LSP的包错误提示也会消失。

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