Maven+Mybatis一些简单例子
一、创建maven工程
把依赖的包写在pom.xml中。保存后,工程会有错,需要在工程上右键选择“Maven-->Update Project”
pom.xml内容为
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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.mybatis</groupId> <artifactId>example</artifactId> <version>0.0.1-SNAPSHOT</version> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.3.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.38</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.12</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.12</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> </dependencies> <build> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> </plugins> </build> </project>
二、简单的例子
①创建数据库mybatis,创建表sys_user,sys_role,sys_user_role,并插入数据
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DROP TABLE IF EXISTS `sys_user`; CREATE TABLE `sys_user` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '用户Id', `user_name` varchar(50) DEFAULT NULL COMMENT '用户名', `user_password` varchar(50) DEFAULT NULL COMMENT '密码', `user_email` varchar(50) DEFAULT NULL COMMENT '邮箱', `user_info` text COMMENT '简介', `head_img` blob COMMENT '头像', `create_time` datetime DEFAULT NULL COMMENT '创建时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户表'; INSERT INTO `sys_user` VALUES ('1', 'admin', '123456', 'admin@mybatis.tk', '管理员', null, '2018-11-30 17:00:00'); INSERT INTO `sys_user` VALUES ('2', 'test', '123456', 'test@mybatis.org', 'test info', 0x7B, '2018-12-05 13:45:45'); -- ----- CREATE TABLE `sys_role` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '角色Id', `role_name` varchar(50) DEFAULT NULL COMMENT '用户名', `enabled` int(11) DEFAULT NULL COMMENT '有效标识', `create_by` bigint(20) DEFAULT NULL COMMENT '创建人', `create_time` datetime DEFAULT NULL COMMENT '创建时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='角色表'; INSERT INTO `sys_role` VALUES ('1', '管理员', '1', '1', '2018-11-30 17:05:00'); INSERT INTO `sys_role` VALUES ('2', '普通用户', '1', '1', '2018-11-30 17:05:01'); -- ------ CREATE TABLE `sys_user_role` ( `user_id` bigint(20) DEFAULT NULL COMMENT '用户Id', `role_id` bigint(20) DEFAULT NULL COMMENT '角色Id' ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户角色关联表'; INSERT INTO `sys_user_role` VALUES ('1', '1'); INSERT INTO `sys_user_role` VALUES ('1', '2'); INSERT INTO `sys_user_role` VALUES ('1001', '2');
②创建mybatis配置文件mybatis-config.xml,位置src/main/resources下
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<?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> <settings> <setting name="logImpl" value="LOG4J"/> </settings> <typeAliases> <package name="org.mybatis.example.model"/> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"> <property name="" value=""/> </transactionManager> <dataSource type="UNPOOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/> <property name="username" value="root"/> <property name="password" value="root"/> </dataSource> </environment> </environments> <mappers> <!-- <package name="org.mybatis.example.mapper"/> --> <mapper resource="org/mybatis/example/mapper/UserMapper.xml"/> <mapper resource="org/mybatis/example/mapper/RoleMapper.xml"/> </mappers> </configuration>
③创建model,SysUser,SysRole和SysUserRole,位置src/main/java下,包org.mybatis.example.model
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package org.mybatis.example.model; import java.util.Date; public class SysUser { private Long id; private String userName; private String userPassword; private String userEmail; private String userInfo; private byte[] headImg; private Date createTime; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getUserPassword() { return userPassword; } public void setUserPassword(String userPassword) { this.userPassword = userPassword; } public String getUserEmail() { return userEmail; } public void setUserEmail(String userEmail) { this.userEmail = userEmail; } public String getUserInfo() { return userInfo; } public void setUserInfo(String userInfo) { this.userInfo = userInfo; } public byte[] getHeadImg() { return headImg; } public void setHeadImg(byte[] headImg) { this.headImg = headImg; } public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } }
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package org.mybatis.example.model; import java.util.Date; public class SysRole { private Long id; private String roleName; private int enabled; private Long createBy; private Date createTime; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getRoleName() { return roleName; } public void setRoleName(String roleName) { this.roleName = roleName; } public int getEnabled() { return enabled; } public void setEnabled(int enabled) { this.enabled = enabled; } public Long getCreateBy() { return createBy; } public void setCreateBy(Long createBy) { this.createBy = createBy; } public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } }
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package org.mybatis.example.model; public class SysUserRole { private Long userId; private Long roleId; public Long getUserId() { return userId; } public void setUserId(Long userId) { this.userId = userId; } public Long getRoleId() { return roleId; } public void setRoleId(Long roleId) { this.roleId = roleId; } }
④创建映射的xml文件,UserMapper.xml,位置src/main/resources/org/mybatis/example/mapper下
