MyBatis简介
MyBatis 是一个可以自定义SQL、存储过程和高级映射的持久层框架。MyBatis 摒除了大部分的JDBC代码、手工设置参数和结果集重获。MyBatis 只使用简单的XML 和注解来配置和映射基本数据类型、Map 接口和POJO 到数据库记录。相对Hibernate和Apache OJB等“一站式”ORM解决方案而言,Mybatis 是一种“半自动化”的ORM实现。
需要使用的Jar包:mybatis-3.0.2.jar(mybatis核心包)。mybatis-spring-1.0.0.jar(与Spring结合包)。
下载地址:
http://ibatis.apache.org/tools/ibator
http://code.google.com/p/mybatis/
MyBatis+Spring+MySql简单配置
搭建Spring环境
1,建立maven的web项目;
2,加入Spring框架、配置文件;
3,在pom.xml中加入所需要的jar包(spring框架的、mybatis、mybatis-spring、junit等);
4,更改web.xml和spring的配置文件;
5,添加一个jsp页面和对应的Controller;
6,测试。
建立MySql数据库
建立一个学生选课管理数据库。
表:学生表、班级表、教师表、课程表、学生选课表。
逻辑关系:每个学生有一个班级;每个班级对应一个班主任教师;每个教师只能当一个班的班主任;
使用下面的sql进行建数据库,先建立学生表,插入数据(2条以上)。
更多sql请下载项目源文件,在resource/sql中。
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/* 建立数据库 */ CREATE DATABASE STUDENT_MANAGER; USE STUDENT_MANAGER; /***** 建立student表 *****/ CREATE TABLE STUDENT_TBL ( STUDENT_ID VARCHAR (255) PRIMARY KEY , STUDENT_NAME VARCHAR (10) NOT NULL , STUDENT_SEX VARCHAR (10), STUDENT_BIRTHDAY DATE , CLASS_ID VARCHAR (255) ); /*插入学生数据*/ INSERT INTO STUDENT_TBL (STUDENT_ID, STUDENT_NAME, STUDENT_SEX, STUDENT_BIRTHDAY, CLASS_ID) VALUES (123456, '某某某' , '女' , '1980-08-01' , 121546 ) |
创建连接MySql使用的配置文件mysql.properties。
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jdbc.driverClassName=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/student_manager?user=root&password=bjpowernode&useUnicode=true&characterEncoding=UTF-8 |
搭建MyBatis环境
顺序随便,现在的顺序是因为可以尽量的少的修改写好的文件。
创建实体类: StudentEntity
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public class StudentEntity implements Serializable { private static final long serialVersionUID = 3096154202413606831L; private ClassEntity classEntity; private Date studentBirthday; private String studentID; private String studentName; private String studentSex; public ClassEntity getClassEntity() { return classEntity; } public Date getStudentBirthday() { return studentBirthday; } public String getStudentID() { return studentID; } public String getStudentName() { return studentName; } public String getStudentSex() { return studentSex; } public void setClassEntity(ClassEntity classEntity) { this .classEntity = classEntity; } public void setStudentBirthday(Date studentBirthday) { this .studentBirthday = studentBirthday; } public void setStudentID(String studentID) { this .studentID = studentID; } public void setStudentName(String studentName) { this .studentName = studentName; } public void setStudentSex(String studentSex) { this .studentSex = studentSex; } } |
创建数据访问接口
Student类对应的dao接口:StudentMapper。
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public interface StudentMapper { public StudentEntity getStudent(String studentID); public StudentEntity getStudentAndClass(String studentID); public List<StudentEntity> getStudentAll(); public void insertStudent(StudentEntity entity); public void deleteStudent(StudentEntity entity); public void updateStudent(StudentEntity entity); } |
创建SQL映射语句文件
Student类的sql语句文件StudentMapper.xml
resultMap标签:表字段与属性的映射。
Select标签:查询sql。
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<? 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.manager.data.StudentMapper" > < resultMap type = "StudentEntity" id = "studentResultMap" > < id property = "studentID" column = "STUDENT_ID" /> < result property = "studentName" column = "STUDENT_NAME" /> < result property = "studentSex" column = "STUDENT_SEX" /> < result property = "studentBirthday" column = "STUDENT_BIRTHDAY" /> </ resultMap > <!-- 查询学生,根据id --> < select id = "getStudent" parameterType = "String" resultType = "StudentEntity" resultMap = "studentResultMap" > <![CDATA[ SELECT * from STUDENT_TBL ST WHERE ST.STUDENT_ID = #{studentID} ]]> </ select > <!-- 查询学生列表 --> < select id = "getStudentAll" resultType = "commanagerdatamodelStudentEntity" resultMap = "studentResultMap" > <![CDATA[ SELECT * from STUDENT_TBL ]]> </ select > </ mapper > |
