前言
上一遍只是简单的说明了怎么加入Mybatis,但这远远还是不够,我们还需要加入数据库连池来帮助我们来管理数据库连接。
1、加spring boot druid 依赖
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.8</version>
</dependency>
注意,你的spring boot版本,如果是spring boot 是2.x 以上那么druid-spring-boot-starter
的版本号也要相应的比较高的版本,在引入druid-spring-boot-starter
依赖的时候,我刚开始引入的比较低的版本1.1.5
结果执行测试类时一直报错:
在升级完druid的版本号后,就不再报错了。
2、durid配置文件
在application.properties
文件中添加配置
#连接池的配置信息
## 初始化大小,最小,最大
spring.datasource.druid.initialSize=5
spring.datasource.druid.minIdle=5
spring.datasource.druid.maxActive=20
## 配置获取连接等待超时的时间
spring.datasource.druid.maxWait=60000
# 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒
spring.datasource.druid.timeBetweenEvictionRunsMillis=60000
# 配置一个连接在池中最小生存的时间,单位是毫秒
spring.datasource.druid.minEvictableIdleTimeMillis=300000
spring.datasource.druid.validationQuery=SELECT 1 FROM DUAL
spring.datasource.druid.testWhileIdle=true
spring.datasource.druid.testOnBorrow=false
spring.datasource.druid.testOnReturn=false
spring.datasource.druid.poolPreparedStatements=true
spring.datasource.druid.maxPoolPreparedStatementPerConnectionSize=20
# 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙
spring.datasource.druid.filters=stat,wall,log4j
# 通过connectProperties属性来打开mergeSql功能;慢SQL记录
spring.datasource.druid.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
3、添加数据源类
@Configuration
//在这里添加MapperScan 扫包,在启动类中就不用再添加了
@MapperScan(basePackages = "com.clockbone.dao",sqlSessionFactoryRef = "sqlSessionFactory")
public class DruidDatabaseConfiguration {
/*@Value(value = "spring.datasource.url")
private String dbUrl;
@Value(value = "spring.datasource.username")
private String username;
@Value(value = "spring.datasource.password")
private String password;
@Value(value = "spring.datasource.driver-class-name")
private String driverClassName;
@Value(value = "spring.druid.initialSize")
private int initialSize;
@Value(value = "spring.druid.minIdle")
private int minIdle;
@Value(value = "spring.druid.maxActive")
private int maxActive;
@Value(value = "spring.druid.maxWait")
private int maxWait;
@Value(value = "spring.druid.timeBetweenEvictionRunsMillis")
private int timeBetweenEvictionRunsMillis;
@Value(value = "spring.druid.minEvictableIdleTimeMillis")
private int minEvictableIdleTimeMillis;
@Value(value = "spring.druid.validationQuery")
private String validationQuery;
@Value(value = "spring.druid.testWhileIdle")
private boolean testWhileIdle;
@Value(value = "spring.druid.testOnBorrow")
private boolean testOnBorrow;
@Value(value = "spring.druid.testOnReturn")
private boolean testOnReturn;
@Value(value = "spring.druid.poolPreparedStatements")
private boolean poolPreparedStatements;
@Value(value = "spring.druid.maxPoolPreparedStatementPerConnectionSize")
private int maxPoolPreparedStatementPerConnectionSize;
@Value(value = "spring.druid.filtersl")
private String filters;
@Value(value = "spring.druid.connectionProperties")
private String connectionProperties;*/
@Bean
//统一配置名前缀,可以减少上面配置代码
@ConfigurationProperties(prefix = "spring.datasource")
@Primary
public DruidDataSource dataSource() throws SQLException {
DruidDataSource datasource = new DruidDataSource();
/*datasource.setUrl(this.dbUrl);
datasource.setUsername(username);
datasource.setPassword(password);
datasource.setDriverClassName(driverClassName);
//configuration
datasource.setInitialSize(initialSize);
datasource.setMinIdle(minIdle);
datasource.setMaxActive(maxActive);
datasource.setMaxWait(maxWait);
datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
datasource.setValidationQuery(validationQuery);
datasource.setTestWhileIdle(testWhileIdle);
datasource.setTestOnBorrow(testOnBorrow);
