创建一个空的Maven项目,删去src,用作存储pom的父项目
pom中存放下列依赖:
org.mybatis
mybatis
3.5.11
mysql
mysql-connector-java
5.1.46
创建Module在pom中加入测试依赖
junit
junit
4.13.2
test
创建数据库
CREATE TABLE student(
stuID INTEGER NOT NULL,
stuName VARCHAR(20),
stuSalary DECIMAL(10,3)
)
创建实体类
package su.Entity;
/**
* @author haustsusu
* @create 2023-09-08-19:12
*/
public class Student {
private Integer stuId;
private String stuName;
private Double stuSalary;
public Student() {
}
public Student(Integer stuId, String stuName, Double stuSalary) {
this.stuId = stuId;
this.stuName = stuName;
this.stuSalary = stuSalary;
}
public Integer getStuId() {
return stuId;
}
public void setStuId(Integer stuId) {
this.stuId = stuId;
}
public String getStuName() {
return stuName;
}
public void setStuName(String stuName) {
this.stuName = stuName;
}
public Double getStuSalary() {
return stuSalary;
}
public void setStuSalary(Double stuSalary) {
this.stuSalary = stuSalary;
}
@Override
public String toString() {
return "Student{" +
"stuId=" + stuId +
", stuName='" + stuName + '\'' +
", stuSalary=" + stuSalary +
'}';
}
}
创建Mybatis框架需要创建Mapper.xml,Mapper接口,MybatisConfig配置文件
Mapper接口
public interface stuMapper {
List QueryStudents();
Student QueryStudent(Integer Id);
}
Mybatis配置文件
最后在测试类中运行
public class StudentTest {
@Test
public void test01() throws IOException {
//1.读取外部配置文件,获取一个输入流
InputStream resourceAsStream = Resources.getResourceAsStream("MybatisConfig.xml");
//2.创建sqlSessionFactory对象
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
//3.获取Sqlsession对象[自动开启JDBC]
SqlSession sqlSession = sqlSessionFactory.openSession();
//4.获取代理mapper对象
stuMapper mapper = sqlSession.getMapper(stuMapper.class);
//执行查询所有学生的方法
List students = (List) mapper.QueryStudents();
//查询id学生的方法
Student student = mapper.QueryStudent(10001);
System.out.println("某个学生--------------------");
System.out.println(student);
System.out.println("某个学生--------------------");
for (Student s:students){
System.out.println(s);
}
//5.管理资源与提交事务
sqlSession.close();
}
}
结果:
E:\Java\jdk1.8.0_301\bin\java.exe -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:E:\IDEA\idea\IntelliJ IDEA 2020.1\lib\idea_rt.jar=8837:E:\IDEA\idea\IntelliJ IDEA 2020.1\bin" -Dfile.encoding=UTF-8 -classpath "E:\IDEA\idea\IntelliJ IDEA 2020.1\lib\idea_rt.jar;E:\IDEA\idea\IntelliJ IDEA 2020.1\plugins\junit\lib\junit5-rt.jar;E:\IDEA\idea\IntelliJ IDEA 2020.1\plugins\junit\lib\junit-rt.jar;E:\java\jdk1.8.0_301\jre\lib\charsets.jar;E:\java\jdk1.8.0_301\jre\lib\deploy.jar;E:\java\jdk1.8.0_301\jre\lib\ext\access-bridge-64.jar;E:\java\jdk1.8.0_301\jre\lib\ext\cldrdata.jar;E:\java\jdk1.8.0_301\jre\lib\ext\dnsns.jar;E:\java\jdk1.8.0_301\jre\lib\ext\jaccess.jar;E:\java\jdk1.8.0_301\jre\lib\ext\jfxrt.jar;E:\java\jdk1.8.0_301\jre\lib\ext\localedata.jar;E:\java\jdk1.8.0_301\jre\lib\ext\nashorn.jar;E:\java\jdk1.8.0_301\jre\lib\ext\sunec.jar;E:\java\jdk1.8.0_301\jre\lib\ext\sunjce_provider.jar;E:\java\jdk1.8.0_301\jre\lib\ext\sunmscapi.jar;E:\java\jdk1.8.0_301\jre\lib\ext\sunpkcs11.jar;E:\java\jdk1.8.0_301\jre\lib\ext\zipfs.jar;E:\java\jdk1.8.0_301\jre\lib\javaws.jar;E:\java\jdk1.8.0_301\jre\lib\jce.jar;E:\java\jdk1.8.0_301\jre\lib\jfr.jar;E:\java\jdk1.8.0_301\jre\lib\jfxswt.jar;E:\java\jdk1.8.0_301\jre\lib\jsse.jar;E:\java\jdk1.8.0_301\jre\lib\management-agent.jar;E:\java\jdk1.8.0_301\jre\lib\plugin.jar;E:\java\jdk1.8.0_301\jre\lib\resources.jar;E:\java\jdk1.8.0_301\jre\lib\rt.jar;D:\SSM_MybatisOne\SSM_Mybatis_Student\target\test-classes;D:\SSM_MybatisOne\SSM_Mybatis_Student\target\classes;C:\Users\小苏\.m2\repository\junit\junit\4.13.2\junit-4.13.2.jar;C:\Users\小苏\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Users\小苏\.m2\repository\org\mybatis\mybatis\3.5.11\mybatis-3.5.11.jar;C:\Users\小苏\.m2\repository\mysql\mysql-connector-java\5.1.46\mysql-connector-java-5.1.46.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 StudentCRUDTest.StudentTest,test01 Logging initialized using 'class org.apache.ibatis.logging.stdout.StdOutImpl' adapter. PooledDataSource forcefully closed/removed all connections. PooledDataSource forcefully closed/removed all connections. PooledDataSource forcefully closed/removed all connections. PooledDataSource forcefully closed/removed all connections. Opening JDBC Connection Created connection 1909546776. Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@71d15f18] ==> Preparing: select stuID stuId,stuName stuName,stuSalary stuSalary from student ==> Parameters: <== Columns: stuId, stuName, stuSalary <== Row: 10001, 苏宝全, 2000.365 <== Row: 10002, 苏风严, 3000.451 <== Total: 2 ==> Preparing: select stuID stuId,stuName stuName,stuSalary stuSalary from student where stuId=? ==> Parameters: 10001(Integer) <== Columns: stuId, stuName, stuSalary <== Row: 10001, 苏宝全, 2000.365 <== Total: 1 某个学生-------------------- Student{stuId=10001, stuName='苏宝全', stuSalary=2000.365} 某个学生-------------------- Student{stuId=10001, stuName='苏宝全', stuSalary=2000.365} Student{stuId=10002, stuName='苏风严', stuSalary=3000.451} Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@71d15f18] Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@71d15f18] Returned connection 1909546776 to pool. Process finished with exit code 0
场景三:传入多个简单类型
mapper接口中的方法不能出现重载,重载会导致在Mapper.xml中无法根据id查找到对应的接口方法