MyBatis初学
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MyBatis 初学笔记
Student.java
package com.xjh.domain;
import java.util.Date;
public class Student {
private Integer studId;
private String name;
private String email;
private Date dob;
public Integer getStudId() {
return studId;
}
public void setStudId(Integer 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;
}
}
StudentMapper.java
package com.xjh.mappers;
import java.util.List;
import org.apache.ibatis.session.RowBounds;
import com.xjh.domain.Student;
public interface StudentMapper {
List<Student> findAllStudents();
List<Student> findAllStudents(RowBounds rowBounds);
Student findStudentById(Integer id);
void insertStudent(Student student);
int deleteAllStudents();
int countAllStudents();
}
StudentMapper.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.xjh.mappers.StudentMapper">
<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>
<delete id="deleteAllStudents" parameterType="int">
delete from students
</delete>
<select id="countAllStudents" resultType="int">
select count(*) from students
</select>
</mapper>
StudentService.java
package com.xjh.services;
import java.util.List;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.xjh.domain.Student;
import com.xjh.mappers.StudentMapper;
import com.xjh.util.MyBatisSqlSessionFactory;
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 {
sqlSession.close();
}
}
/**
* 采用分页的方式来查询
*/
public List<Student> findAllStudents2() {
int offset = 0, limit = 10;
RowBounds rowBounds = new RowBounds(offset, limit);
SqlSession sqlSession = MyBatisSqlSessionFactory.openSession();
try {
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
return studentMapper.findAllStudents(rowBounds);
} finally {
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) {
SqlSession sqlSession = MyBatisSqlSessionFactory.openSession();
try {
Student student = (Student) sqlSession.selectOne("com.xjh.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();
}
}
public int deleteAllStudents() {
SqlSession sqlSession = MyBatisSqlSessionFactory.openSession();
try {
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
int i = studentMapper.deleteAllStudents();
sqlSession.commit();
return i;
} finally {
sqlSession.close();
}
}
public int countAllStudents() {
SqlSession sqlSession = MyBatisSqlSessionFactory.openSession();
try {
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
int i = studentMapper.countAllStudents();
return i;
} finally {
sqlSession.close();
}
}
}
StudentServiceTest.java
package com.xjh.services;
import java.util.Date;
import java.util.List;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
import com.xjh.domain.Student;
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 testCreateStudent() {
for (int i = 1; i <= 100; i++) {
Student student = new Student();
int id = i;
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);
Assert.assertNotNull(newStudent);
}
}
@Test
public void testFindAllStudents() {
List<Student> students = studentService.findAllStudents();
Assert.assertNotNull(students);
for (Student student : students) {
System.out.println(student);
}
}
@Test
public void testFindAllStudents2() {
List<Student> students = studentService.findAllStudents2();
Assert.assertNotNull(students);
for (Student student : students) {
System.out.println("......" + student.getName());
}
}
@Test
public void testFindStudentById() {
Student student = studentService.findStudentById(1);
Assert.assertNotNull(student);
System.out.println(student);
}
@Test
public void testFindStudentById2() {
Student student = studentService.findStudentById2(1);
Assert.assertNotNull(student);
System.out.println(student);
}
@Test
public void testDeleteAllStudents() {
int begin = studentService.countAllStudents();
int end = studentService.deleteAllStudents();
Assert.assertEquals(end, begin);
System.out.println("begin: " + begin + " end: " + end);
}
// create table students(stud_id int(11) not null auto_increment, name varch
// ar(50) not null, email varchar(50) not null, dob date default null, primary key
// (stud_id));
}
MyBatisSqlSessionFactory.java
package com.xjh.util;
import java.io.IOException;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class MyBatisSqlSessionFactory {
private static SqlSessionFactory sqlSessionFactory;
public static SqlSessionFactory getSqlSessionFactory() {
if (sqlSessionFactory == null) {
InputStream inputStream;
try {
inputStream = Resources.getResourceAsStream("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
throw new RuntimeException(e.getCause());
}
}
return sqlSessionFactory;
}
public static SqlSession openSession() {
return getSqlSessionFactory().openSession();
}
}
MyBatisUtil.java
package com.xjh.util;
import org.apache.ibatis.session.SqlSession;
public class MyBatisUtil {
public static SqlSession openSession() {
return MyBatisSqlSessionFactory.openSession();
}
}
log4j.properties
log4j.rootLogger=DEBUG, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d [%-5p] %c - %m%n
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>
<typeAliases>
<typeAlias alias="Student" type="com.xjh.domain.Student"/></typeAliases>
<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="root"/>
<property name="password" value="123456abcd"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/xjh/mappers/StudentMapper.xml"/>
</mappers>
</configuration>
需要引入的包
<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>
数据库建表语句
create table students(stud_id int(11) not null auto_increment, name varch
ar(50) not null, email varchar(50) not null, dob date default null, primary key
(stud_id));
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