Idea下使用maven搭建SSM(二):MyBatis
開發Web應用,資料的儲存和處理往往離不開資料庫和SQL語句。在使用Java開發的Web應用中,自然也少不了連線資料庫的步驟。在底層連線資料庫的時候,一般優勝JDBC技術,也就是Java的一種提供資料庫連線和操作SQL的底層API。但是網際網路技術正在飛速發展,使用原始JDBC已經滿足不了專案的開發需求了,這就使得Hibernate,MyBatis(iBatis),JPA,JDO等一些優秀的ORM框架誕生,它們不公結合了原生JDBC的功能,還使開發簡捷化,規範化。
前一章我講了使用maven在idea下搭建SpringMVC,下面接著講使用maven在idea下搭建MyBatis。
首先在mysql中建立一個名為test的資料庫,然後在資料庫中建立表“userinfo”:
1,開啟之前專案,pom.xm中加入MyBatis的引用:
<dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.12</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.20</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.41</version> </dependency> <dependency> <groupId>com.microsoft.sqlserver</groupId> <artifactId>sqljdbc4</artifactId> <version>4.0</version> </dependency>
2,在Java資料夾下建立包"cn.com.mybatis.pojo",在包下建立java類"UserInfo":
package cn.com.mybatis.pojo; import java.io.Serializable; public class UserInfo implements Serializable { private int id; 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; } private String userName; public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } private String password; private int age; public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
2,在"resource"資料夾下新建一個"mybatis"資料夾,
編寫SQL對映檔案:
在mybatis資料夾加新建一個mapper資料夾,並在mapper下建立名為userinfo的xml檔案,編輯如下:
<?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="test">
<select id="findById" parameterType="int" resultType="cn.com.mybatis.pojo.UserInfo">
SELECT * FROM userinfo WHERE id=#{id}
</select>
</mapper>
在"mybatis"資料夾下新建名為"SqlMapConfig"的xml檔案,並編輯:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTDConfig 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"></transactionManager>
<dataSource type="POOLED">
<property name="drever" value="org.gjt.mm.mysql.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/test?characterEncoding=utf-8"></property>
<property name="username" value="root"></property>
<property name="password" value="123456"></property>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mybatis/mapper/userinfo.xml"></mapper>
</mappers>
</configuration>
3,在Java資料夾下建立包"cn.com.mybatis.datasource",在包下建立並編寫資料庫互動類(DataConnection):
package cn.com.mybatis.datasource;
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 DataConnection {
private String resource="mybatis/SqlMapConfig.xml";
private SqlSessionFactory sqlSessionFactory;
private SqlSession sqlSession;
public SqlSession getSqlSession() throws IOException{
InputStream inputStream= Resources.getResourceAsStream(resource);
sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
sqlSession=sqlSessionFactory.openSession();
return sqlSession;
}
}
在Java資料夾下建立包"cn.com.mybatis.dao",在包下建立並編寫資料庫訪問類(UserInfoDAO):
package cn.com.mybatis.dao;
import cn.com.mybatis.datasource.DataConnection;
import cn.com.mybatis.pojo.UserInfo;
import org.apache.ibatis.session.SqlSession;
import java.io.IOException;
public class UserInfoDAO {
public DataConnection dataConn = new DataConnection();
public UserInfo GetUserById() throws IOException{
SqlSession sqlSession=dataConn.getSqlSession();
UserInfo user = sqlSession.selectOne("test.findById",1);
sqlSession.close();
return user;
}
}
最後,在表現層顯示資料:
修改src/main/webapp/Java/cn.com.controller/Home
package cn.com.controller;
import cn.com.mybatis.dao.UserInfoDAO;
import cn.com.mybatis.pojo.UserInfo;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import java.io.IOException;
@Controller
@RequestMapping("/Home")
public class Home {
@RequestMapping("/Index")
public ModelAndView Index() throws IOException {
ModelAndView view = new ModelAndView();
UserInfoDAO userInfoDTO=new UserInfoDAO();
UserInfo user = userInfoDTO.GetUserById();
view.addObject("userInfo",user);
view.setViewName("Index");
return view;
}
}
修改Index.JSP檔案
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2018-12-07
Time: 16:52
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h2>Index</h2>
<ul>
<li>${userInfo.id}</li>
<li>${userInfo.userName}</li>
<li>${userInfo.age}</li>
</ul>
</body>
</html>
大功告成!
執行Tomcat
目錄結構: