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;
}
@Override
public 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 queryUserByName(String name);
public User selectUserById(int id);
public void add();
public void del(int id);
public void alter(int id);
}
user.xml
<mapper namespace="com.fanyafeng.dao.IUserDao">
<select id="selectUserById" parameterType="int" resultType="com.fanyafeng.model.User">
select * from user where id = #{id}
select>
<select id="queryUserByName" parameterType="String" resultType="com.fanyafeng.model.User">
SELECT * FROM user WHERE username LIKE #{name}
select>
<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 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
<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<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>4.0.0modelVersion>
<groupId>com.fanyafenggroupId>
<artifactId>mybatisdemoartifactId>
<packaging>warpackaging>
<version>1.0-SNAPSHOTversion>
<name>mybatisdemo Maven Webappname>
<url>http://maven.apache.orgurl>
<build>
<finalName>mybatisdemofinalName>
<resources>
<resource>
<directory>src/main/resourcesdirectory>
<includes>
<include>**/*.xmlinclude>
<include>**/*.propertiesinclude>
includes>
resource>
<resource>
<directory>src/main/javadirectory>
<includes>
<include>**/*.xmlinclude>
includes>
resource>
resources>
build>
<dependencies>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>3.8.1version>
<scope>testscope>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.38version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.2.8version>
dependency>
<dependency>
<groupId>org.slf4jgroupId>
<artifactId>slf4j-log4j12artifactId>
<version>1.7.21version>
dependency>
<dependency>
<groupId>org.slf4jgroupId>
<artifactId>slf4j-apiartifactId>
<version>1.7.21version>
dependency>
<dependency>
<groupId>log4jgroupId>
<artifactId>log4jartifactId>
<version>1.2.17version>
dependency>
<dependency>
<groupId>org.apache.logging.log4jgroupId>
<artifactId>log4j-coreartifactId>
<version>2.5version>
dependency>
<dependency>
<groupId>org.apache.logging.log4jgroupId>
<artifactId>log4j-apiartifactId>
<version>2.5version>
dependency>
<dependency>
<groupId>org.javassistgroupId>
<artifactId>javassistartifactId>
<version>3.18.1-GAversion>
dependency>
<dependency>
<groupId>commons-logginggroupId>
<artifactId>commons-loggingartifactId>
<version>1.1.1version>
dependency>
<dependency>
<groupId>cglibgroupId>
<artifactId>cglibartifactId>
<version>2.2.2version>
dependency>
<dependency>
<groupId>asmgroupId>
<artifactId>asmartifactId>
<version>3.3.1version>
dependency>
dependencies>
project>
这就可以了,我这里实现了查,增,别的正在学习中。
写给自己:不开始永远不知道什么时候能结束