今天学习下SpringBoot集成mybatis,集成mybatis一般有两种方式，一个是基于注解的一个是基于xml配置的。今天先了解下基于注解的mybatis集成。
一、引入依赖项
因为是mybatis嘛,肯定是要有mybatis相关的,同时用的是mysql,所以也需要引入mysql相关的。
<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.11</version>
</dependency>
二、创建model
这里创建了一个User的model,这样方便与数据库的表对照，这里在mysql中创建了一个名为mybatis的数据库,里面创建了一个user的表.同时创建了枚举类UserSexEnum.
CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(20) DEFAULT NULL, `age` int(11) DEFAULT NULL, `sex` varchar(20) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;
package com.example.model;
import java.io.Serializable;
public class User implements Serializable{
@Override
public String toString() {
// TODO Auto-generated method stub
return "User [id=" + Id + ", name=" + Name + ", age=" + Age + "]";
}
public int getId() {
return Id;
}
public void setId(int id) {
Id = id;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public int getAge() {
return Age;
}
public void setAge(int age) {
Age = age;
}
private int Id;
private String Name;
private int Age;
private UserSexEnum Sex;
public UserSexEnum getSex() {
return Sex;
}
public void setSex(UserSexEnum sex) {
Sex = sex;
}
}
package com.example.model;
public enum UserSexEnum {
MAN, WOMAN
}
三、创建Mapper
这里需要把model与操作数据库的sql对照起来，用什么对照呢?那就需要创建一个mapper.这里有增删改查。
package com.example.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import com.example.model.*;;
public interface UserMapper {
@Select("SELECT * FROM user")
@Results({
@Result(property = "Sex", column = "sex", javaType = UserSexEnum.class),
@Result(property = "Name", column = "name")
})
List<User> getAll();
@Select("SELECT * FROM user WHERE id = #{id}")
@Results({
@Result(property = "Sex", column = "sex", javaType = UserSexEnum.class),
@Result(property = "Name", column = "name")
})
User getOne(int id);
@Insert("INSERT INTO user(name,age,sex) VALUES(#{name}, #{age}, #{sex})")
void insert(User user);
@Update("UPDATE user SET name=#{userName},age=#{age} WHERE id =#{id}")
void update(User user);
@Delete("DELETE FROM user WHERE id =#{id}")
void delete(int id);
}
四、配置扫描
上面配置了mapper,那怎么让系统知道mapper放在哪里呢?于是有了@MapperScan注解。
package com.example.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.mapper")
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
五、创建Controller
这里创建了UserController,一个是显示所有用户,一个是新增一个用户之后再显示所有用户。
package com.example.demo;
import java.util.List;
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.RequestMethod;
import com.example.mapper.UserMapper;
import com.example.model.User;
import com.example.model.UserSexEnum;
@Controller
@RequestMapping("/user")
public class UserController {
@Autowired
private UserMapper userMapper;
@RequestMapping(value = "/alluser.do",method = RequestMethod.GET)
public String getallusers(Model model) {
List<User> users=userMapper.getAll();
model.addAttribute("users", users);
return "userlist";
}
@RequestMapping(value = "/insert.do",method = RequestMethod.GET)
public String adduser(Model model) {
User user=new User();
user.setName("cuiyw");
user.setAge(27);
user.setSex(UserSexEnum.MAN);
userMapper.insert(user);
List<User> users=userMapper.getAll();
model.addAttribute("users", users);
return "userlist";
}
}
六、数据库配置
上面mapper也设置了,model也设置了,那要与数据库交互，肯定要配置数据库地址这些信息吧。这里在运行的时候还报了一个错误.nested exception is java.sql.SQLException: The server time zone value ‘?D1ú±ê×?ê±??‘ is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.在mysql中设置了下时区:set global time_zone=‘+8:00‘;
spring.mvc.view.prefix=/view/ spring.mvc.view.suffix=.jsp mybatis.type-aliases-package=com.example.model spring.datasource.driverClassName = com.mysql.cj.jdbc.Driver spring.datasource.url = jdbc:mysql://localhost:3306/mybatis spring.datasource.username = root spring.datasource.password = 123456
七、创建页面显示
这里还是按照上一博客用jsp显示数据。
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<table>
<tr><th>名字</th><th>年龄</th><th>性别</th></tr>
<c:forEach items="${users}" var="item">
<tr><td>${item.name}</td><td>${item.age}</td><td>${item.sex}</td></tr>
</c:forEach>
</table>
</body>
</html>
八、测试
这里先在浏览器打开http://localhost:8080/user/alluser.do，可以看到用户列表,然后输入http://localhost:8080/user/insert.do，就会看到列表显示多了一行数据。
九、小结
使用基于注解的集成mybatis比较省事方便，但有利有弊，对于多表相连的可能就不太方便，使用基于xml配置的可能就更会好些。
原文地址：https://www.cnblogs.com/5ishare/p/9292201.html
时间： 2024-08-27 14:15:14