创建名称为“dataSource”的 bean Spring Boot Hibernate 时出错

Question

我在启动有关如何访问 mysql 数据的 spring 指南时遇到了一些问题（请参阅此链接： https ://spring.io/guides/gs/accessing-data-mysql/）。我稍微调整了类，所以我有这段代码：

1. pom.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.springframework</groupId>
       <artifactId>gs-mysql-data</artifactId>
       <version>0.1.0</version>

       <parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>1.5.6.RELEASE</version>
   </parent>

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

   <!-- JPA Data (We are going to use Repositories, Entities, Hibernate, etc...) -->

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

   <!-- Use MySQL Connector-J -->

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

   <properties>
       <java.version>1.8</java.version>
   </properties>

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

我正在使用这个主控制器： MainController.java

 import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

import com.resource.iPbackend.UserRepository;
import com.resource.iPbackend.User;

@Controller
@RequestMapping(path = "/main")
public class MainController {

    @Autowired
    private UserRepository userRepository;

    @RequestMapping(path = "/reg", method = RequestMethod.POST)
    public @ResponseBody String regNewUser (@RequestParam String firstName,      @RequestParam String lastName, @RequestParam String email, @RequestParam String password, @RequestParam String username) {
        User n = new User();
        n.setFirstName(firstName);
        n.setLastName(lastName);
        n.setEmail(email);
        n.setPassword(password);
        n.setUsername(username);
        userRepository.save(n);
        return "User is stored in database: " + n;
    }

    @GetMapping(path = "/all")
    public @ResponseBody Iterable<User> getAllUsers() {
        return userRepository.findAll();
    }
}

连同这个存储库： UserRepository.java

 import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.resource.iPbackend.User;

@Repository
public interface UserRepository extends CrudRepository<User, Long> {

}

这个实体： User.java

 import org.springframework.data.annotation.Id;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    private String firstName;
    private String lastName;
    private String email;
    private String password;
    private String username;

    public Integer getId() {
        return id;
    }

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

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    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;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

最后我有了这个 Application.class：

 @EnableAutoConfiguration
@SpringBootApplication
public class IPbackendApplication {

public static void main(String[] args) {

    SpringApplication.run(IPbackendApplication.class, args);
}
}

我收到此错误：

org．嵌套异常是 org.springframework.beans.factory.BeanCreationException：在类路径资源 [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Tomcat.class] 中创建名称为“dataSource”的 bean 时出错：通过工厂方法实例化 Bean 失败;嵌套的异常是 org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.tomcat.jdbc.pool.DataSource]: Factory method ‘dataSource’ throw exception;嵌套异常是 java.lang.IllegalArgumentException：URL 必须以 org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.3.10.RELEASE.jar 中的“jdbc”开头:4.3.10.RELEASE] 在 org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] 在 org .springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]

谢谢你的帮助！

原文由 justus 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

在异常跟踪中查看此消息：

嵌套的异常是 org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.tomcat.jdbc.pool.DataSource]: Factory method ‘dataSource’ throw exception;嵌套异常是 java.lang.IllegalArgumentException： URL 必须以 org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) 中的“jdbc”开头

您很可能没有提供 application.properties 文件，该文件对 spring.datasource.url 属性进行赋值。

否则你没有正确评价它。

它应该看起来像：

 spring.datasource.url=jdbc:mysql://localhost/mydb

可以参考 Spring Boot 文档。

原文由 davidxxx 发布，翻译遵循 CC BY-SA 3.0 许可协议