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<?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="org.mybatis.example.mapper.UserMapper"> <select id="selectUserById" resultMap="selectUserMap"> select * from sys_user where id = #{id} </select> <resultMap type="org.mybatis.example.model.SysUser" id="selectUserMap"> <id property="id" column="id" /> <result property="userName" column="user_name"/> <result property="userPassword" column="user_password"/> <result property="userEmail" column="user_email"/> <result property="userInfo" column="user_info"/> <result property="headImg" column="head_img" jdbcType="BLOB"/> <result property="createTime" column="create_time" jdbcType="TIMESTAMP"/> </resultMap> </mapper>
⑤创建Mapper的接口,UserMapper.java,位置src/main/java下,包org.mybatis.example.mapper
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package org.mybatis.example.mapper; import org.mybatis.example.model.SysUser; public interface UserMapper { SysUser selectUserById(Long id); }
⑥创建测试程序,TestSelectMapper.java,位置src/main/java下,包org.mybatis.example.app
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package org.mybatis.example.app; import java.io.IOException; import java.io.Reader; import java.util.List; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.BeforeClass; import org.junit.Test; import org.mybatis.example.mapper.RoleMapper; import org.mybatis.example.mapper.UserMapper; import org.mybatis.example.model.SysRole; import org.mybatis.example.model.SysUser; import junit.framework.Assert; public class TestSelectMapper { private static SqlSessionFactory sqlSessionFactory; @BeforeClass public static void init() { try { Reader reader = Resources.getResourceAsReader("mybatis-config.xml"); sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader); reader.close(); } catch (IOException e) { e.printStackTrace(); } } @Test public void testSelectUserById() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); SysUser sysUser = userMapper.selectUserById(1L); Assert.assertNotNull(sysUser); Assert.assertEquals("admin", sysUser.getUserName()); System.out.println(sysUser.toString()); } finally { sqlSession.close(); } } }
三、综合增删改查
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<?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="org.mybatis.example.mapper.UserMapper"> <select id="selectUserById" resultMap="selectUserMap"> select * from sys_user where id = #{id} </select> <resultMap type="org.mybatis.example.model.SysUser" id="selectUserMap"> <id property="id" column="id" /> <result property="userName" column="user_name"/> <result property="userPassword" column="user_password"/> <result property="userEmail" column="user_email"/> <result property="userInfo" column="user_info"/> <result property="headImg" column="head_img" jdbcType="BLOB"/> <result property="createTime" column="create_time" jdbcType="TIMESTAMP"/> </resultMap> <select id="selectAllUsers" resultType="org.mybatis.example.model.SysUser"> select user_name userName, user_password userPassword, user_email userEmail, user_info userInfo, user_info userInfo, head_img headImg, create_time createTime from sys_user </select> <insert id="insertAUser"> insert into sys_user (id, user_name, user_password, user_email, user_info, head_img, create_time) values (#{id}, #{userName}, #{userPassword}, #{userEmail}, #{userInfo}, #{headImg, jdbcType=BLOB}, #{createTime, jdbcType=TIMESTAMP}) </insert> <insert id="insertAUserWithoutId" useGeneratedKeys="true" keyProperty="id"> insert into sys_user (user_name, user_password, user_email, user_info, head_img, create_time) values (#{userName}, #{userPassword}, #{userEmail}, #{userInfo}, #{headImg, jdbcType=BLOB}, #{createTime, jdbcType=TIMESTAMP}) </insert> <update id="updateAUser"> update sys_user set user_name = #{userName}, user_email = #{userEmail}, user_info = #{userInfo}, create_time = #{createTime, jdbcType=TIMESTAMP} where id = #{id} </update> <delete id="deleteAUser"> delete from sys_user where id = #{id} </delete> </mapper>
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package org.mybatis.example.mapper; import java.util.List; import org.mybatis.example.model.SysUser; public interface UserMapper { SysUser selectUserById(Long id); List<SysUser> selectAllUsers(); int insertAUser(SysUser sysUser); int insertAUserWithoutId(SysUser sysUser); int updateAUser(SysUser sysUser); int deleteAUser(Long id); }
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<?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="org.mybatis.example.mapper.RoleMapper"> <select id="selectRolesByUserId" resultType="org.mybatis.example.model.SysRole"> select r.id, r.role_name roleName, r.enabled, r.create_by createBy, r.create_time createTime from sys_user u inner join sys_user_role ur on u.id = ur.user_id inner join sys_role r on r.id = ur.role_id where u.id = #{userId} </select> <select id="selectRolesByUserIdAndRoleEnabled" resultType="org.mybatis.example.model.SysRole"> select r.id, r.role_name roleName, r.enabled, r.create_by createBy, r.create_time createTime from sys_user u inner join sys_user_role ur on u.id = ur.user_id inner join sys_role r on r.id = ur.role_id where u.id = #{userId} and r.enabled = #{enabled} </select> </mapper>
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package org.mybatis.example.mapper; import java.util.List; import org.apache.ibatis.annotations.Param; import org.mybatis.example.model.SysRole; public interface RoleMapper { List<SysRole> selectRolesByUserId(Long id); List<SysRole> selectRolesByUserIdAndRoleEnabled( @Param("userId") Long userId, @Param("enabled") int enabled); }
