今天總結下自己使用Druid遇到的一個錯誤“loopWaitCount 0, wait millis 6001”
報錯信息：
Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.alibaba.druid.pool.GetConnectionTimeoutException: loopWaitCount 0, wait millis 6001 at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80) at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:80) at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:66) at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:279) at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:69) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:56) at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:267) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:141) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:124) at sun.reflect.GeneratedMethodAccessor33.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.ibatis.plugin.Invocation.proceed(Invocation.java:46) at com.tzt.workLog.core.mybatis.plugin.SelectCountSqlInterceptor.intercept(SelectCountSqlInterceptor.java:49) at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:57) at com.sun.proxy.$Proxy155.query(Unknown Source) at sun.reflect.GeneratedMethodAccessor33.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.ibatis.plugin.Invocation.proceed(Invocation.java:46) at com.tzt.workLog.core.mybatis.plugin.OffsetLimitInterceptor.intercept(OffsetLimitInterceptor.java:53) at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:57) at com.sun.proxy.$Proxy155.query(Unknown Source) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:101) ... 55 more
系統用的框架是Spring+SpringMVC+Mybatis(SSM)，其中把涉及到的兩個配置部分列出來：
spring_service.xml
<!-- 配置數據庫連接 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<!-- 基本屬性 url、user、password -->
<property name="driverClassName" value="${jdbc-0.druid.driver-class}" />
<property name="url" value="${jdbc-0.druid.driver-url}" />
<property name="username" value="${jdbc-0.user}" />
<property name="password" value="${jdbc-0.password}" />
<!-- 配置初始化大小、最小、最大 -->
<property name="initialSize" value="${jdbc-0.druid.connection-initial-size}" />
<property name="minIdle" value="${jdbc-0.druid.connection-minimum-size}" />
<property name="maxActive" value="${jdbc-0.druid.connection-maximum-size}" />
<!-- 配置獲取連接等待超時的時間 -->
<property name="maxWait" value="${jdbc-0.druid.connection-maxwait-time}" />
<!-- 配置間隔多久才進行一次檢測，檢測需要關閉的空閒連接，單位是毫秒 -->
<property name="timeBetweenEvictionRunsMillis" value="${jdbc-0.druid.connection-maxactive-time}" />
<!-- 配置一個連接在池中最小生存的時間，單位是毫秒 -->
<property name="minEvictableIdleTimeMillis" value="${jdbc-0.druid.connection-minlive-time}" />
<property name="validationQuery" value="${jdbc-0.druid.connection-test-sql}" />
<property name="testWhileIdle" value="${jdbc-0.druid.test-while-idle}" />
<property name="testOnBorrow" value="${jdbc-0.druid.test-on-borrow}" />
<property name="testOnReturn" value="${jdbc-0.druid.test-on-return}" />
<!-- 打開PSCache，並且指定每個連接上PSCache的大小 -->
<property name="poolPreparedStatements" value="${jdbc-0.druid.pool-prepared-statements}" />
<!-- property name="maxPoolPreparedStatementPerConnectionSize" value="20" /-->
<!-- 數據庫密碼是否加密 -->
<property name="connectionProperties" value="config.decrypt=${jdbc-0.druid.config.decrypt}" />
<!-- 配置監控統計攔截的filters -->
<property name="filters" value="stat,config"/>
</bean>
db.properties:
jdbc-0.druid.alias=productDBPool
localhost
jdbc-0.druid.driver-class=com.mysql.jdbc.Driver
jdbc-0.druid.driver-url=jdbc:mysql://127.0.0.1:3306/zentao?useUnicode=true&characterEncoding=UTF8&zeroDateTimeBehavior=convertToNull
jdbc-0.user=root
jdbc-0.password=root
jdbc-0.druid.connection-initial-size=10
jdbc-0.druid.connection-minimum-size=10
jdbc-0.druid.connection-maximum-size=200
jdbc-0.druid.connection-maxwait-time=6000
jdbc-0.druid.connection-maxactive-time=6000
jdbc-0.druid.connection-minlive-time=300000
jdbc-0.druid.connection-test-sql=select 1 from dual
jdbc-0.druid.pool-prepared-statements=false
jdbc-0.druid.test-while-idle=true
jdbc-0.druid.test-on-borrow=false
jdbc-0.druid.test-on-return=false
jdbc-0.druid.config.decrypt=false總結，原因應該是配置中jdbc-0.druid.connection-maximum-size值設置太小,剛開始設置50，後來設置爲200