Java data Access (3): MyBatis

Maven

        <!--import MySQL database link jar--        <dependency>            <groupId>mysql</groupId>            < artifactid>mysql-connector-java</artifactid>            <version>5.1.6</version>        </ Dependency>        <!--import MyBatis Package--        <dependency>            <groupid>org.mybatis</groupid >            <artifactId>mybatis</artifactId>            <version>3.1.1</version>        </ Dependency>

Mybatis-config.xml 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>    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/test2 "/>                < Property name= "username" value= "root"/>                <property name= "password" value= "sa1234$"/>            </ datasource>        </environment>    </environments>    <mappers>        <mapper Resource= "Userdaomapper.xml"/>    </mappers></configuration>

Create an entity class

 PackageMy.pojo; Public classUser {Private intuserId; PrivateString UserName; PrivateString password; PrivateString Comment;  Public intgetUserId () {returnuserId; }         Public voidSetuserid (intuserId) {         This. UserId =userId; }           PublicString GetUserName () {returnUserName; }     Public voidsetusername (String userName) { This. UserName =UserName; }             PublicString GetPassword () {returnpassword; }     Public voidSetPassword (String password) { This. Password =password; }             PublicString getcomment () {returncomment; }     Public voidsetcomment (String comment) { This. Comment =comment; }}

Create a mapping file

<?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= "My.dao.UserDao" > <insert id= "Insert" parametertype= "My.pojo.User" >INSERT INTO User (Username,password,comment) VALUES (#{username},#{password},#{comment})</insert> <update id= "Update" parametertype= "My.pojo.User" >Update user Set UserName=#{username},password=#{password},comment=#{comment} where UserName=#{username}</update> <delete id= "delete" parametertype= "int" >Delete from user where UserName=#{username}</delete> <select id= "Findbyusername" parametertype= "String" resulttype= "My.pojo.User" >Select* FROM user where username=#{username}</select> <select id= "Countall" resulttype= "int" >Select COUNT (*) c from user; </select> <select id= "SelectAll" resulttype= "My.pojo.User" >Select*From the user order by userName ASC</select> <select id= "FindByID" parametertype= "Int" resulttype= "My.pojo.User" >Select*From user where userId=#{userid}</select></mapper>

Create DAO

 PackageMy.dao;Importjava.util.List;ImportMy.pojo.User; Public InterfaceUserdao { Public intInsert (user user);  Public intUpdate (user user);  Public intDelete (String userName);  PublicList<user>SelectAll ();  Public intCountall ();  PublicUser findbyusername (String userName);  PublicUser FindByID (intuserId);}

Test

 PackageMy.common;Importjava.io.IOException;ImportJava.io.Reader;Importorg.apache.ibatis.io.Resources;Importorg.apache.ibatis.session.SqlSession;Importorg.apache.ibatis.session.SqlSessionFactory;ImportOrg.apache.ibatis.session.SqlSessionFactoryBuilder; Public classSessionhelper {StaticSqlsessionfactory Factory;  Public StaticSqlsession getsession ()throwsIOException {if(Factory = =NULL) {Reader Reader= Resources.getresourceasreader ("Mybatis-config.xml"); Factory=NewSqlsessionfactorybuilder (). build (reader); } sqlsession Session=factory.opensession (); returnsession; }}

 PackageMy.main;ImportMy.dao.UserDao;ImportMy.pojo.User;Importorg.apache.ibatis.session.SqlSession;Importmy.common.*; Public classApp { Public Static voidMain (string[] args) {sqlsession session=NULL; Try{Session=sessionhelper.getsession (); Userdao Userdao= Session.getmapper (Userdao.class); User User= Userdao.findbyid (18);            System.out.println (User.getusername ());        Session.commit (); } Catch(Exception e) {e.printstacktrace ();        Session.rollback (); } finally {            if(Session! =NULL) {session.close (); }        }    }}

Java data Access (3): MyBatis