如何通過XML方式配置并實現Mybatis
idea中創建一個maven項目
在pom文件中導入下面的依賴
<!--mybatis核心包--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.6</version> </dependency> <!--mysql數據庫驅動包--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.18</version> </dependency> <!--log4j日志包--> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency>
創建一個java源文件夾和resources資源文件夾并準備好mybatis配置文件mybaits.xml和數據庫文件db.properties
mybaits.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> <!--數據庫參數文件--> <properties resource='db.properties'></properties> <!--別名的配置,可以不用--> <typeAliases> <package name='cn.cqy.domain'></package> </typeAliases> <!--配置環境,可以多個,這里要設置一個默認使用的環境--> <environments default='dev'> <!--配置環境名,唯一一個id名稱--> <environment id='dev'> <!--事務管理 type:JDBC(支持事務)/MANAGED(什么都不做)--> <transactionManager type='JDBC'></transactionManager> <!--數據源, 連接池 type(POOLED):MyBatis自帶的連接池--> <dataSource type='POOLED'><property name='driver' value='${driverClassName}'></property><property name='url' value='${url}'></property><property name='username' value='${username}'></property><property name='password' value='${password}'></property> </dataSource> </environment> </environments> <!--這個mappers代表的是相應的ORM映射文件 這里先準備好了--> <mappers> <mapper resource='cn/cqy/mapper/StudentMapper.xml'></mapper> </mappers></configuration>
db.properties
driverClassName=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/prc?userUnicode=true&characterEncoding=utf8&serverTimezone=UTCusername=rootpassword=root
數據庫準備
準備相應的對象
創建一個Student對象,和數據庫的表對應
public class Student { private String s_id; private String s_name; private String s_birth; private String s_sex; public Student() {} //getter,setter 方法省略}
mapper的準備 ,創建一個mapper文件夾,并在內創建一個StudentMapper接口
public interface StudentMapper {//查找學生表全部信息 public List<Student> selectAll();//根據姓名查找學生 public Student selectByName(String name);//插入一條學生信息 public void insertOne(Student stu);//根據姓名刪除一條學生信息 public void deleteByName(String name);//根據姓名修改一條學生信息 public void updateByName(Student stu);}
在resoures資源文件夾下創建和mapper文件夾路徑相同的文件夾
然后創建映射文件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'><!--命名空間 必須和所對應接口的全限定名一致--><mapper namespace='cn.cqy.mapper.StudentMapper'> <!--定義sql的標簽的id,需要和對應接口的方法名一致 resultType的類型在沒有配置別名的情況下,應該是POJO類的全限定名 如cn.cqy.domain.Student--> <select resultType='Student'> SELECT s_id,s_name,s_birth,s_sex FROM student </select> <!--參數類型為自定類型沒有別名,輸入類型全限定名,為Java類型時輸入其對應映射名 如 long:大Long _long:小long (具體的對應請參見文檔)--> <select resultType='Student' parameterType='String'> SELECT s_id,s_name,s_birth,s_sex FROM student WHERE s_name = #{name} </select> <insert parameterType='Student'> INSERT INTO student (s_id,s_name,s_birth,s_sex) VALUES (#{s_id},#{s_name},#{s_birth},#{s_sex}) </insert> <delete parameterType='String'> DELETE FROM student where s_name = #{s_name} </delete> <update parameterType='Student' > UPDATE student SET s_birth = #{s_birth},s_sex = #{s_sex} WHERE s_name = #{s_name} </update></mapper>
抽取出一個MybatisUtil工具類
public class MybatisUtil { private static SqlSessionFactory sqlSessionFactory;//靜態代碼塊:在使用的時候先執行,并且執行一次 static { try { InputStream is = Resources.getResourceAsStream('mybatis.xml'); SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder(); //創建一個工廠實例(加載了我們的配置文件) sqlSessionFactory = builder.build(is); } catch (IOException e) { e.printStackTrace(); } }/** *拿到了一個SqlSession對象 */ public static SqlSession getSqlSession() { return sqlSessionFactory.openSession(); } public static void closeSqlSession(SqlSession sqlSession) { if (sqlSession != null) { sqlSession.close(); } }}
編寫測試類
public class SqlTest { @Test public void testSelectAll() { //通過工具類獲得SqlSession對象 SqlSession sqlSession = MybatisUtil.getSqlSession(); //獲取到綁定到SqlSession的POJO類對應的映射 StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); //通過映射調用查詢方法 List<Student> students = studentMapper.selectAll(); //關閉SqlSession sqlSession.close(); for (Student student : students) { System.out.println(student); } } @Test public void testSelectByName() { SqlSession sqlSession = MybatisUtil.getSqlSession(); StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); Student stu = studentMapper.selectByName('吳蘭'); sqlSession.close(); System.out.println(stu); } @Test public void testInsertOne() { SqlSession sqlSession = MybatisUtil.getSqlSession(); StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); Student stu = new Student(); stu.setS_id('09'); stu.setS_name('李水'); stu.setS_birth('1988-08-22'); stu.setS_sex('男'); studentMapper.insertOne(stu); //增、刪、改需要提交事務,否則不會修改 sqlSession.commit(); sqlSession.close(); } @Test public void testDeleteByName() { SqlSession sqlSession = MybatisUtil.getSqlSession(); StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); studentMapper.deleteByName('李水'); sqlSession.commit(); sqlSession.close(); } @Test public void testUpdateByName() { SqlSession sqlSession = MybatisUtil.getSqlSession(); StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class); Student stu = new Student(); stu.setS_name('李水'); stu.setS_birth('1999-01-22'); stu.setS_sex('女'); studentMapper.updateByName(stu); sqlSession.commit(); sqlSession.close(); }}
測試查詢結果
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持好吧啦網。
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