无法从我的Java类访问org.springframework.data

我正在编写一个在线教程，在我需要使用数据库和添加jpa的步骤中，我无法在我的项目中访问它

我已经成功地将依赖项放入pom.xml文件中，并且没有收到任何错误。我还可以通过application.properties文件访问SpringJPA。问题是，当我想扩展Crudepository时，它没有被识别……然后我意识到，当我手动导入时，它不会导入org.springframework.data

我已将maven设置为始终更新快照

这是我的pom.xml文件。对于格式设置，我深表歉意，但我无法使用intellij的正确格式将其全部显示在stackoverflow上：

<?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.example</groupId>
<artifactId>demo3</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo3</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
<relativePath/>
</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-data-jpa</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>

</dependencies>

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

奶酪等级：

package com.example.demo.models;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

@Entity
public class Cheese {

    @Id
    @GeneratedValue
    private int id;

    @NotNull
    @Size(min=3, max=20)
    private String name;

    @NotNull
    @Size(min=1, message = "Description must not be empty")
    private String description;


    public Cheese(String name, String description) {
        this.name = name;
        this.description = description;
    }

    public int getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

CheeseDao（使用Spring数据/积垢存储的接口）

package com.example.demo.models；
导入com.example.demo.models.Cheese；
公共级芝士多扩展积垢积垢{
}

将注释添加到DAO中，它应该是接口而不是类

@Repository
public interface CheeseDao extends JpaRepository<Cheese, Integer> {

}

---

您似乎缺少hibernate实体依赖项，要解决此问题，只需在下面添加依赖项即可

 <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
    </dependency>

org.hibernate
休眠实体管理器

更换

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>mysql-connector-java</artifactId>
</dependency>

org.springframework.boot
mysql连接器java

与

mysql
mysql连接器java

您可以在添加Crudepository的地方添加界面吗？另外，添加您得到的错误。刚才这样做了…错误是它无法解决Crudepository。当我深入研究这一点时，我发现我无法导入org.springframework.dataYes，它必须与SpringVresion相关，因为Crudepository是在Spring2.0.1版本中添加的。在哪里可以成功地构建项目？并验证.m2文件夹中确实存在jpa jar文件

@Autowired
private CheeseDao cheeseDao;

 <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
    </dependency>

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
</dependency>