Question

即使我在控制台中执行了所有正确配置的设置和休眠查询，但是如果我们检查数据库值的数量和类别是否作为NULL值插入，即使我使用了Crud存储库，Springboot也会插入NULL值

Ticket.java

package com.vinay.api.model;

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

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import lombok.ToString;

@Entity
@Table(name = "Ticket")
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString
public class Ticket {

    @Id
    @GeneratedValue
    private int id;
    private double amount;
    private String category;

}

TicketDao.java

package com.vinay.api.dao;

import org.springframework.data.repository.CrudRepository;

import com.vinay.api.model.Ticket;

public interface TicketDao extends CrudRepository<Ticket, Integer>{

}

TicketController.java

package com.vinay.api.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.vinay.api.dao.TicketDao;
import com.vinay.api.model.Ticket;

@RestController
@RequestMapping("/tickets")
public class TicketController {

    @Autowired
    private TicketDao ticketDao;

    @PostMapping("/bookTickets")
    public String bookTicket(@RequestBody List<Ticket> tickets)
    {
        ticketDao.saveAll(tickets);
        return "tickets booked: "+tickets.size();
    }

    @GetMapping("/getTickets")
    public List<Ticket> getTickets()
    {
        return (List<Ticket>) ticketDao.findAll();
    }
}

SpringMysqlApplication.java

package com.vinay.api;

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

@SpringBootApplication
public class SpringMysqlApplication {

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

}

application.properties

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url= jdbc:mysql://localhost:3306/ticket
spring.datasource.username= root
spring.datasource.password=
spring.jpa.show-sql= true
spring.jpa.hibernate.ddl-auto= update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>spring-mysql</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-mysql</name>
    <description>Springboot mysql</description>

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

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

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

</project>

Answer 1

尝试指定生成类型策略。

@GeneratedValue(strategy=GenerationType.AUTO)

还使用包装器类而不是原始数据类型。将int更改为Integer。

private Integer id

Answer 2

我能够解决此问题，因为我没有在IDE中配置lambok，所以我使用了手动吸气器，而setter则删除了@getter和@Setter注释，帮助我解决了这个问题

Springboot Crud存储库插入空值

2 个答案: