springboot+mybatis简单实例
springboot整合mybatis
SpringBoot简介:
核心
1、pom.xml,通过依赖引入jar包,不必再自己下载什么的。由maven统一管理。
2、由java自身的class加载配置信息,而不是通过.xml的配置文件加载。
3、自身有Tomcat,启动由自身的被@SpringBootApplication 注解的main程序入口,而不是启动Tomcat等等。
mybatis简介(是一个支持动态Sql语句的持久层框架):
核心
1、Mapper.xml,由Mapper.xml文件与数据库映射,表、字段一一对应,然后写出需要执行的SQL语句。
2、Mapper接口,由java写的Mapper接口与Mapper.xml文件对应(接口的方法与.xml的SQL语句一一对应)
数据库中表格为Xuser,只有三个字段:xuser_id、xuser_age、xuser_name
源代码:
https://github.com/mengyuxiaofeng/SpringBoot
项目结构如下:
一、pom.xml中加入需要的jar包依赖
核心的依赖如下
SpringBoot核心
SpringBoot的web
mybatis的依赖
连接数据库MySQL的依赖
具体的pom.xml文件如下:
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.huoli</groupId>
<artifactId>SpringBootDemo</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>SpringBootDemo Maven Webapp</name>
<url>http://maven.apache.org</url>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.6.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</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-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</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>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>SpringBootDemo</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
二、配置连接数据库(JDBC)的参数,以及mybatis的Mapper.xml的位置
具体的application.yml如下:
spring:
datasource:
url: jdbc:mysql://221.235.53.167:3306/gttest?characterEncoding=utf8
username: gttest
password: gttest0319
driver-class-name: com.mysql.jdbc.Driver
mybatis:
mapper-locations: classpath:mapper/*.xml
三、建立实体Xuser
Xuser如下:
package com.huoli.demo.entity;
import java.io.Serializable;
public class Xuser implements Serializable{
private int id;
private String name;
private int age;
public int getId()
{
return id;
}
public String getName()
{
return name;
}
public int getAge()
{
return age;
}
public void setId(int id)
{
this.id = id;
}
public void setName(String name)
{
this.name = name;
}
public void setAge(int age)
{
this.age = age;
}
}
四、通过XuserMapper接口、XuserMapper.xml、DataSourceConfig实现数据库操作(核心)
连接数据库是由DataSourceConfig实现,它实例化了一个DataSource。整个DataSourceConfig相当于一个.xml的配置文件,类似于以前的applicationContext.xml。
如下:
package com.huoli.demo.config;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import org.apache.tomcat.jdbc.pool.DataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class DataSourceConfig {
@ConfigurationProperties(prefix = "spring.datasource")
@Bean
public DataSource dataSource(){
return new DataSource();
}
}
对数据库的增删改查操作是通过XuserMapper.xml实现的。
有两个需要注意的地方:namespace以及type
namespace指明了对应的XuserMapper接口:
<mapper namespace="com.huoli.demo.Mapper.XuserMapper" >
type指明了对应的实体Xuser
<resultMap id="BaseResultMap" type="com.huoli.demo.entity.Xuser" >
具体如下
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.huoli.demo.Mapper.XuserMapper" >
<resultMap id="BaseResultMap" type="com.huoli.demo.entity.Xuser" >
<id column="xuser_id" property="id" jdbcType="BIGINT" />
<result column="xuser_name" property="name" jdbcType="VARCHAR" />
<result column="xuser_age" property="age" jdbcType="BIGINT" />
</resultMap>
<sql id="Base_Column_List" >
xuser_id, xuser_name, xuser_age
</sql>
<select id="getAll" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM xuser
</select>
<select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM xuser
WHERE id = #{id}
</select>
<insert id="insert" >
INSERT INTO
xuser
(xuser_id,xuser_name,xuser_age)
VALUES
(#{id}, #{name}, #{age})
</insert>
<delete id="delete" parameterType="java.lang.Long" >
DELETE FROM
xuser
WHERE
xuser_id =#{id}
</delete>
</mapper>
最后的XuserMapper接口是Controller调用的,XuserController是没法直接调用XuserMapper.xml中的方法,必须调用XuserMapper接口中的方法,而XuserMapper接口中的方法是与XuserMapper.xml中的方法一一对应的。
具体如下:
package com.huoli.demo.Mapper;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import com.huoli.demo.entity.Xuser;
@Mapper
public interface XuserMapper {
List<Xuser> getAll();
Xuser getOne(Long id);
void insert(Xuser user);
void update(Xuser user);
void delete(Long id);
}
五、建立XuserController实现页面交互
具体如下:
package com.huoli.demo.controller;
import java.util.List;
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import com.huoli.demo.Mapper.XuserMapper;
import com.huoli.demo.entity.Xuser;
@RestController
public class XuserController {
@Autowired
private XuserMapper xuserMapper;
@RequestMapping("getUsers")
public List<Xuser> getUsers() {
List<Xuser> users=xuserMapper.getAll();
return users;
}
@RequestMapping("getUser")
public Xuser getUser(Long id) {
Xuser user=xuserMapper.getOne(id);
return user;
}
@RequestMapping("add")
public void save(Xuser user) {
xuserMapper.insert(user);
}
// @RequestMapping(value="update")
// public void update(Xuser user) {
// xuserMapper.update(user);
// }
@RequestMapping(value="delete/{id}")
public void delete(@PathVariable("id") Long id) {
xuserMapper.delete(id);
}
@RequestMapping(value = "hello", method = RequestMethod.GET)
public String hello(Map<String,Object> map){
return "饶你吗";
}
}
六、通过Start.class(被@SpringBootApplication注释的含有main的启动类)发布,就像运行一个简单的程序一样。运行@SpringBootApplication注释的main函数就行了。
package com.huoli.demo;
import java.util.Map;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
@SpringBootApplication
@SpringBootConfiguration
@EnableAutoConfiguration
//@ComponentScan("controller")
//@ComponentScan(basePackages = {"com.huoli.demo.controller"})
public class Start {
@RequestMapping("hello1")
@ResponseBody
public String hello(Map<String,Object> map){
return "饶你吗1";
}
public static void main(String[] args) {
SpringApplication.run(Start.class, "--server.port=9999");//后面是直接设置端口号
}
}
七、在浏览器中查看
在浏览器中输入:
http://localhost:9999/getUsers
可以得到页面: