此次在項目中遇到了一個奇怪的問題, 就是在每隔一段時間訪問服務器就會報鏈接超時的錯誤,但在次請求就不會出現該問題,剛開始覺得是服務器那邊數據庫的問題,可是發現其餘項目中都沒有這種問題,因此查了好久發現原來是數據鏈接池這塊的相關參數根本沒有配置,這才致使出現的這樣的錯誤,耽擱的這麼長時間;都怪我太大意,因此寫下來這個錯誤,下次就不要在犯了;java
這裏推薦一個很好用的數據鏈接池:mysql
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.29</version> </dependency>
string-mybatis.xml中相關配置:web
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd "> <context:component-scan base-package="com.xt.shop.base.service.impl" /> <context:annotation-config /> <tx:annotation-driven /> <!-- 讀取JDBC的配置--> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="locations" value="classpath:jdbc.properties"/> </bean> <!-- 配置數據源,從上面配置文件讀取--> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="url" value="${jdbc.url}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <!--==============DRUID鏈接池相關配置==================--> <!--初始化時創建物理鏈接的個數--> <property name="initialSize" value="5"/> <!--最小鏈接池數量--> <property name="minIdle" value="10"/> <!--最大鏈接池數量--> <property name="maxActive" value="100"/> <!--鏈接時最大等待時間,單位毫秒--> <property name="maxWait" value="60000"/> <!--配置間隔多久才進行一次檢測,檢測須要關閉的空閒鏈接,單位是毫秒--> <property name="timeBetweenEvictionRunsMillis" value="60000"/> <!--配置一個鏈接在池中最小生存的時間,單位是毫秒--> <property name="minEvictableIdleTimeMillis" value="300000"/> <!--用來檢測鏈接是否有效的SQL,要求是一個查詢語句--> <property name="validationQuery" value="SELECT 1 FROM DUAL"/> <!--申請鏈接時執行 validationQuery 檢測鏈接是否有效,作了這個配置會下降性能--> <property name="testOnBorrow" value="true"/> <!--歸還鏈接時執行 validationQuery 檢測鏈接是否有效,作了這個配置會下降性能--> <property name="testOnReturn" value="true"/> <!--建議配置爲true,不影響性能,而且保證安全性;申請鏈接的時候檢測,若是空閒時間大於 timeBetweenEvictionRunsMillis,執行 validationQuery 檢測鏈接是否有效--> <property name="testWhileIdle" value="true"/> <!--是否緩存preparedStatement,也就是 PSCache--> <property name="poolPreparedStatements" value="true"/> <!--指定每一個鏈接上 PSCache 的大小--> <property name="maxOpenPreparedStatements" value="20"/> <!-- 打開清除廢棄鏈接功能 --> <property name = "removeAbandoned" value = "true"/> <!--清除廢棄鏈接的超時時間--> <property name="removeAbandonedTimeout" value="1800"/> <!-- 關閉 清除 鏈接時輸出錯誤日誌 --> <property name = "logAbandoned" value = "true"/> <!--配置監控統計攔截的filters,屬性類型是字符串,經過別名的方式配置擴展插件, 經常使用的插件有:監控統計用的STAT;日誌用的log4j;防護SQL注入的wall--> <property name="filters" value="stat,wall,log4j"/> <!--經過 connectProperties 屬性來打開mergeSql功能;慢SQL記錄--> <property name="connectionProperties" value="druid.stat.merggSql=ture;druid.stat.slowSqlMillis=5000"/> <!--合併多個DruidDataSource的監控數據--> <property name="useGlobalDataSourceStat" value="true"/> </bean> <!-- MyBatis_Plus配置: --> <bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <!-- 配置掃描實體的包路徑 --> <property name="typeAliasesPackage" value="com.xt.shop.base.entity"/> <!-- 配置掃描 MAPPER XML的位置 --> <property name="mapperLocations" value="classpath:mybatis/mapper/*.xml"/> <!-- 配置 MyBatis配置文件的位置 --> <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/> <property name="globalConfig" ref="globalConfig"/> <!-- 配置插件 --> <property name="plugins"> <array> <!-- 分頁插件配置 --> <bean id="paginationInterceptor" class="com.baomidou.mybatisplus.plugins.PaginationInterceptor"> <property name="dialectType" value="mysql"/> <property name="optimizeType" value="aliDruid" /> </bean> </array> </property> </bean> <!-- MP 全局配置注入 --> <bean id="globalConfig" class="com.baomidou.mybatisplus.entity.GlobalConfiguration"> <property name="idType" value="0"/> <property name="dbColumnUnderline" value="true"/> </bean> <!-- 配置掃描MAPPER接口的包路徑 --> <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.xt.shop.base.mapper"/> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> <!-- 事務處理 --> <bean id= "transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- 事務註解:開啓註解支持--> <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/> <!-- 全局AOP事物,除get,list,select,query開頭的方法外,都處在事物當中 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="select*" propagation="REQUIRED" read-only="true" /> <tx:method name="get*" propagation="REQUIRED" read-only="true" /> <tx:method name="list*" propagation="REQUIRED" read-only="true" /> <tx:method name="query*" propagation="REQUIRED" read-only="true" /> <tx:method name="*" propagation="REQUIRED" read-only="false" rollback-for="java.lang.Exception"/> </tx:attributes> </tx:advice> <!-- 配置事務切面 到Service層 --> <aop:config expose-proxy="true" proxy-target-class="true" > <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.xt.shop.base.service..*.*(..))"/> </aop:config> </beans>
web.xml中相關配置:spring
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/spring-mybatis.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class> </listener> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <filter> <filter-name>SetCharacterEncoding</filter-name> <filter-class> com.xt.shop.base.interceptor.SimpleCORSFilter </filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>SetCharacterEncoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>Spring MVC</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/spring-mvc.xml</param-value> </init-param> <load-on-startup>2</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Spring MVC</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <filter> <filter-name>DruidWebStatFilter</filter-name> <filter-class>com.alibaba.druid.support.http.WebStatFilter</filter-class> <init-param> <param-name>exclusions</param-name> <param-value>/static/*,*.ico,/druid/*</param-value> </init-param> <init-param> <param-name>sessionStatEnable</param-name> <param-value>false</param-value> </init-param> </filter> <filter-mapping> <filter-name>DruidWebStatFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!--===================DRUID監控====================--> <servlet> <servlet-name>DruidStatView</servlet-name> <servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class> <init-param> <!-- 用戶名 --> <param-name>loginUsername</param-name> <param-value>admin</param-value> </init-param> <init-param> <!-- 密碼 --> <param-name>loginPassword</param-name> <param-value>admin</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>DruidStatView</servlet-name> <url-pattern>/druid/*</url-pattern> </servlet-mapping> </web-app>
這樣就能夠在該服務器下 /druid 中訪問 Druid 中攔截到的信息了;sql