Introduction and use basic framework

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Brief introduction

I. Introduction Framework

• Use angle: Semi-finished piece of software, only need to fill in some of our changes.
• Benefits: The code is built on experienced people to write code, high code quality, good readability.

Two, java web framework related

• Data storage: hibermate / mybatis
• MVC　   ：struts2 / spring mvc
• JavaSpript：jQuery

Third, tools

• spring produced STS, try using a lower version

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 MyBatis use

First, download the plug-jboss

• Click the help of the Eclipse Marketplace ... jboss input in the find, click go running, look for Red Hat CodeReady ..

 Second, the initial use of mybatis (manual)

1. New Java Project project, create a lib folder into which the package will mybatis jar.
2. Right-click on the jar package select Build Path, click Add to Build Path.
3. Because the need to connect to the database, the database should therefore jar package, the steps above.

Third, write a configuration file

 

• New Package in src, create named the mybatis-config.xml xml file. Mybatis be modified copied from the official documents in the configuration file, the code is as follows:

<?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" />
            <!--配置连接到数据库的必备信息-->
            <dataSource type="The POOLED " >
            <-! Tell the driver class -> 
                <Property name = " Driver " value = " com.mysql.jdbc.Driver " />
            <-! Connect to the database of the URL of -> 
                <Property name = " url " value = " jdbc: MySQL: // localhost: 3306 / Xcxy " />
             ! <- user name -> 
                <Property name = " username " value = " root " />
            ! <- password ->
                <property name="password" value="123456" />
            </dataSource>
        </environment>
    </environments>
 <!--resource后写Mapper的地址 -->
    <mappers>
        <mapper resource="cn/edu/xcu/mybatisdemo/UserMapper.xml" />
    </mappers>
</configuration> 

 

Fourth, write Mapper maps that write sql statement place

• Creating UserMapper.xml file, copied from the official document, the code is as follows:

<?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="cn.edu.xcu.mybatisdemo.UserMapper"> 　　　　-- namespace命名空间，解决重名问题
    <select id="selectUser" parameterType="int"        　　　　-- parameterType参数类型，resultType返回值类型
        resultType="cn.edu.xcu.mybatisdemo.User">
        select *from t_user where id = #{id}      　　　　　　　 --#{}是为了区分列名与传的参数
    </select>
</mapper> 

 

五、测试运行

public class MyBatisFind {
    public static void main(String[] args) throws IOException {
        //读取文件，连接到数据库
        String resource = "mybatis-config.xml";
        Reader reader = Resources.getResourceAsReader(resource);
        
        SqlSessionFactory sqlsessionfactory= new SqlSessionFactoryBuilder().build(reader);
        
        SqlSession sqlsession=sqlsessionfactory.openSession();
        //查询user
        User user=sqlsession.selectOne("cn.edu.xcu.mybatisdemo.UserMapper.selectUser",1);
        System.out.println(user);
        sqlsession.close();    
    }
}