java - Maven - 包不存在

Question

我正在尝试构建我的项目，但我一直收到错误消息，说该包不存在，为什么 IDE 说它没问题(没有编译错误)。显然，我的 pom.xml 和 IDE 的编译方式有些不一致。

我的项目结构如下:

这是我的 pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://maven.apache.org/POM/4.0.0"
         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.oo</groupId>
    <artifactId>employeeservice</artifactId> <!-- Docker complains if the name contains upper case -->
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>EmployeeService</name>
    <description>This service takes care of all the employee related operations</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

如果我删除 Employee(实体)和 EmployeeRepository 并且只让 Controller 带有一个虚拟的“Hello World”，它工作正常!我试着把它们放在同一个包下，同一个问题!

员工类

package com.oo.employeeservice.dao.entity;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Employee {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    private String firtName;

    private String lastName;

    private String email;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getFirtName() {
        return firtName;
    }

    public void setFirtName(String firtName) {
        this.firtName = firtName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }


}

使用默认的 Spring 引导配置:

package com.oo.employeeservice;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MainApplication {

    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class, args);
    }

}

Controller

package com.oo.employeeservice.controller;

import com.oo.employeeservice.dao.EmployeeRepository;
import com.oo.employeeservice.dao.entity.Employee;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api")
public class EmployeeController {

    @Autowired
    private EmployeeRepository repo;

    @RequestMapping(method = RequestMethod.GET)
    public ResponseEntity<Iterable<Employee>> all() {
        return new ResponseEntity<Iterable<Employee>>(repo.findAll(), HttpStatus.OK);
    }

    @RequestMapping(method = RequestMethod.POST)
    public ResponseEntity<?> create(@RequestBody Employee employee) {
        repo.save(employee);
        return new ResponseEntity<String>(HttpStatus.CREATED);
    }

}

Maven 日志:

~/IdeaProjects/EmployeeService$ mvn clean install
[INFO] Scanning for projects...
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building EmployeeService 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:3.0.0:clean (default-clean) @ employeeservice ---
[INFO] Deleting /home/mahdi/IdeaProjects/EmployeeService/target
[INFO] 
[INFO] --- maven-resources-plugin:3.0.1:resources (default-resources) @ employeeservice ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ employeeservice ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to /home/mahdi/IdeaProjects/EmployeeService/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/dao/EmployeeRepository.java:[3,41] package com.oo.employeeservice.dao.entity does not exist
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/dao/EmployeeRepository.java:[9,60] cannot find symbol
  symbol: class Employee
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[4,41] package com.oo.employeeservice.dao.entity does not exist
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[18,36] cannot find symbol
  symbol:   class Employee
  location: class com.oo.employeeservice.controller.EmployeeController
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[23,50] cannot find symbol
  symbol:   class Employee
  location: class com.oo.employeeservice.controller.EmployeeController
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[19,44] cannot find symbol
  symbol:   class Employee
  location: class com.oo.employeeservice.controller.EmployeeController
[INFO] 6 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.872 s
[INFO] Finished at: 2018-07-15T15:59:38+08:00
[INFO] Final Memory: 31M/308M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project employeeservice: Compilation failure: Compilation failure: 
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/dao/EmployeeRepository.java:[3,41] package com.oo.employeeservice.dao.entity does not exist
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/dao/EmployeeRepository.java:[9,60] cannot find symbol
[ERROR]   symbol: class Employee
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[4,41] package com.oo.employeeservice.dao.entity does not exist
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[18,36] cannot find symbol
[ERROR]   symbol:   class Employee
[ERROR]   location: class com.oo.employeeservice.controller.EmployeeController
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[23,50] cannot find symbol
[ERROR]   symbol:   class Employee
[ERROR]   location: class com.oo.employeeservice.controller.EmployeeController
[ERROR] /home/mahdi/IdeaProjects/EmployeeService/src/main/java/com/oo/employeeservice/controller/EmployeeController.java:[19,44] cannot find symbol
[ERROR]   symbol:   class Employee
[ERROR]   location: class com.oo.employeeservice.controller.EmployeeController
[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

Answer 1

我发现了 Intellij 最愚蠢的问题。如果您在所附图片的包资源管理器中查找 Employee 类，您可以看到该文件被标记为一个类。当我在终端中打开文件位置时，我意识到它没有“.java”扩展名。显然，maven 不会将该文件识别为 java 文件!