spring boot在项目中同时使用 jpa 与MyBatis操作数据库

it2025-09-28 2

spring boot mvc 基本配置和mybatis配置与操作请参考前面的博客。

小型项目可能jpa使用更便捷，在大型项目中更多会考虑安全和性能要求，在这方面半自动的mybatis则更具有优势。

本教程提供一个简单的spring boot数据库操作案例，包括了jpa和mybatis的整合，但本文主要给了jpa的数据库操作，而在示例代码中提供了jpa和mybatis的共同配置和使用，更详细的内容请参考官方文档（注意，由于spring boot版本之间差别，应该根据项目配置查看相应的帮助文档）：

https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#reference

项目结构如下：

1、在pom.xml添加依赖

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

application.properties文件内容（有jpa配置和mybatis配置）

spring. thymeleaf: prefix: "classpath:/templates/" suffix: ".html" spring.datasource.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true spring.datasource.username=root spring.datasource.password=root spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver # # Hikari will use the above plus the following to setup connection pooling spring.datasource.type=com.zaxxer.hikari.HikariDataSource spring.datasource.hikari.minimum-idle=10 spring.datasource.hikari.maximum-pool-size=25 spring.datasource.hikari.auto-commit=true spring.datasource.hikari.idle-timeout=3000 spring.datasource.hikari.pool-name=DatebookHikariCP spring.datasource.hikari.max-lifetime=200000 spring.datasource.hikari.connection-timeout=30000 spring.datasource.hikari.connection-test-query=SELECT 1 mybatis.typeAliasesPackage=com.example.demo.entity mybatis.mapper-locations=classpath:/mapper/*Mapper.xml #jpa configuration spring.jpa.hibernate.ddl-auto=update spring.jpa.show-sql=true

2、编写实体类（注意包的位置）

package com.example.demo.entity; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name="product") public class Product { @Id @GeneratedValue private Long id; @Column(nullable = false) private String productName; @Column(nullable = true) private String location; // @Column(nullable = false, unique = true) @Column(nullable = false) private String email; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getProductName() { return productName; } public void setProductName(String productName) { this.productName = productName; } public String getLocation() { return location; } public void setLocation(String location) { this.location = location; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public Product(String name,String location,String email){ this.productName=name; this.location=location; this.email=email; } public Product(){} }

注解一目了然，不多说

3、编写Dao类

package com.example.demo.dao; import java.util.List; import org.springframework.data.jpa.repository.Query; import org.springframework.data.repository.CrudRepository; import org.springframework.data.repository.query.Param; import com.example.demo.entity.Product; public interface ProductRepository extends CrudRepository<Product,Long>{ List <Product> findByProductName(String name); List <Product> findByProductNameContaining(String name); //原生态ssql查询 @Query(value="select * from product", nativeQuery=true) List <Product> MyQueryAll(); //以下是jpa提供的对象方式查询 @Query("select p from Product p") List <Product> MyQueryAll2(); @Query("select p from Product p where p.productName like %:name%") List <Product> MyQueryAll3(@Param("name") String name); @Query("select p.productName from Product p where p.productName like %:name%") List <String> MyQueryAll4(@Param("name") String name); }

上面代码中提供了原生态的sql查询@Query(value="select * from product", nativeQuery=true) 和若干jpa对象查询，注意他们之间的区别。代码比较简单不展开阐述。注意：@Param一定要引用org.springframework.data.repository.query.Param的，不用引用了mybatis的org.apache.ibatis.annotations.Param，否则要错误

