mybatis入门 mybatis入门_动力节点Java学院整理
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本文为大家分享了mybatis入门学习资料,供大家参考,具体内容如下
所需要用到的其他工具或技术:
项目管理工具 : Maven
测试运行工具 : Junit
数据库 : Derby
废话不多说,直接代码
Maven Dependencies:
<dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.7</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.9</version> <scope>test</scope> </dependency> <dependency> <groupId>org.apache.derby</groupId> <artifactId>derby</artifactId> <version>10.10.2.0</version> </dependency> <dependency> <groupId>org.apache.derby</groupId> <artifactId>derbyclient</artifactId> <version>10.10.2.0</version> </dependency> </dependencies>
SQL 建表及数据插入:
CREATE TABLE USER_TEST_TB( ID INT PRIMARY KEY, USERNAME VARCHAR(20) NOT NULL, PASSWORD VARCHAR(20) NOT NULL, NICKNAME VARCHAR(20) NOT NULL ); INSERT INTO USER_TEST_TB VALUES(1,'1st','111','Jack'); INSERT INTO USER_TEST_TB VALUES(2,'2nd','222','Rose'); INSERT INTO USER_TEST_TB VALUES(3,'3rd','333','Will');
Mybatis配置文件 src/main/resource源目录下
test-mybatis-configuration.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> <property name="driver" value="org.apache.derby.jdbc.ClientDriver" /> <property name="url" value="jdbc:derby://localhost:1527/freud;create=true" /> </properties> <environments default="development"> <environment id="development"> <transactionManager type="JDBC" /> <dataSource type="POOLED"> <property name="driver" value="${driver}" /> <property name="url" value="${url}" /> </dataSource> </environment> </environments> <mappers> <!-- <mapper class="com.freud.practice.UserMapper" /> --> <mapper resource="com/freud/practice/UserMapper.xml" /> </mappers> </configuration>
UserMapper.xml Mapper文件(src/main/java/com.freud.practice目录下)
<?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.freud.practice.UserMapper"> <select id="getUser" resultType="com.freud.practice.User"> select * from USER_TEST_TB </select> </mapper>
User.Java对象类(src/main/java/com.freud.practice目录下)
package com.freud.practice; public class User { private Integer id; private String username; private String password; private String nickname; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getNickname() { return nickname; } public void setNickname(String nickname) { this.nickname = nickname; } }
UserMapper.java Mapper类(src/main/java/com.freud.practice目录下)
package com.freud.practice; import java.util.List; import org.apache.ibatis.annotations.Select; public interface UserMapper { //@Select("SELECT * FROM USER_TEST_TB") public List<User> getUser(); }
测试类TestMyBatis.java(src/test/java/com.freud.practice目录下)
package com.freud.practice; import java.io.InputStream; import java.text.MessageFormat; import java.util.List; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.Before; import org.junit.Test; public class TestMyBatis { private String source; private InputStream inputStream; private SqlSessionFactory sqlSessionFactory; @Before public void setUp() { source = "test-mybatis-configuration.xml"; } @Test public void testXMLConfingureSessionFactory() { try { inputStream = TestMyBatis.class.getClassLoader().getResourceAsStream(source); sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); SqlSession session = sqlSessionFactory.openSession(); List<User> users = (List) session.selectList("com.freud.practice.UserMapper.getUser"); System.out.println("Query by XML configuration..."); this.printUsers(users); UserMapper userMapper = session.getMapper(UserMapper.class); System.out.println("\r\nQuery by annotation configuration..."); this.printUsers(userMapper.getUser()); } catch (Exception e) { e.printStackTrace(); } } private void printUsers(final List<User> users) { int count = 0; for (User user : users) { System.out.println(MessageFormat.format("==User[{0}]=================", ++count)); System.out.println("User Id: " + user.getId()); System.out.println("User UserName: " + user.getUsername()); System.out.println("User Password: " + user.getPassword()); System.out.println("User nickname: " + user.getNickname()); } } }
以上是使用XML作为Mapper配置文件的一个入门,其实Mybatis还支持Annotation的方式,具体操作如下:
1. 打开UserMapper.java中的注释。
2. 打开test-mybatis-configuration.xml中的注释,并注释掉现有的Mapper
3. 删除UserMapper.xml文件
这种是Mybatis的Annotation方式的Mapper配置。个人比较偏向于XML方式,所以后续的教程会更倾向于XML配置的方式来写。
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