之前用注解shix实现了这个,但注解也有它的不足。在复杂的大项目中通常用的都是配置文件。
且在springboot2里面有好多坑,自己调了大半天终于调通了,所以记录一下,免得下次再犯。
本次用的是springboot2.0.3 + maven 3.2.2 +jdk1.8
而且发现有时候版本的问题跟maven有很大的关系,同样的springboot2.X ,但maven的版本不一样,所需的一些jar的版本也不一定一样。
例如:若maven是3.3.9,
<!-- 分页插件 -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.1.2</version>
</dependency>
<!-- alibaba的druid数据库连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.0</version>
</dependency>
这个可以
若:maven是3.2.2.
<!-- 分页插件 -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.5</version>
</dependency>
<!-- alibaba的druid数据库连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.9</version>
</dependency>
贴代码:
项目结构:
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>com.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>mybatis</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>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- alibaba的druid数据库连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.9</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.yml
server:
port: 8087
spring:
datasource:
name: test
url: jdbc:mysql://127.0.0.1:3306/mydream
username: root
password: root
# 使用druid数据源
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
filters: stat
maxActive: 20
initialSize: 1
maxWait: 60000
minIdle: 1
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: select 'x'
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
maxOpenPreparedStatements: 20
mybatis:
mapper-locations: classpath:mapping/*/*.xml #这里是mapper的配置文件
type-aliases-package: com.mydream.backstate.*.entity #这里是实体类的包
#pagehelper分页插件
pagehelper:
helperDialect: mysql
reasonable: true
supportMethodsArguments: true
params: count=countSql
dao:
package com.mydream.backstate.sysuser.dao;
import com.mydream.backstate.sysuser.entity.SysUser;
public interface SysUserMapper {
SysUser findByUsername(String username);
}
entity:
package com.mydream.backstate.sysuser.entity;
public class SysUser {
private Long id;
private String password;
private String username;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password == null ? null : password.trim();
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username == null ? null : username.trim();
}
}
service:
package com.mydream.backstate.sysuser.service;
import com.mydream.backstate.sysuser.entity.SysUser;
/**
* Created by lpw'ASUS on 2018/7/20.
*/
public interface SysUserService {
SysUser findByUsername(String username);
}
serviceimpl:
package com.mydream.backstate.sysuser.service;
import com.mydream.backstate.sysuser.dao.SysUserMapper;
import com.mydream.backstate.sysuser.entity.SysUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* Created by lpw'ASUS on 2018/7/20.
*/
@Service
public class SysUserServiceImpl implements SysUserService {
@Autowired
private SysUserMapper sysUserMapper;
@Override
public SysUser findByUsername(String username) {
return sysUserMapper.findByUsername(username);
}
}
controller:
package com.mydream.backstate.sysuser.controller;
import com.mydream.backstate.sysuser.entity.SysUser;
import com.mydream.backstate.sysuser.service.SysUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
/**
* Created by lpw'ASUS on 2018/7/20.
*/
@Controller
@RequestMapping("/")
public class SysUserController {
@Autowired
private SysUserService sysUserService;
@RequestMapping("test")
@ResponseBody
public SysUser test(@RequestParam String username){
return sysUserService.findByUsername(username);
}
}
SysUserMapper.xml
<?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.mydream.backstate.sysuser.dao.SysUserMapper">
<resultMap id="BaseResultMap" type="com.mydream.backstate.sysuser.entity.SysUser" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="password" property="password" jdbcType="VARCHAR" />
<result column="username" property="username" jdbcType="VARCHAR" />
</resultMap>
<sql id="BASE_TABLE">
sys_user
</sql>
<sql id="BASE_COLUMN">
id,password,username
</sql>
<select id="findByUsername" resultMap="BaseResultMap" parameterType="string">
SELECT
<include refid="BASE_COLUMN"/>
FROM
<include refid="BASE_TABLE"/>
WHERE username = #{username}
</select>
</mapper>
在使用的过程中我刚开始碰到,mapper类shan上面不加@Mapper,就会发现报zhao找不到的错误,之后查了发现,要么每个Mapper类都加这个,要么在启动类上面加
@MapperScan("com.mydream.backstate.*.dao")
例:
package com.mydream.backstate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.mydream.backstate.*.dao")
public class MydreamApplication {
public static void main(String[] args) {
SpringApplication.run(MydreamApplication.class, args);
}
}