Mybatis+mysql Getting Started with

First, Introduction

MyBatis is an excellent persistence layer framework that supports custom SQL, stored procedures, and advanced mapping.

Second, the introduction of the use

1. Add dependencies

A, use MAVEN to manage dependencies, take the version I used this time as an example

    <dependencies>        <dependency>            <groupId>junit</groupId>            <artifactId> junit</artifactid>            <version>4.12</version>            <scope>test</scope>        </dependency>        <dependency>            <groupId>org.mybatis</groupId>            < Artifactid>mybatis</artifactid>            <version>3.2.  3</version>        </dependency>        <dependency>            <groupid>mysql</groupid >            <artifactId>mysql-connector-java</artifactId>            <version>5.1.  </version>        </dependency>    </dependencies>

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B. You can also use Gradle to manage dependencies

Dependencies {    'junit' 'junit '  4.12 'org.mybatis:mybatis:3.2.3'           'mysql:mysql-connector-java:5.1.38'}

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C, can also go to the official website to download, official address: http://www.mybatis.org/mybatis-3/

2. Initialize database and initial data, take database moy_mybatis and table t_test as an example

# # CREATE DATABASE    moy_mybatis;## create a test table created table t_test (    ID INT (one) auto_increment,     ' creation time '    , ' Modified time ', Content    VARCHAR (COMMENT ' content '),    PRIMARY KEY (id));

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3. New Entity class Testentity

 Packagecom.moy.mybatis3.entity;Importjava.util.Date;/*** [Project]:moy-gradle-project <br/> * [email]:[email protected] <br/> * [DATE]:2018/2/20 <br/> * [Description]: <br/> * *@authorYexiangyang*/ Public classtestentity {PrivateInteger ID; PrivateDate Createtime; PrivateDate Modifytime; PrivateString content;  PublicInteger getId () {returnID; }     Public voidsetId (Integer id) { This. ID =ID; }     PublicDate Getcreatetime () {returnCreatetime; }     Public voidsetcreatetime (Date createtime) { This. Createtime =Createtime; }     PublicDate Getmodifytime () {returnModifytime; }     Public voidsetmodifytime (Date modifytime) { This. Modifytime =Modifytime; }     PublicString getcontent () {returncontent; }     Public voidsetcontent (String content) { This. Content =content; } @Override PublicString toString () {return"testentity{" + "id=" + ID + ", createtime=" + Createtime + ", modifytime=" + Modifytime + ", content= '" + content + ' \ ' + '} '; }}

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4. New Interface Testmapper

 PackageCom.moy.mybatis3.mapper;Importcom.moy.mybatis3.entity.TestEntity;Importjava.io.Serializable;Importjava.util.List;/*** [Project]:moy-gradle-project <br/> * [email]:[email protected] <br/> * [DATE]:2018/2/20 <br/> * [Description]: <br/> * *@authorYexiangyang*/ Public InterfaceTestmapper {List<TestEntity>list ();    Testentity get (Serializable ID); intInsert (testentity testentity); intUpdate (testentity testentity); intDelete (Serializable ID); intcount ();}

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5. New Entity Mapping file Test.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" ><map Per namespace= "Com.moy.mybatis3.mapper.TestMapper" > <select id= "list" resulttype= "Testentity" >SELECT*From t_test</select> <select id= "Count" resulttype= "int" >SELECT Count (*) from T_test</select> <select id= "get" parametertype= "int" resulttype= "testentity" >SELECT Id,create_time as createtime,modify_time as Modifytime, content from T_test WHERE ID=#{id}</select> <insert id= "Insert" parametertype= "testentity" >INSERT into T_test (create_time,modify_time,content) VALUES (#{createtime},#{modifytime},#{content}) </insert> <update id= "Update" parametertype= "Testentity" >UPDATE t_test SET modify_time=#{modifytime},content=#{content} WHERE ID=#{id}</update> <delete id= "delete" parametertype= "int" >DELETE from t_test WHERE ID=#{id}</delete></mapper>

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6. New MyBatis configuration information file Mybatis-config.xml

