MyBatis簡介
MyBatis 是一個可以自定義SQL、存儲過程和高級映射的持久層框架。MyBatis 摒除了大部分的JDBC代碼、手工設置參數和結果集重獲。MyBatis 只使用簡單的XML 和注解來配置和映射基本數據類型、Map 接口和POJO 到數據庫記錄。相對Hibernate和Apache OJB等“一站式”ORM解決方案而言,Mybatis 是一種“半自動化”的ORM實現。
需要使用的Jar包:mybatis-3.0.2.jar(mybatis核心包)。mybatis-spring-1.0.0.jar(與Spring結合包)。
下載地址:
http://ibatis.apache.org/tools/ibator
http://code.google.com/p/mybatis/
MyBatis+Spring+MySql簡單配置
搭建Spring環境
1,建立maven的web項目;
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,添加一個jsp頁面和對應的Controller;
6,測試。
建立MySql數據庫
建立一個學生選課管理數據庫。
表:學生表、班級表、教師表、課程表、學生選課表。
邏輯關系:每個學生有一個班級;每個班級對應一個班主任教師;每個教師只能當一個班的班主任;
使用下面的sql進行建數據庫,先建立學生表,插入數據(2條以上)。
更多sql請下載項目源文件,在resource/sql中。
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/* 建立數據庫 */ 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) ); /*插入學生數據*/ INSERT INTO STUDENT_TBL (STUDENT_ID, STUDENT_NAME, STUDENT_SEX, STUDENT_BIRTHDAY, CLASS_ID) VALUES (123456, '某某某' , '女' , '1980-08-01' , 121546 ) |
創建連接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環境
順序隨便,現在的順序是因為可以盡量的少的修改寫好的文件。
創建實體類: 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; } } |
創建數據訪問接口
Student類對應的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); } |
創建SQL映射語句文件
Student類的sql語句文件StudentMapper.xml
resultMap標簽:表字段與屬性的映射。
Select標簽:查詢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 > <!-- 查詢學生,根據id --> < select id = "getStudent" parameterType = "String" resultType = "StudentEntity" resultMap = "studentResultMap" > <![CDATA[ SELECT * from STUDENT_TBL ST WHERE ST.STUDENT_ID = #{studentID} ]]> </ select > <!-- 查詢學生列表 --> < select id = "getStudentAll" resultType = "commanagerdatamodelStudentEntity" resultMap = "studentResultMap" > <![CDATA[ SELECT * from STUDENT_TBL ]]> </ select > </ mapper > |
創建MyBatis的mapper配置文件
在src/main/resource中創建MyBatis配置文件:mybatis-config.xml。
typeAliases標簽:給類起一個別名。com.manager.data.model.StudentEntity類,可以使用StudentEntity代替。
Mappers標簽:加載MyBatis中實體類的SQL映射語句文件。
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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的制作工廠類的bean:SqlSessionFactoryBean,(在mybatis.spring包中)。需要指定配置文件位置和dataSource。
和數據訪問接口對應的實現bean。通過MapperFactoryBean創建出來。需要執行接口類全稱和SqlSession工廠bean的引用。
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<!-- 導入屬性配置文件 --> < 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 > |
也可以不定義mapper的bean,使用注解:
將StudentMapper加入注解
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@Repository @Transactional public interface StudentMapper { } |
對應的需要在dispatcher-servlet.xml中加入掃描:
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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 > |
測試StudentMapper
使用SpringMVC測試,創建一個TestController,配置tomcat,訪問index.do頁面進行測試:
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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測試:
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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()); } } } |