mybatis使用-整合到spring构架
二、将mybatis整合到spring框架中
参照mybatis官方文档：http://mybatis.org/spring/zh/getting-started.html
官方文档介绍中，对Mapper的注入使用的是xml配置文件，本文使用的java代码配置实现。
代码结构：
1.使用eclipse创建maven项目，同时创建resources目录用于存放数据库连接配置文件。
2.修改pom.xml，增加spring、mybatis、mybatis-spring、mysql-connector、c3p0相关依赖包。
<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>com.test</groupId> <artifactId>mybatis-spring</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>mybatis-spring</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <springframework.version>5.0.8.RELEASE</springframework.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${springframework.version}</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.6</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.7</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.49</version> </dependency> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.5</version> </dependency> </dependencies> <build> <finalName>income</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.1</version> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> </plugins> </build> </project>
3.增加BootStrap.java类，同时增加@ComponentScan("com.test.mybatisspring")注解，使得AnnotationConfigApplicationContext扫描包下所有的@Service、@Component、@Configuration等组件，从容器中获取UserService类的实例，并调用它的valid方法验证用户名和密码是否与数据库内容一致。
package com.test.mybatisspring; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import org.springframework.context.annotation.ComponentScan; import com.test.mybatisspring.service.UserService; @ComponentScan("com.test.mybatisspring") public class BootStrap { public static void main( String[] args ) { AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(BootStrap.class); UserService userService = context.getBean(UserService.class); Integer id = 1; String password = "123456"; if(userService.valid(id, password)) { System.out.println("用户名与密码正确！"); } else { System.out.println("用户名或密码错误！"); } } }
4.在resources目录下创建jdbc.properties文件
jdbc.driverClassName=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/test?useSSL=false&useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&allowPublicKeyRetrieval=true&allowMultiQueries=true jdbc.username=root jdbc.password=111111
5.创建SysConfig配置类，获取jdbc.properties文件的数据库配置信息，增加dataSource、sqlSesstionFactory的bean实例注入到spring容器；再增加MapperFactoryBean的bean实例注入到spring中，由MapperFactoryBean将UserMapper接口的代理类注入到spring容器中。
package com.test.mybatisspring.config; import java.beans.PropertyVetoException; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.mapper.MapperFactoryBean; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.PropertySource; import org.springframework.context.annotation.PropertySources; import com.mchange.v2.c3p0.ComboPooledDataSource; import com.test.mybatisspring.mapper.UserMapper; @Configuration @PropertySource(value= {"classpath:jdbc.properties"}) public class SysConfig { @Value("${jdbc.driverClassName}") private String driverClassName; @Value("${jdbc.url}") private String url; @Value("${jdbc.username}") private String username; @Value("${jdbc.password}") private String password; @Bean(name="dataSource",destroyMethod="close") public ComboPooledDataSource dataSource() throws PropertyVetoException { ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setDriverClass(this.driverClassName); dataSource.setJdbcUrl(this.url); dataSource.setUser(this.username); dataSource.setPassword(this.password); return dataSource; } @Bean public SqlSessionFactory sqlSessionFactory() throws Exception { SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean(); factoryBean.setDataSource(dataSource()); return factoryBean.getObject(); } @Bean public MapperFactoryBean<UserMapper> mapperFactoryBean() throws Exception{ MapperFactoryBean<UserMapper> mapperFactoryBean = new MapperFactoryBean<UserMapper>(); mapperFactoryBean.setSqlSessionFactory(sqlSessionFactory()); mapperFactoryBean.setMapperInterface(UserMapper.class); return mapperFactoryBean; } }
在使用MapperFactoryBean注入接口代理类需要一个个增加，可以使用@MapperScan注解，针对类包注入:
@MapperScan("com.test.mybatisspring.mapper");
也可以替换使用MapperScannerConfigurer类来完成类包下Mapper的注入：
@Bean public static MapperScannerConfigurer mapperScannerConfigurer() throws Exception { MapperScannerConfigurer configure = new MapperScannerConfigurer(); configure.setBasePackage("com.test.mybatisspring.mapper"); configure.setAddToConfig(true); return configure; }
注意：由于MapperScannerConfigurer类是BeanFactoryPostProcessor，因此，MapperScannerConfigurer类的实例需求优先注入到spring容器，对应的注入方法必须是static的，否则程序会抛出警告，达不到mapper注入的效果。
警告信息“Cannot enhance @Configuration bean definition 'sysConfig' since its singleton instance has been created too early. The typical cause is a non-static @Bean method with a BeanDefinitionRegistryPostProcessor return type: Consider declaring such methods as 'static'.”
在@Bean注解的源码也有相应的说明：
* <p>Special consideration must be taken for {@code @Bean} methods that return Spring * {@link org.springframework.beans.factory.config.BeanFactoryPostProcessor BeanFactoryPostProcessor} * ({@code BFPP}) types. Because {@code BFPP} objects must be instantiated very early in the * container lifecycle, they can interfere with processing of annotations such as {@code @Autowired}, * {@code @Value}, and {@code @PostConstruct} within {@code @Configuration} classes. To avoid these * lifecycle issues, mark {@code BFPP}-returning {@code @Bean} methods as {@code static}. For example: * * <pre class="code"> * @Bean * public static PropertySourcesPlaceholderConfigurer pspc() { * // instantiate, configure and return pspc ... * } * </pre>
5.创建User实体类
package com.test.mybatisspring.entity; import java.util.Date; public class User { private Integer id; private String userName; private String password; private Date createTime; 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 Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } }
6.创建UserMapper接口，该接口由mybatis生成代理实现类。
package com.test.mybatisspring.mapper; import com.test.mybatisspring.entity.User; public interface UserMapper { User getUserById(Integer id); }
<?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.test.mybatisspring.mapper.UserMapper"> <resultMap type="com.test.mybatisspring.entity.User" id="userMap"> <id column="id" property="id"/> <result column="user_name" property="userName"/> <result column="password" property="password"/> <result column="create_time" property="createTime"/> </resultMap> <select id="getUserById" resultMap="userMap"> select * from user where id = #{id} </select> </mapper>
7.创建UserService服务类，设置UserMapper属性并使用@Autowired注入实现类的实例，调用UserMapper获取用User类的对象，完成密码的容易对比。
package com.test.mybatisspring.service; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.test.mybatisspring.entity.User; import com.test.mybatisspring.mapper.UserMapper; @Service public class UserService { @Autowired private UserMapper userMapper; public Boolean valid(Integer id,String password) { User user = userMapper.getUserById(id); System.out.println(user.getId() + "," + user.getUserName() + "," + user.getPassword() + "," + user.getCreateTime()); if(user.getPassword().equals(password)) { return true; } else { return false; } } }
链接：https://pan.baidu.com/s/1jdfNjKxZPg7GJRWslRbYug
提取码：3w9w
