【持久化框架MyBatis3一】MyBatis版HelloWorld
编程技术 / houtizong 发布于 3年前 106
MyBatis这个系列的文章，主要参考《Java Persistence with MyBatis 3》。
样例数据
本文以MySQL数据库为例，建立一个STUDENTS表，插入两条数据，然后进行单表的增删改查
CREATE TABLE STUDENTS(stud_id int(11) NOT NULL AUTO_INCREMENT,name varchar(50) NOT NULL,email varchar(50) NOT NULL,dob date DEFAULT NULL,PRIMARY KEY (stud_id)) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=UTF-8;/*Sample Data for the students table */insert into students(stud_id,name,email,dob)values (1,'Student1','[email protected]','1983-06-25');insert into students(stud_id,name,email,dob)values (2,'Student2','[email protected]','1983-06-25');
新建Maven项目，定义pom.xml
MyBatis Maven项目依赖
<dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.2</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.22</version> <scope>runtime</scope> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> <scope>runtime</scope> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> <scope>runtime</scope> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> </dependencies>
定义MyBatis的主配置文件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> <properties resource="config.properties"><!--定义配置信息，在本配置中可以使用${key}来引用--> <!--同名的key，config.properties覆盖property子元素的属性值--> <property name="name1" value="value.in.property.element"/> </properties> <typeAliases> <!--类型的别名: 用法,在resultType和parameterType可以使用别名，而不是全限定的类名--> <typeAlias alias="Student" type="com.mybatis3.domain.Student"/> <!--包名下的Model类，使用类名作为别名，不区分大小写--> <package name="com.mybatis3.domain"/> </typeAliases> <environments default="development"><!--默认的环境信息，在生产环境中需要修改production--> <environment id="development"><!--开发环境的配置--> <!--事务管理，MyBatis提供了两种方式，JDBC的连接事务管理以及Managed--> <transactionManager type="JDBC"/> <!--数据源配置--> <dataSource type="POOLED"> <property name="driver" value="${driver}"/> <property name="url" value="${url}"/> <property name="username" value="${username}"/> <property name="password" value="${password}"/> </dataSource> </environment> <environment id="production"><!--生产环境的配置--> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="${driver}"/> <property name="url" value="${url}"/> <property name="username" value="${username}"/> <property name="password" value="${password}"/> </dataSource> </environment> </environments> <mappers> <!--SQL映射文件，可以多个--> <mapper resource="StudentMapper.xml"/> </mappers></configuration>
定义SQL映射配置文件Students-Mapper.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"><mapper namespace="com.mybatis3.mappers.StudentMapper"> <!--namespace定义的Mapper可以作为Mapper接口--> <!--SQL列与POJO的字段的映射关系--> <resultMap type="Student" id="StudentResult"> <id property="studId" column="stud_id"/> <result property="name" column="name"/> <result property="email" column="email"/> <result property="dob" column="dob"/> </resultMap> <select id="findAllStudents" resultMap="StudentResult"> SELECT * FROM STUDENTS </select> <select id="findStudentById" parameterType="int" resultType="Student"> SELECT STUD_ID AS STUDID, NAME, EMAIL, DOB FROM STUDENTS WHERE STUD_ID=#{Id} </select> <insert id="insertStudent" parameterType="student"> INSERT INTO STUDENTS(STUD_ID,NAME,EMAIL,DOB) VALUES(#{studId },#{name},#{email},#{dob}) </insert></mapper>
定义主配置文件使用的config.properties
driver=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/testusername=rootpassword=rootkey=value.in.config.properties
定义Model
package com.mybatis3.domain;import java.util.Date;public class Student { private Long studId; private String name; private String email; private Date dob; public Long getStudId() { return studId; } public void setStudId(Long studId) { this.studId = studId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public Date getDob() { return dob; } public void setDob(Date dob) { this.dob = dob; }}
定义StudentMapper接口
package com.mybatis3.mappers;import com.mybatis3.domain.Student;import java.util.List;public interface StudentMapper { List<Student> findAllStudents(); Student findStudentById(Integer id); void insertStudent(Student student);}
定义StudentService
package com.mybatis3.serivces;import com.mybatis3.domain.Student;import com.mybatis3.mappers.StudentMapper;import com.mybatis3.util.MyBatisSqlSessionFactory;import org.apache.ibatis.session.SqlSession;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.util.List;public class StudentService { private Logger logger = LoggerFactory.getLogger(getClass()); public List<Student> findAllStudents() { SqlSession sqlSession = MyBatisSqlSessionFactory.openSession(); try { StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); return studentMapper.findAllStudents(); } finally { //If sqlSession is not closed then database Connection associated this sqlSession will not be //returned to pool and application may run out of connections. sqlSession.close(); } } public Student findStudentById(Integer studId) { logger.debug("Select Student By ID :{}", studId); SqlSession sqlSession = MyBatisSqlSessionFactory.openSession(); try { StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); return studentMapper.findStudentById(studId); } finally { sqlSession.close(); } } public Student findStudentById2(Integer studId) { logger.debug("Select Student By ID :{}", studId); SqlSession sqlSession = MyBatisSqlSessionFactory.openSession(); try { Student student = (Student) sqlSession. selectOne("com.mybatis3.mappers.StudentMapper.findStudentById", studId); return student; } finally { sqlSession.close(); } } public void createStudent(Student student) { SqlSession sqlSession = MyBatisSqlSessionFactory.openSession(); try { StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); studentMapper.insertStudent(student); sqlSession.commit(); } finally { sqlSession.close(); } }}
单元测试
package com.mybatis3.services;import com.mybatis3.domain.Student;import com.mybatis3.serivces.StudentService;import org.junit.AfterClass;import org.junit.Assert;import org.junit.BeforeClass;import org.junit.Test;import java.util.Date;import java.util.List;public class StudentServiceTest { private static StudentService studentService; @BeforeClass public static void setup() { studentService = new StudentService(); } @AfterClass public static void tearDown() { studentService = null; } @Test public void testFindAllStudents() { List<Student> students = studentService.findAllStudents(); Assert.assertNotNull(students); for (Student student : students) { System.out.println(student); } } @Test public void testFindStudentById() { Student student = studentService.findStudentById(1); Assert.assertNotNull(student); System.out.println(student); } @Test public void testCreateStudent() { Student student = new Student(); Long id = 1L; student.setStudId(id); student.setName("student_" + id); student.setEmail("student_" + id + "gmail.com"); student.setDob(new Date()); studentService.createStudent(student); Student newStudent = studentService.findStudentById(id.intValue()); Assert.assertNotNull(newStudent); }}
请勿发布不友善或者负能量的内容。与人为善，比聪明更重要！
技术博客集 - 网站简介：
前后端技术：
后端基于Hyperf2.1框架开发,前端使用Bootstrap可视化布局系统生成
网站主要作用：
1.编程技术分享及讨论交流，内置聊天系统;
2.测试交流框架问题，比如：Hyperf、Laravel、TP、beego;
3.本站数据是基于大数据采集等爬虫技术为基础助力分享知识，如有侵权请发邮件到站长邮箱，站长会尽快处理;
4.站长邮箱：[email protected];
文章归档
文章标签
友情链接