datasource.setTestOnReturn(testOnReturn);
datasource.setPoolPreparedStatements(poolPreparedStatements); datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
datasource.setFilters(filters);*/
return datasource;
}
@Bean
public DataSourceTransactionManager transactionManager() throws SQLException {
return new DataSourceTransactionManager(dataSource());
}
@Bean
public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
sessionFactory.setDataSource(dataSource);
sessionFactory.setMapperLocations(resolver.getResources("classpath:mapper/*.xml"));
/*PageHelper pageHelper = new PageHelper();
Properties properties = new Properties();
properties.setProperty("reasonable", "true");
properties.setProperty("supportMethodsArguments", "true");
properties.setProperty("returnPageInfo", "check");
properties.setProperty("params", "count=countSql");
pageHelper.setProperties(properties);
sessionFactory.setPlugins(new Interceptor[]{pageHelper});*/
return sessionFactory.getObject();
}
}
4、mapper类及文件
//UserMapper.java
//@Mapper 可以去掉这个注解了
public interface UserMapper {
@Select("SELECT ID,USER_ID as userId,USER_NAME as userName FROM Userinfo where id=#{id}")
User getUserInfo(long id);
User selectByPrimaryKey(Long id);
}
//UserMapper.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" >
<mapper namespace="com.clockbone.dao.UserMapper" >
<resultMap id="BaseResultMap" type="com.clockbone.model.User" >
<id column="id" property="id" jdbcType="INTEGER" />
<result column="user_name" property="userName" jdbcType="VARCHAR" />
<result column="user_id" property="userId" jdbcType="VARCHAR" />
</resultMap>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Long" >
select
user_id as userId,user_name userName,id
from User
where id = #{id}
</select>
</mapper>
5、加spring boot 加入pagehelper分页插件
pagehelper
这个插件也是比较常用的数据分页插件,在spring boot
只需要加入下面依赖,就会自动在sqlSessionFactory
层面自动加入pagehelper的插件配置,而不需要再另外配置插件代码:
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.5</version>
</dependency>
测试类:
@Test
public void userPageInfoTest(){
User user = new User();
user.setUserName("test");
//直接设置分页属性,为了保证安全分页,后面一条一定是要分页的sql,
PageInfo<User> pageInfo = userService.getUserList(user,1,10);
log.info("getTotal:{}",pageInfo.getTotal());
log.info("getPageNum:{}",pageInfo.getPageNum());
log.info("getPageSize:{}",pageInfo.getPageSize());
log.info("page list:{}",pageInfo.getList());
}
结果:
2018-05-09 17:46:04.528 INFO 4628 --- [ main] com.clockbone.web.biz.UserServiceTest : getTotal:1
2018-05-09 17:46:04.528 INFO 4628 --- [ main] com.clockbone.web.biz.UserServiceTest : getPageNum:1
2018-05-09 17:46:04.528 INFO 4628 --- [ main] com.clockbone.web.biz.UserServiceTest : getPageSize:10
如果不想spring boot自动注入,可以在sqlSessionFactory
的代码中设置pagehelper
插件:
@Bean
public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
sessionFactory.setDataSource(dataSource);
sessionFactory.setMapperLocations(resolver.getResources("classpath:mapper/*.xml"));
//添加Pagehelper插件
Interceptor pageHelper = new PageInterceptor();
Properties properties = new Properties();
properties.setProperty("reasonable", "true");
properties.setProperty("supportMethodsArguments", "true");
properties.setProperty("returnPageInfo", "check");
properties.setProperty("params", "count=countSql");
pageHelper.setProperties(properties);
sessionFactory.setPlugins(new Interceptor[]{pageHelper});
return sessionFactory.getObject();
}
* 这时如果直接启动测类,会报如下错误: *
会报有多个分页插件,这时需要在启动类上面加入注解 ,去掉pagehelper
插件的自动注入如下:
@SpringBootApplication(scanBasePackages = "com.clockbone"/*,
exclude={DataSourceAutoConfiguration.class}*/ ,exclude = {PageHelperAutoConfiguration.class})
pagehelper插件官网参考:
https://github.com/abel533/MyBatis-Spring-Boot