maven非web项目整合mbatis实现CRUD
在编程开发中，通常提起maven、mybatis这些，咱们首先想到的就是javaweb的技术栈，好比spring、springboot。可是今天给你们介绍一个用maven整合mybatis的非web项目完成数据库CRUD。java
1 在idea中新建maven项目
直接新建便可，建立好后的项目结构以下mysql
在pom文件添加依赖web
<dependencies>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.21</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.5</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-api -->
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<version>5.7.0</version>
<scope>test</scope>
</dependency>
</dependencies>
同时为了防止打包后找不到静态资源，在pom文件中，添加build标签spring
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
2 建立数据库和pojo实体类
首先建立数据库sql
create DATABASE mybatis; USE mybatis; create table user( id int PRIMARY key not null, name VARCHAR(30) , pwd VARCHAR(30) ) ENGINE=INNODB; INSERT INTO `user`(`id`, `name`, `pwd`) VALUES (1, '卡卡罗特', '123456'); INSERT INTO `user`(`id`, `name`, `pwd`) VALUES (2, '阿笠博士', '12345'); INSERT INTO `user`(`id`, `name`, `pwd`) VALUES (3, '野原向日葵', '123'); INSERT INTO `user`(`id`, `name`, `pwd`) VALUES (4, '一拳超人', '12'); INSERT INTO `user`(`id`, `name`, `pwd`) VALUES (5, '库里林', '123321');
再建立包，在包下建立实体类，我这里建立了一个User类。数据库
package toutiao.pojo;
public class User {
int id;
String name; String pwd; public User() {
} public User(int id, String name, String pwd) {
this.id = id;
this.name = name;
this.pwd = pwd;
} public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getPwd() {
return pwd;
} public void setPwd(String pwd) {
this.pwd = pwd;
} @Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", pwd='" + pwd + '\'' +
'}';
}}
3 在resources文件夹下面建立mybatis-config.xml 配置文件
在这里设置数据库链接属性等。同时数据库链接动态配置等能够在application.properties文件中配置，在mybatis-config.xml中加载。apache
<?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> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai&useUnicode=true&character=UTF8"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> </configuration>
4 建立mybatisUtils工具类
在这个类中读取 mybatis-config.xml 建立 sqlSession。编程
package learn.utils;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactor;
static {
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource); sqlSessionFactor = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace(); } } public static SqlSession getSqlSession(){
return sqlSessionFactor.openSession();
}}
此时，项目的目录结构以下api
5 建立mapper接口文件
package toutiao.mapper;
import toutiao.pojo.User;
import java.util.List;
public interface UserMapper {
public List<User> getUserList();
}
6 在resources文件夹下面，建立对应mapper接口文件的xml文件
文件里面的sql语句的id对应接口文件的方法名（这里以查询为例）springboot
<?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="toutiao.mapper.UserMapper"> <select id="getUserList" resultType="toutiao.pojo.User"> select * from mybatis.user; </select> </mapper>
7 在mybatis-config.xml 里面将6中建立的xml文件添进去
由于是在resources中，因此mapper标签的resource路径直接就是从resources下面的文件夹开始
<?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> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai&useUnicode=true&character=UTF8"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <mapper resource="userMapper.xml"></mapper> </mappers> </configuration>
8 查询结果
在test包里面建立测试类
package learn.mapper;
import learn.pojo.User;
import learn.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.jupiter.api.Test;
import java.util.List;
public class UserMapperTest {
@Test
public void test(){
Sqlession sqlSession = MybatisUtils.getSqlSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
List<User> userList = userMapper.getUserList(); for(User user : userList){
System.out.println(user); } sqlSession.close(); }}