Mybatis getting started

Required jar package: mybatis-3.x.x.jar, if you need to integrate with spring, also need to add the relevant package

1: do not care about the red color of the project directory.

2:Follow these steps:

1: Add a jar package

2: create a data source (configuration. XML) Create a database (omitted here)

<? 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> <! -- Create an alias for the object class user --> <typealias type = "com. Forum. Po. User" alias = "user"/> </typealiases> <! -- Configure the data source in MySQL database --> <environments 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/test "/> <property name =" username "value =" test "/> <property name =" password "value =" test "/> </datasource> </ environment> </environments> <mapper S> <! -- When usermapper. XML is loaded, the "Dao" implementation is loaded. --> <mapper resource = "mybatis/usermapper. xml"/> </mappers> </configuration>

3: Create object class user

Package COM. forum. po;/*** user class **/public class user extends entity {private string name; private integer age; Public String getname () {return name ;} public void setname (string name) {This. name = Name;} public integer getage () {return age;} public void setage (integer age) {This. age = age;} public user (){}}

4. Create the DaO interface, which can be called the Mapper interface: usermapper

package com.forum.dao;import com.forum.po.User;public interface UserMapper {public User findById(String Id);}

5: The implementation of creating Dao is different from the implementation of hibernarte here as an XML file, that is, usermapper. xml

<? XML version = "1.0" encoding = "UTF-8"?> <! Doctype mapper public "-// mybatis.org//dtd mapper 3.0 //" http://mybatis.org/dtd/mybatis-3-mapper.dtd "> <! -- The namespace equivalent to the DaO interface must be the same as the class path of the interface --> <mapper namespace = "com. Forum. Dao. usermapper"> <! -- The findbyid must be the same as the method name in the interface. Returning a user is the alias just now. If you do not get the alias, you need to write it together with the class path. --> <select id = "findbyid" parametertype = "hashmap" resulttype = "user"> select * From butone. student where ID =#{ ID} </SELECT> </mapper>

6: Test class, mybatistest

Package COM. forum. test; import Java. io. ioexception; import Org. apache. ibatis. io. resources; import Org. apache. ibatis. session. sqlsession; import Org. apache. ibatis. session. sqlsessionfactory; import Org. apache. ibatis. session. sqlsessionfactorybuilder; import COM. forum. dao. usermapper; import COM. forum. po. user;/*** mybatis database connection test ** @ author db2admin **/public class mybatistest {/*** get mybatis sqlsessionfacto Ry * sqlsessionfactory is responsible for creating sqlsession. Once created successfully, you can use the sqlsession instance to execute ing statements, commit, rollback, close, and other methods. * @ Return */Private Static sqlsessionfactory getsessionfactory () {sqlsessionfactory sessionfactory = NULL; string resource = "configuration. XML "; try {sessionfactory = new sqlsessionfactorybuilder (). build (resources. getresourceasreader (Resource);} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace ();} return sessionfactory;} public static void main (string [] ARGs) {sqlsession = getsessionfactory (). opensession (); usermapper = sqlsession. getmapper (usermapper. class); User user = usermapper. findbyid ("1"); system. out. println (user. getname ());}}

Mybatis getting started