MyBatis Getting Started (ii)--Accessing the database by means of an interface

First, establish the interface Usermapper.java

publicinterface UserMapper {    publicgetAllUser();    publicgetUserById(String userId);    publicintinsert(User user);    publicintupdate(User user);    publicintdelete(User user);}

Two modifications Usermapper.xml

<?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="Com.elements.user.mapper.UserMapper">Note that this differs from the original way here must and your interface path + name has been (excluding. Java)<resultmap type="Com.elements.user.model.User" id="UserMap" >        <ID Column="userid" property ="userid"/>        <result column= "UserName" property ="UserName"/>        <result column= "useremail" property ="UserEmail"/>     </resultmap>    <select id="Getalluser" resultmap="UserMap"> SELECT * FROM Mybatis.user</Select>    <select id="Getuserbyid" resultmap="UserMap"  ParameterType="String">SELECT * from Mybatis.user where userid= #{userid}</Select>    <insert id="Insert" parametertype=" Com.elements.user.model.User ">Insert into Mybatis.user (UserName, UserEmail) VALUES (#{username}, #{useremail})</Insert>    <update id="Update" parametertype="Com.elements.user.model.User" >Update Mybatis.user set Username=#{username}, Useremail=#{useremail} where userid= #{userid}</Update>    <delete id="Delete" parametertype="String"> Delete mybatis.user where userid= #{userid}</Delete></mapper>

Three, mybatis-config.xml configuration

This becomes the class of the interface

<?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>    <properties Resource="jdbc.properties" />    <environments Default="Dev">        <environment ID="Dev">            <transactionmanager type="JDBC" />            <dataSource type="Pooled">                < property name="Driver" value="${driver}" />                 < property name="url" value="${url}" />                < property name="username" value="${username}" />                < property name="password" value="${password}" / >            </dataSource>        </Environment>    </environments>    <mappers>        <mapper class="Com.elements.user.mapper.UserMapper"/>    </mappers></configuration>

Iv. Test class

public  class  TestUser {@Test public  void   Testselectall  () throws IOException {String resource =  "Mybatis-config.xml"  ; InputStream InputStream = resources.getresourceasstream (Resource); Sqlsessionfactory sqlsessionfactory = new  Sqlsessionfactorybuilder (). Bui LD (InputStream); sqlsession session = Sqlsessionfactory.opensession (); try  {Usermapper user = (Usermapper) session.getmapper (Usermapper.class); List<user> userlist = User.getalluser (); System. out . Print (userlist); } finally  {session.close (); } }}

Project code Download: Http://pan.baidu.com/s/1c12EDaC

Five, not mybatis-config.xml configuration mode

 Public classTestUser {@Test Public void Testselectall() throws IOException {String resource ="Mybatis-config.xml";        InputStream InputStream = resources.getresourceasstream (Resource); Sqlsessionfactory sqlsessionfactory =NewSqlsessionfactorybuilder (). Build (InputStream); sqlsession session = Sqlsessionfactory.opensession ();if(!session.getconfiguration (). Getmapperregistry (). Hasmapper (Usermapper.class)) session.getconfiguration (). AddMap Per (Usermapper.class);//Get the session configuration file here and see if our interface is registered in Mapperregistry        //Add our interface if not registered        Try{Usermapper user = (Usermapper) session.getmapper (Usermapper.class);            List<user> userlist = User.getalluser (); System. out. print (userlist); }finally{Session.close (); }    }}

Project code Download: Http://pan.baidu.com/s/1slBrQ0X

MyBatis Getting Started (ii)--Accessing the database by means of an interface