SpringBoot实战
Spring boot + Mybatis 整合
Spring boot+Mybatis，相对于原来的Spring+SpringMVC+Mybatis简单好多
一、java web开发环境搭建
参考教程：https://www.jianshu.com/p/39dec5a0ab55
二、Spring boot搭建
1、Intellij idea菜单栏File->new->project
创建新项目
2、选择左侧栏中spring initializr，右侧选择jdk版本，以及默认的Service URL，点击next。
选择JDK和默认URL
3、然后填写项目的Group、Artifact等信息，helloworld阶段选默认就可以了，点击next。
自定义包名
4、左侧点击Web选择web，SQL选择Mybatis、MYSQL（数据库用的是mysql，大家可以选择其他DB），点击next。
选择组件
5、填写Project name 等信息，然后点击Finish。
选择项目名称和地址
6、一个maven web项目就创建好了，目录结构如下：
项目创建完成
Spring boot就搭建好了，pom.xml里已经有了Spring boot的jar包，包括我们的mysql数据连接的jar包。Spring boot内置了类似tomcat这样的中间件，所以，只要运行DemoApplication中的main方法就可以启动项目了。
在src/main/java下新建目录com/demo/entity/User
package com.example.demo.entity;
public class User {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
相同demo目录下新建controller/TestBootController
package com.example.demo.controller;
import com.example.demo.entity.User;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@EnableAutoConfiguration
@RequestMapping("/boot")
public class TestBootController {
@RequestMapping("/user")
public User getUser(){
User user = new User();
user.setName("boot_test");
return user;
}
}
Spring boot启动默认是要加载数据源的，所以我们在src/main/resources下新建application.yml
数据库使用的是mysql。可根据自己的需求更换数据库
#默认使用配置
spring:
profiles:
active: dev
#公共配置与profiles选择无关
mybatis:
typeAliasesPackage: com.example.demo.entity
mapperLocations: classpath:mapper/*.xml
--- #分隔线不能少
#开发配置
spring:
profiles: dev
datasource:
url: jdbc:mysql://localhost:3306/test #数据库地址+数据库名字(自定义)
username: root #帐号(自定义)
password: root #密码(自定义)
driver-class-name: com.mysql.jdbc.Driver #驱动
将pom.xml中加载数据源的jar包先注释掉也可以。
/*<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>*/
最终结构springboot目录如下
启动DemoApplication的main方法，访问http://localhost:8080/boot/user即可
ps:如果自定义了包名等~复制代码请注意修改对应包名
三、整合Mybatis
1、集成druid，使用连接池。pom.xml中添加：
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.0</version>
</dependency>
最终的pom.xml文件：
<?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.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo</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>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
到此Spring boot 就完成整合了~ 可以运行测试下能否顺利运行。
2.用MyBatis Generator自动生成代码，或者自定义编写各层
最终目录请看文章最后
public class User {
private Integer id;
private String userName;
private String password;
private Integer age;
//省略get set方法...
}
public interface UserDao {
int insertSelective(User record);
User selectByPrimaryKey(Integer id);
}
UserMapper.xml 中注意替换成自己的User对象地址 type 和parameterType
<?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.xc.dao.UserDao" ><!--修改自定义地址 -->
<resultMap id="BaseResultMap" type="com.xc.entity.User" ><!--修改自定义地址 -->
<id column="id" property="id" jdbcType="INTEGER" />
<result column="user_name" property="userName" jdbcType="VARCHAR" />
<result column="password" property="password" jdbcType="VARCHAR" />
<result column="age" property="age" jdbcType="INTEGER" />
</resultMap>
<sql id="Base_Column_List" >
id, user_name, password, age
</sql>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
select
<include refid="Base_Column_List" />
from user_t
where id = #{id,jdbcType=INTEGER}
</select>
<insert id="insertSelective" parameterType="com.xc.entity.User" ><!--修改自定义地址 -->
insert into user_t
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="id != null" >
id,
</if>
<if test="userName != null" >
user_name,
</if>
<if test="password != null" >
password,
</if>
<if test="age != null" >
age,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="id != null" >
#{id,jdbcType=INTEGER},
</if>
<if test="userName != null" >
#{userName,jdbcType=VARCHAR},
</if>
<if test="password != null" >
#{password,jdbcType=VARCHAR},
</if>
<if test="age != null" >
#{age,jdbcType=INTEGER},
</if>
</trim>
</insert>
</mapper>
3.修改DemoApplication.java，添加扫描dao层接口。
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.demo.dao") //修改成自己的dao地址
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
4.添加Service/impl 和Controller层
public interface UserService {
public User getUserById(int userId);
boolean addUser(User record);
}
@Service("userService")
public class UserServiceImpl implements UserService {
@Resource
private UserDao userDao;
@Override
public User getUserById(int userId) {
return userDao.selectByPrimaryKey(userId);
}
@Override
public boolean addUser(User record) {
boolean result = false;
try {
userDao.insertSelective(record);
result = true;
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
}
@RestController
@EnableAutoConfiguration
@RequestMapping("/boot")
public class TestBootController {
@Resource
private UserService userService;
@RequestMapping("/user")
@ResponseBody
public User getUser(HttpServletRequest request, Model model){
int userId = Integer.parseInt(request.getParameter("id"));
User user = this.userService.getUserById(userId);
return user;
}
}
5.Mysql创建测试表和插入数据
DROP TABLE IF EXISTS `user_t`;
CREATE TABLE `user_t` (
`id` int(11) NOT NULL DEFAULT '0',
`user_name` varchar(255) DEFAULT NULL,
`password` varchar(255) DEFAULT NULL,
`age` int(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of user_t
-- ----------------------------
INSERT INTO `user_t` VALUES ('0', 'bb', 'bb', '11');
INSERT INTO `user_t` VALUES ('1', 'aa', 'aaa', '11');
6.浏览器访问http://localhost:8080/boot/user?id=1
最终结果展示
7.最终项目结构图
最终项目结构图
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