<?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> < Typealiases> <!--project entity classes corresponding package names--< PackageName= "Com.moy.mybatis3.entity"/> </typeAliases> <!--MYQL database connection information--<environmentsdefault= "Development" > <environment id= "Development" > <transactionmanager type= "JDBC"/>                <datasource type= "Pooled" > <property name= "Driver" value= "Com.mysql.jdbc.Driver"/> <property name= "url" value= "Jdbc:mysql://127.0.0.1:3306/moy_mybatis?usessl=false"/> <propert Y name= "username" value= "root"/> <property name= "password" value= "123"/> </datasourc E> </environment> </environments> <!--configuring entity mapping XML Paths--<mappers> <mappe R resource= "Mapper/test.xml" ></mapper> </mappers></configuration>

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7, for the convenience of testing, to write a tool to obtain sqlsession class Mybatis3utils

 Packagecom.moy.mybatis3.utils;Importorg.apache.ibatis.io.Resources;Importorg.apache.ibatis.session.SqlSession;Importorg.apache.ibatis.session.SqlSessionFactory;ImportOrg.apache.ibatis.session.SqlSessionFactoryBuilder;Importjava.io.IOException;ImportJava.io.Reader;Importjava.util.Objects;/*** [Project]:moy-gradle-project <br/> * [email]:[email protected] <br/> * [Date]:2018/2/19 <br/> * [Description]: <br/> * *@authorYexiangyang*/ Public Abstract classMybatis3utils { Public Static Finalsqlsessionfactory sqlsessionfactory;  Public Static FinalThreadlocal<sqlsession> Sessionthread =NewThreadlocal<>(); Static {        Try{Reader Reader= Resources.getresourceasreader ("Mybatis-config.xml"); Sqlsessionfactory=NewSqlsessionfactorybuilder (). build (reader); } Catch(IOException e) {Throw NewRuntimeException (e); }    }     Public Staticsqlsession getcurrentsqlsession () {sqlsession sqlsession=Sessionthread.get (); if(Objects.isnull (sqlsession)) {sqlsession=sqlsessionfactory.opensession ();        Sessionthread.set (sqlsession); }        returnsqlsession; }     Public Static voidclosecurrentsession () {sqlsession sqlsession=Sessionthread.get (); if(Objects.nonnull (sqlsession)) {sqlsession.close (); } sessionthread.set (NULL); }}

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8, new test class Testmappertest test

 PackageCom.moy.mybatis3.mapper;Importcom.moy.mybatis3.entity.TestEntity;Importcom.moy.mybatis3.utils.Mybatis3Utils;Importorg.apache.ibatis.session.SqlSession;ImportOrg.junit.After;ImportOrg.junit.Before;Importorg.junit.Test;Importjava.util.Arrays;Importjava.util.Date;Importjava.util.List;Import Staticorg.junit.assert.*;/*** [Project]:moy-gradle-project <br/> * [email]:[email protected] <br/> * [DATE]:2018/2/20 <br/> * [Description]: <br/> * *@authorYexiangyang*/ Public classtestmappertest {sqlsession sqlsession;    Testmapper Testmapper; @Before Public voidbefore () {sqlsession=mybatis3utils.getcurrentsqlsession (); Testmapper= Sqlsession.getmapper (testmapper.class); } @After Public voidAfter () {mybatis3utils.closecurrentsession (); } @Test Public voidInsert () {testentity entity=Newtestentity (); Entity.setcreatetime (NewDate ()); Entity.setmodifytime (NewDate ()); Entity.setcontent ("I am Content");        System.out.println (Testmapper.insert (entity));    Sqlsession.commit (); } @Test Public voidcount () {System.out.println (Testmapper.count ()); } @Test Public voidlist () {list<TestEntity> list =testmapper.list ();    System.out.println (Arrays.tostring (List.toarray ())); } @Test Public voidget () {System.out.println (Testmapper.get (1)); } @Test Public voidUpdate () {testentity entity=Newtestentity (); Entity.setid (1); Entity.setmodifytime (NewDate ()); Entity.setcontent ("I am the modified content");        Testmapper.update (entity);    Sqlsession.commit (); } @Test Public voidDelete () {Testmapper.delete (1);    Sqlsession.commit (); }}

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Yexiangyang

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Mybatis+mysql Getting Started with