Preliminary use of MyBatis

MyBatis is a Java-based, open-source persistence layer Framework

First, the environment of MyBatis is built.

1. Download MyBatis https://github.com/mybatis/mybatis-3/releases

2. Import MyBatis-related packages into the project

Unzip the downloaded Mybatis-3.3.0.zip and open the folder

Import Mybatis-3.3.0.jar First

To all the jar packages in the Lib folder

Finally import the database connection-driven jar package (for example, I use MySQL to import Mysql-connector-java-5.1.7-bin.jar)

3. Configure the Log

Create a new configuration file named Log4j.properties under SRC

The code is as follows

Log4j.rootlogger=debug, Console #Console log4j.appender.console=org.apache.log4j.consoleappender Log4j.appender.console.layout=org.apache.log4j.patternlayout log4j.appender.console.layout.conversionpattern=%d [%t]%-5p [%c]-%m%n log4j.logger.java.sql.resultset=info log4j.logger.org.apache=info Log4j.logger.java.sql.Connect Ion=debug Log4j.logger.java.sql.statement=debug Log4j.logger.java.sql.preparedstatement=debug

Then create the Mybaisconfig.java configuration file

<?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" >       </transactionmanager>      <datasource type= "POOLED" >    //using connection pooling         <property name= "Driver"   Value= "com.mysql.jdbc.Driver"/>        <property name= "url"  value= "Jdbc:mysql://localhost:3306/dbname"/>        < Property name= "username"  value= "root"/>         <property name= "Password"  value= "root"/>       </datasource>    </environment>  </environments >  <mappers>    <mapper resource= "project/book/map/ Projectuser.xml "/>  </mappers></configuration>

Configure your database connection information, Driver,url,username,password the same as the JDBC Connection database configuration

The reference to the map file, in addition to the references in the code, can also

Absolute path Reference <mapper url= "File///var/sqlmap/authormapper.xml"/>

Package path Reference <package name= "Com.bao.mybatis.mapperinterface"/>

4. Create a MySQL database, build a table, enter a record, and then build the user class (including the set Get method) in the project

Create a User.xml file to write SQL statements

<mapper namespace= "/" > <select id= "FindByID" parametertype= "int" resulttype= "project.book.pojo.User" > SE Lect * from User where id=#{id} </select></mapper>

To create a test class

public static void Main (string[] args) {String resource = "Projtct/book/map/mybatisconfig.xml"; Reader reader = null; Sqlsession session;try {reader = Resources.getresourceasreader (Resource);} catch (IOException e) {e.printstacktrace ();} Sqlsessionfactory sqlmapper = new Sqlsessionfactorybuilder (). build (reader);//sqlsessionfactory is a program-oriented session  Sqlmapper.opensession (); Session is process-oriented, run out remember to call the Close method to close it jikeuser temp = Session.selectone ("FindByID", 1);//The first parameter is the ID of the previous code select, The second parameter is the corresponding idSystem.out.println (Temp.getusername ()) in the database table; System.out.println (Temp.getpassword ()); Session.close ();}

In this way, the first use of MyBatis program can be successfully run, welcome to point out the shortcomings, mutual exchange, thank you.

Preliminary use of MyBatis