Question

我尝试在Spring Boot中访问数据mysql。当我运行应用程序时。出现此错误

在类路径资源[org / springframework / boot / autoconfigure / orm / jpa / HibernateJpaConfiguration.class]中创建名称为'entityManagerFactory'的bean时出错：调用init方法失败；嵌套的异常是java.lang.NoClassDefFoundError：javassist / bytecode / ClassFile

我的代码是

控制器

@GetMapping(path="/add") 
public @ResponseBody String addNewUser (@RequestParam String name
        , @RequestParam String email) {
    UserPojo n = new UserPojo();
    n.setName(name);
    n.setEmail(email);
    userRepository.save(n);
    return "Saved";
}

服务是

@Service("service")
@Transactional
public class UserService {

@Autowired
private User user;

public void addUser(UserPojo pojo) {
    UserEntity userEntity = new UserEntity();
    userEntity.setCustomerName(pojo.getCustomerName());
    userEntity.setEmail(pojo.getEmail());
    user.save(userEntity);
  }
}

道是

public interface User extends CrudRepository<UserEntity, Integer> {

 }

实体是-

package com.example.entity;

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

 @Entity
 @Table(name = "customer")
 public class UserEntity {

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

@Column
private String customerName;

@Column
private String email;

public String getCustomerName() {
    return customerName;
}

public void setCustomerName(String customerName) {
    this.customerName = customerName;
}

public String getEmail() {
    return email;
}

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

我的Pojo

public class UserPojo {

private String customerName;

private String email;

public String getCustomerName() {
    return customerName;
}

public void setCustomerName(String customerName) {
    this.customerName = customerName;
}

public String getEmail() {
    return email;
}

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

}

我的pom.xml

<?xml version="1.0" encoding="UTF-8"?>

http://maven.apache.org/xsd/maven-4.0.0.xsd“> 4.0.0

<groupId>com.example</groupId>
<artifactId>Test</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>

<name>Test</name>
<description>Demo project for Spring Boot</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>

    <!-- 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>
</dependencies>


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

application.properties

spring.mvc.view.prefix=/WEB-INF/view/
spring.mvc.view.suffix=.jsp
server.port=8085
server.servlet.context-path=/finance

# Database
spring.datasource.url=jdbc:mysql://localhost:3306/test? 
autoReconnect=true&useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
# Hibernate           
hibernate.dialect: org.hibernate.dialect.MySQL5Dialect
hibernate.show_sql: true
hibernate.hbm2ddl.auto: create

Answer 1

我已经实施了您的项目。一切都很好。我正在逐步描述。我这样写我的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.avijit</groupId>
    <artifactId>bootproject</artifactId>
    <version>1.0-SNAPSHOT</version>



    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
    </parent>

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

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>

        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
        </dependency>

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

    <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>

</project>

然后我写了我的主类并为jsp页面创建了一个bean。

@SpringBootApplication
public class Main {

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


    @Bean
    public ViewResolver getViewResolver(){
        InternalResourceViewResolver resolver = new
                InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/jsp/");
        resolver.setSuffix(".jsp");
        resolver.setViewClass(JstlView.class);
        return resolver;
    }
}

此后，我编写了

这样的Controller类。

  @Autowired
    UserService userService;

    @RequestMapping(value="/sample", method= RequestMethod.GET)
    public String sample()
    {
        return "sample";
    }

    @RequestMapping(value="/sample", method= RequestMethod.POST)
    public String dosave(@RequestParam String name, @RequestParam String email)
    {
        UserPojo n = new UserPojo();
        n.setCustomerName(name);
        n.setEmail(email);
        userService.addUser(n);
        return "sample";
    }

已编辑的服务类别

@Autowired
private User user;

public void addUser(UserPojo pojo) {
    UserEntity userEntity = new UserEntity();
    userEntity.setCustomerName(pojo.getCustomerName());
    userEntity.setEmail(pojo.getEmail());
    user.save(userEntity);
  }

在复制代码时，我发现在控制器类中您犯了一个错误n.setName(name);，它是n.setCustomerName(name)。在我的财产文件中，我是这样写的。

spring.datasource.url =jdbc:mysql://127.0.0.1:3306/InternDatabase
spring.datasource.username = root
spring.datasource.password = 123456
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.ddl-auto = update

检查更新的代码，并告诉我们。

调用init方法失败；嵌套的异常是java.lang.NoClassDefFoundError：javassist / bytecode / ClassFile

1 个答案: