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查了很多教程和博客,基本都是把Spring Boot和Spring Data JPA放在一起用,个人用不惯JPA,所以直接Mybatis了,毕竟现在大部分人用的都是Mybatis,这章主要是写一个基础表的增删改查
首先搭建一个Spring Boot项目,项目结构和启动类如下
然后是pom.xml引入我们需要的包
<?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>pers.hong</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>2.0.4.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.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>
<!--mybatis的分页插件-->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.3</version>
</dependency>
<!--mysql连接-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
<!--druid包-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.9</version>
</dependency>
<!--lang工具包-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.6</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
数据库字段也很简单,主键设为自增
然后新建实体类User,同时生成两个构造器和toString方法
package pers.hong.demo.entity;
/**
* @Description:
* @Auther: hong
* @Date: 2018/8/9/009 16:22
*/
public class User {
private Integer id;
private String name;
private String password;
private String email;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public User(Integer id, String name, String password, String email) {
this.id = id;
this.name = name;
this.password = password;
this.email = email;
}
public User() {
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", password='" + password + '\'' +
", email='" + email + '\'' +
'}';
}
}
接下来写Dao层的代码,在写Dao层代码前,要先对yml文件进行配置
上面被注释掉的是不使用Druid连接池时的连接数据库的写法,下面除了原先的数据库配置,还有Druid的各项配置,包括最大最小连接数等(官方文档写的十分详细,这里就不细说了),然后是mybatis的配置,mapper-Location是存放mybatis的xml文件的路径,config-Location是mybatis配置文件的路径,type-aliases-package是指别名对应的实体类,配置了这个在config文件里就可以不用配置别名了,默认是小写,比如实体类User,别名就是user
mybatis的配置文件如下,配置了数据类型的别名
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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias type="java.lang.Integer" alias="Integer" />
<typeAlias type="java.lang.Long" alias="Long" />
<typeAlias alias="HashMap" type="java.util.HashMap" />
<typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" />
<typeAlias alias="ArrayList" type="java.util.ArrayList" />
<typeAlias alias="LinkedList" type="java.util.LinkedList" />
</typeAliases>
</configuration>
然后是Mapper接口和xml文件,增删改查基础方法
@Mapper
public interface UserMapper {
List<User> getUserById(@Param("id") Integer id);
List<User> getAllUser();
void updateUserEmailById(@Param("id") Integer id);
void deleteUserById(@Param("id") Integer id);
void insertUser(User user);
}
<?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="pers.hong.demo.mapper.UserMapper">
<resultMap id="BaseMap" type="user">
<id column="id" property="id" jdbcType="BIGINT"/>
<result column="name" property="name" jdbcType="VARCHAR"/>
<result column="password" property="password" jdbcType="VARCHAR"/>
<result column="email" property="email" jdbcType="VARCHAR"/>
</resultMap>
<sql id="BaseColumn">
id,name,password,email
</sql>
<insert id="insertUser" parameterType="user">
INSERT INTO t_user
(name,password,email)
VALUE
(#{name},#{password},#{email})
</insert>
<update id="updateUserEmailById" parameterType="Integer">
UPDATE t_user
SET
<if test="name != null ">name = #{name}</if>
<if test="password != null">password = #{password}</if>
email = #{email}
</update>
<delete id="deleteUserById" parameterType="Integer">
DELETE FROM t_user
WHERE id = #{id}
</delete>
<select id="getUserById" resultMap="BaseMap" parameterType="Integer">
SELECT
<include refid="BaseColumn"/>
FROM t_user
WHERE id = #{id}
</select>
<select id="getAllUser" resultMap="BaseMap">
SELECT
<include refid="BaseColumn"/>
FROM t_user
</select>
</mapper>
然后是service和实现层的代码,其实这一步没什么太大必要,因为demo没有做什么业务操作,但是为了后面对项目进行扩展,就先写着了
public interface UserService {
List<User> getAllUsers();
List<User> getUserById(@Param("id") Integer id);
void updateUserEmailById(@Param("id") Integer id);
void deleteUserById(@Param("id") Integer id);
void insertUser(User user);
}
----------------------------------------------------------
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserMapper userMapper;
@Override
public List<User> getAllUsers() {
return userMapper.getAllUser();
}
@Override
public List<User> getUserById(Integer id) {
return userMapper.getUserById(id);
}
@Override
public void updateUserEmailById(Integer id) {
userMapper.updateUserEmailById(id);
}
@Override
public void deleteUserById(Integer id) {
userMapper.deleteUserById(id);
}
@Override
public void insertUser(User user) {
userMapper.insertUser(user);
}
}
最后是controller层
package pers.hong.demo.controller;
import org.springframework.beans.factory.annotation.Autowired;
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.RestController;
import pers.hong.demo.entity.User;
import pers.hong.demo.service.UserService;
import java.util.ArrayList;
import java.util.List;
/**
* @Description:
* @Auther: hong
* @Date: 2018/8/9/009 17:03
*/
@RestController
public class UserController {
@Autowired
private UserService userService;
@RequestMapping(value = "/getAllUser",method = RequestMethod.GET)
public List<User> getAllUser(){
List<User> resultList = new ArrayList<>();
resultList = userService.getAllUsers();
return resultList;
}
@RequestMapping(value = "/getUserById/{id}",method = RequestMethod.GET)
public List<User> getUser(@PathVariable Integer id){
List<User> resultList = new ArrayList<>();
resultList = userService.getUserById(id);
return resultList;
}
@RequestMapping(value = "/updateUserById")
public void updateUser(@PathVariable Integer id){
userService.updateUserEmailById(id);
}
@RequestMapping(value = "/deleteUserById/{id}")
public void deleteUser(@PathVariable Integer id){
userService.deleteUserById(id);
}
@RequestMapping(value = "/insertUser")
public void insertUser(User user){
userService.insertUser(new User(null,"qqq","qqq","qqq"));
}
}
基本增删改查就完成了,让我们在浏览器中测试一下
下一章用Vue写下界面,不然修改删除都不好测OAO