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package org.mybatis.example.app; import java.io.IOException; import java.io.Reader; import java.util.List; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.BeforeClass; import org.junit.Test; import org.mybatis.example.mapper.RoleMapper; import org.mybatis.example.mapper.UserMapper; import org.mybatis.example.model.SysRole; import org.mybatis.example.model.SysUser; import junit.framework.Assert; public class TestSelectMapper { private static SqlSessionFactory sqlSessionFactory; @BeforeClass public static void init() { try { Reader reader = Resources.getResourceAsReader("mybatis-config.xml"); sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader); reader.close(); } catch (IOException e) { e.printStackTrace(); } } @Test public void testSelectUserById() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); SysUser sysUser = userMapper.selectUserById(1L); Assert.assertNotNull(sysUser); Assert.assertEquals("admin", sysUser.getUserName()); System.out.println(sysUser.toString()); } finally { sqlSession.close(); } } @Test public void testSelectAllUsers() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); List<SysUser> sysUserList = userMapper.selectAllUsers(); Assert.assertNotNull(sysUserList); Assert.assertTrue(sysUserList.size() > 0); System.out.println(sysUserList.size()); } finally { sqlSession.close(); } } @Test public void testSelectRolesByUserId() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { RoleMapper rolerMapper = sqlSession.getMapper(RoleMapper.class); List<SysRole> sysRoleList = rolerMapper.selectRolesByUserId(1L); Assert.assertNotNull(sysRoleList); Assert.assertTrue(sysRoleList.size() > 0); System.out.println(sysRoleList.size()); } finally { sqlSession.close(); } } }
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package org.mybatis.example.app; import java.io.IOException; import java.io.Reader; import java.util.Date; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.BeforeClass; import org.junit.Test; import org.mybatis.example.mapper.UserMapper; import org.mybatis.example.model.SysUser; public class TestInsertMapper { private static SqlSessionFactory sqlSessionFactory; @BeforeClass public static void init() { try { Reader reader = Resources.getResourceAsReader("mybatis-config.xml"); sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader); reader.close(); } catch (IOException e) { e.printStackTrace(); } } @Test public void testInsertAUser() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); SysUser sysUser = new SysUser(); sysUser.setId(2L); sysUser.setUserName("test"); sysUser.setUserPassword("123456"); sysUser.setUserEmail("test@mybatis.org"); sysUser.setUserInfo("test info"); sysUser.setHeadImg(new byte[] {123}); sysUser.setCreateTime(new Date()); int insertResult = userMapper.insertAUser(sysUser); System.out.println(insertResult); } finally { //sqlSession.rollback(); sqlSession.commit(); sqlSession.close(); } } @Test public void testInsertAUserWithoutId() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); SysUser sysUser = new SysUser(); sysUser.setUserName("test3"); sysUser.setUserPassword("123456"); sysUser.setUserEmail("test3@mybatis.org"); sysUser.setUserInfo("test3 info"); sysUser.setCreateTime(new Date()); int insertResult = userMapper.insertAUser(sysUser); System.out.println(insertResult); } finally { //sqlSession.rollback(); sqlSession.commit(); sqlSession.close(); } } @Test public void testUpdateAUser() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); SysUser selectUser = userMapper.selectUserById(1003L); selectUser.setUserName("test1003"); selectUser.setUserEmail("test1003@mybatis.org"); selectUser.setUserInfo("test1003 info"); selectUser.setCreateTime(new Date()); int updateResult = userMapper.updateAUser(selectUser); System.out.println(updateResult); } finally { sqlSession.commit(); sqlSession.close(); } } @Test public void testDeleteAUser() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { UserMapper userMapper = sqlSession.getMapper(UserMapper.class); int deleteResult = userMapper.deleteAUser(1003L); System.out.println(deleteResult); } finally { sqlSession.commit(); sqlSession.close(); } } }
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package org.mybatis.example.app; import java.io.IOException; import java.io.Reader; import java.util.List; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.BeforeClass; import org.junit.Test; import org.mybatis.example.mapper.RoleMapper; import org.mybatis.example.model.SysRole; public class TestParamMapper { private static SqlSessionFactory sqlSessionFactory; @BeforeClass public static void init() { try { Reader reader = Resources.getResourceAsReader("mybatis-config.xml"); sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader); reader.close(); } catch (IOException e) { e.printStackTrace(); } } @Test public void testComplicatedSelect() { SqlSession sqlSession = sqlSessionFactory.openSession(); try { RoleMapper roleMapper = sqlSession.getMapper(RoleMapper.class); List<SysRole> sysRoleList = roleMapper.selectRolesByUserIdAndRoleEnabled(1L, 1); System.out.println(sysRoleList.size()); } finally { sqlSession.close(); } } }
当需要传递多个参数的时候,需要用到@Param注解,并且上面的代码中给出了例子:RoleMapper.xml中的SelectRolesByUserIdAndRoleEnabled
需要注意的是,在Mapper.xml中,<mapper>中的属性namespace不能少,之前在学习的过程由于缺少了namespace,导致没有得到正确的结果,排查了半天,才找到原因
四、架构图