创建MyBatis的mapper配置文件
在src/main/resource中创建MyBatis配置文件:mybatis-config.xml。
typeAliases标签:给类起一个别名。com.manager.data.model.StudentEntity类,可以使用StudentEntity代替。
Mappers标签:加载MyBatis中实体类的SQL映射语句文件。
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<? 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 > < typeAlias alias = "StudentEntity" type = "com.manager.data.model.StudentEntity" /> </ typeAliases > < mappers > < mapper resource = "com/manager/data/maps/StudentMapper.xml" /> </ mappers > </ configuration > |
修改Spring 的配置文件
主要是添加SqlSession的制作工厂类的bean:SqlSessionFactoryBean,(在mybatis.spring包中)。需要指定配置文件位置和dataSource。
和数据访问接口对应的实现bean。通过MapperFactoryBean创建出来。需要执行接口类全称和SqlSession工厂bean的引用。
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<!-- 导入属性配置文件 --> < context:property-placeholder location = "classpath:mysql.properties" /> < bean id = "dataSource" class = "org.springframework.jdbc.datasource.DriverManagerDataSource" > < property name = "driverClassName" value = "${jdbc.driverClassName}" /> < property name = "url" value = "${jdbc.url}" /> </ bean > < bean id = "transactionManager" class = "org.springframework.jdbc.datasource.DataSourceTransactionManager" > < property name = "dataSource" ref = "dataSource" /> </ bean > < bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean" > < property name = "configLocation" value = "classpath:mybatis-config.xml" /> < property name = "dataSource" ref = "dataSource" /> </ bean > <!— mapper bean --> < bean id = "studentMapper" class = "org.mybatis.spring.MapperFactoryBean" > < property name = "mapperInterface" value = "com.manager.data.StudentMapper" /> < property name = "sqlSessionFactory" ref = "sqlSessionFactory" /> </ bean > |
也可以不定义mapper的bean,使用注解:
将StudentMapper加入注解
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@Repository @Transactional public interface StudentMapper { } |
对应的需要在dispatcher-servlet.xml中加入扫描:
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< bean class = "org.mybatis.spring.mapper.MapperScannerConfigurer" > < property name = "annotationClass" value = "org.springframework.stereotype.Repository" /> < property name = "basePackage" value = "comlimingmanager" /> < property name = "sqlSessionFactory" ref = "sqlSessionFactory" /> </ bean > |
测试StudentMapper
使用SpringMVC测试,创建一个TestController,配置tomcat,访问index.do页面进行测试:
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@Controller public class TestController { @Autowired private StudentMapper studentMapper; @RequestMapping (value = "index.do" ) public void indexPage() { StudentEntity entity = studentMappergetStudent( "10000013" ); System.out.println( "name:" + entity.getStudentName()); } } |
使用Junit测试:
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@RunWith (value = SpringJUnit4ClassRunner. class ) @ContextConfiguration (value = "test-servletxml" ) public class StudentMapperTest { @Autowired private ClassMapper classMapper; @Autowired private StudentMapper studentMapper; @Transactional public void getStudentTest(){ StudentEntity entity = studentMapper.getStudent( "10000013" ); System.out.println( "" + entity.getStudentID() + entity.getStudentName()); List<StudentEntity> studentList = studentMapper.getStudentAll(); for ( StudentEntity entityTemp : studentList){ System.out.println(entityTemp.getStudentName()); } } } |