4、编写Controller类

package com.example.demo.controllers; import java.util.List; import javax.annotation.Resource; import javax.servlet.http.HttpSession; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import com.example.demo.dao.ProductRepository; import com.example.demo.dao.UserDao; import com.example.demo.dao.UserMapper; import com.example.demo.entity.Product; import com.example.demo.entity.User; import com.example.demo.services.SearchService; @Controller public class HelloController { @Autowired SearchService sv; @Autowired UserMapper us; @Autowired UserDao userDao; @Autowired ProductRepository jpa; //以下是mybatis访问的数据库 @RequestMapping("/index") public String hello(Model m, HttpSession session) { m.addAttribute("person", "张三"); System.out.println(sv.getinformation("12345")); List<User> userlist = us.queryAllUser(); m.addAttribute("userlist", userlist); User sUser = new User(); sUser.setName("Admin"); sUser.setAge(30); session.setAttribute("sUser", sUser); User us = userDao.findById(6); System.out.println("通过注解方式获得的User信息如下："); System.out.println(us.getName()); return "index"; } //以下是用jpa访问的数据库 @RequestMapping("/testjpa") // @ResponseBody public String hello2(Model m) { Product pd = new Product(); pd.setLocation("厦门"); pd.setEmail("test@163.com"); pd.setProductName("显卡"); jpa.save(pd); List<Product> pdlist = jpa.findByProductNameContaining("鼠标"); m.addAttribute("pdlist", pdlist); List<Product> all = jpa.MyQueryAll(); for (Product p : all) System.out.println("产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "\n"); all = jpa.MyQueryAll2(); System.out.println("second query"); for (Product p : all) System.out.println("产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "\n"); all = jpa.MyQueryAll3("鼠标"); System.out.println("third query"); for (Product p : all) System.out.println("产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "\n"); List<String> strs = jpa.MyQueryAll4("鼠标"); System.out.println("fourth query"); for (String p : strs) System.out.println("产品名称:" + p + "\n"); return "result"; } }

5、增加一个Controller对重数据库中的结果，用java的stream进行二次查询操作。

package com.example.demo.controllers; import java.util.Comparator; import java.util.List; import java.util.stream.Collectors; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import com.example.demo.dao.ProductRepository; import com.example.demo.entity.Product; @RestController public class SteamController { @Autowired ProductRepository jpa; @RequestMapping("/stream") public String handler() { List<Product> plist = jpa.MyQueryAll(); // 筛选 List<Product> list2 = plist.stream().filter(a -> a.getLocation().equals("厦门")).collect(Collectors.toList()); String str = ""; for (Product p : list2) { str += "产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "<br/>"; System.out.println("产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "\n"); } // 排序 list2 = plist.stream().sorted(Comparator.comparing(Product::getProductName).reversed()) .collect(Collectors.toList()); str += "<br/><br/>排序后的输出：<br/><br/>"; System.out.println("排序后的输出："); for (Product p : list2) { str += "产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "<br/>"; System.out.println("产品名称:" + p.getProductName() + " 产地是:" + p.getLocation() + "\n"); } // 求和 Long sum = plist.stream().map(Product::getId).reduce(0L, (a, b) -> a + b); System.out.println(sum); sum = plist.stream().map(Product::getId).reduce(0L, Long::sum); System.out.println(sum); return str; } }

6、页面(thymeleaf模板)

result.html页面，用以显示jpa查询结果

index.html页面，用以显示mybatis查询结果

<!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/xhtml" xmlns:layout="http://www.ultraq.net.nz/web/thymeleaf/layout" > <head> <meta charset="UTF-8"> <title></title> </head> <body> <table border="1" cellspacing="0"> <tr> <th>姓名</th> <th>年龄</th> </tr> <tr th:each="user : ${userlist}" > <td th:text="${user.name}"></td> <td th:text="${user.age}"></td> </tr> </table> <br/> <span>th:text不能够写出 th: text 中间不能用空格</span> <div th:object="${session.sUser}"> <p>姓名: <span th:text="*{name}" >Sebastian</span>. </p> <p>年龄: <span th:text="*{age}" >Pepper</span>. </p> </div>  </div> </body> </html>

7、浏览器输出结果

（1）jpa输出结果

（2）mybatis输出结果

（3）jpa在控制台输出结果

（4）在页面stream查询操作输出

示例代码下载：https://pan.baidu.com/s/1xw38WFVRAvzd5kCnR9jBAA 提取码: pjhw 复制这段内容后打开百度网盘手机App，操作更方便哦

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