MyBatis (1)

Jar package required: mybatis-3.x.x.jar, assuming the need to integrate with spring, also need to increase the relevant package

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

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 BD2 database --> <environments default = "development"> <environment id = "development"> <transactionManager type = "jdbc"/> <dataSource type = "POOLED "> <property name =" driver "value =" com. ibm. db2.jcc. DB2Driver "/> <property name =" url "value =" jdbc: db2: // localhost: 50000/forum "/> <property name =" username "value =" DB2ADMIN "/> <property name =" password "value =" admin "/> </dataSource> </ environment> </environments> <Mappers> <! -- 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 ** @ author db2admin **/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 dao interface, which can be called 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 and return a User, which is the alias just now. If the alias is not used, it is difficult to write the class path together. --> <select id = "findById" parameterType = "HashMap" resultType = "User"> select * from butone. student where id =#{ id} </select> </mapper>

6: Benchmark 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 retry *** @ 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 run 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 sqlSession = getSessionFactory (). openSession (); UserMapper userMapper = sqlSession. getMapper (UserMapper. class); User user = userMapper. findById ("1"); System. out. println (user. getName ());}}

MyBatis (1)