有好一段时间没有学习新东西了，过了个十月一感觉事情还是越早做越好，废话不多说了，说一下用mybatis连接MySQL数据库，上一篇写了jdbc测试，我的数据库表还是原来的。由于从网上查的资料大部分都是eclipse，由于我是做Android开发的，习惯了ide，所以就硬着头皮来了，中间其实遇到过好多问题。
看一下工程结构
先说一下Java代码，dao是查询接口，model是ben和对应的查询语句的xml，我感觉这样有点不好，user.xml放在dao里面比较好，等理解了就知道了，由于我是初学者所以好多东西都不是很理解，后期会给出合理的包的定义
test是我做测试用的
再说一下resources，configuration是配置文件，log4j是日志打印，其他的暂时用不到。
好来看一下代码，我按照建文件的顺序给大家来，
首先需要有一个对象，对象根据数据库建
user.java
package com.fanyafeng.model;import java.util.Date;/*** Author： fanyafeng* Data： 16/10/11 14:56* Email: [email protected]*/public class User {private int id;private String username;private Date birthday;private String sex;private String address;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}@Overridepublic String toString() {return "User{" +"id=" + id +", username='" + username + '/'' +", birthday=" + birthday +", sex='" + sex + '/'' +", address='" + address + '/'' +'}';}}
iuserdao.java
package com.fanyafeng.dao;import com.fanyafeng.model.User;import java.util.List;/*** Author： fanyafeng* Data： 16/10/11 14:55* Email: [email protected]*/public interface IUserDao {public List<User> queryUserByName(String name);public User selectUserById(int id);public void add();public void del(int id);public void alter(int id);}
user.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"><!--resultType 指定单条记录返回的类型--><mapper namespace="com.fanyafeng.dao.IUserDao"><select id="selectUserById" parameterType="int" resultType="com.fanyafeng.model.User">select * from user where id = #{id}</select><!--'%${value}' 表示拼接sql串,只能使用value,有可能会引起sql注入的情况--><select id="queryUserByName" parameterType="String" resultType="com.fanyafeng.model.User">SELECT * FROM user WHERE username LIKE #{name}</select><!--INSERT INTO USER (id,username,sex,address) VALUE (null,"陈潇然","女","大学同学")--><insert id="add" parameterType="com.fanyafeng.model.User">insert into user (id,username,birthday,sex,address) values (#{id},#{username},#{birthday},#{sex},#{address})</insert></mapper>usertest.java
package com.fanyafeng.test;import com.fanyafeng.model.User;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.Reader;import java.util.Date;import java.util.List;/*** Author： fanyafeng* Data： 16/10/11 14:58* Email: [email protected]*/public class UserTest {private static SqlSessionFactory sqlSessionFactory;private static Reader reader;static {try {reader = Resources.getResourceAsReader("Configuration.xml");sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);} catch (IOException e) {e.printStackTrace();}}public static void main(String[] args) {SqlSession sqlSession = sqlSessionFactory.openSession();try {// User user = (User) sqlSession.selectOne("com.fanyafeng.dao.IUserDao.selectUserById", 2);// System.out.println(user.getAddress() + user.getSex() + user.getBirthday());// System.out.println(user.getId() + user.getUsername());////List<User> userList = sqlSession.selectList("com.fanyafeng.dao.IUserDao.queryUserByName", "%李宁%");for (int i = 0; i < userList.size(); i++) {System.out.println(userList.get(i).toString());}User user = new User();user.setId(100);user.setBirthday(new Date());user.setUsername("李宁");user.setSex("女");user.setAddress("家里蹲");int isAdd = sqlSession.insert("com.fanyafeng.dao.IUserDao.add", user);sqlSession.commit();//不要忘记} finally {sqlSession.close();}}}
configration.xml
<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><!--如果在mapper中进行配置了,此处可以省略配置--><!--<typeAliases>--><!--<typeAlias alias="User" type="com.fanyafeng.model.User"/>--><!--</typeAliases>--><!-- 和spring整合后 environments配置将废除--><environments default="development"><environment id="development"><!-- 使用jdbc事务管理--><transactionManager type="JDBC"/><!-- 数据库连接池--><dataSource type="POOLED"><property name="driver" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8"/><property name="username" value="root"/><property name="password" value=""/></dataSource></environment></environments><mappers><mapper resource="com/fanyafeng/model/User.xml"/></mappers></configuration>
log4j的话大家根据自己的爱好添加就好了，代码中注释写的很详细了，我就不细讲了，这里有个地方让我很憋屈，问了个大神才知道咋回事，截图中有target目录吧，这是编译好文件的存放位置，可是，问题来了，java文件给我编译好放在哪里了，可是非resource得xml文件没有给我放进去，丢出来了一个异常，查了好多资料答非所问，然后是这样解决的
看一下pom.xml文件，我更改后的，加了build标签中了
<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.fanyafeng</groupId><artifactId>mybatisdemo</artifactId><packaging>war</packaging><version>1.0-SNAPSHOT</version><name>mybatisdemo Maven Webapp</name><url>http://maven.apache.org</url><build><finalName>mybatisdemo</finalName><resources><resource><directory>src/main/resources</directory><includes><include>**/*.xml</include><include>**/*.properties</include></includes></resource><resource><directory>src/main/java</directory><includes><include>**/*.xml</include></includes></resource></resources></build><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>3.8.1</version><scope>test</scope></dependency><!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.38</version></dependency><!-- https://mvnrepository.com/artifact/org.mybatis/mybatis --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.2.8</version></dependency><!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 --><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId><version>1.7.21</version></dependency><!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api --><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.21</version></dependency><!-- https://mvnrepository.com/artifact/log4j/log4j --><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.17</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core --><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.5</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api --><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-api</artifactId><version>2.5</version></dependency><!-- https://mvnrepository.com/artifact/org.javassist/javassist --><dependency><groupId>org.javassist</groupId><artifactId>javassist</artifactId><version>3.18.1-GA</version></dependency><!-- https://mvnrepository.com/artifact/commons-logging/commons-logging --><dependency><groupId>commons-logging</groupId><artifactId>commons-logging</artifactId><version>1.1.1</version></dependency><!-- https://mvnrepository.com/artifact/cglib/cglib --><dependency><groupId>cglib</groupId><artifactId>cglib</artifactId><version>2.2.2</version></dependency><!-- https://mvnrepository.com/artifact/asm/asm --><dependency><groupId>asm</groupId><artifactId>asm</artifactId><version>3.3.1</version></dependency></dependencies></project>
这就可以了，我这里实现了查，增，别的正在学习中。
以上所述是小编给大家介绍的Intellij Mybatis连接Mysql数据库，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对武林网网站的支持！