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首页 > 解决方案 > java.sql.SQLException: 无法获得连接，池错误 Timeout waiting for idle object 。如何恢复连接

java - java.sql.SQLException: 无法获得连接，池错误 Timeout waiting for idle object 。如何恢复连接

问题描述

我使用 java 8 和 apache tomcat。

执行项目，我收到以下错误

java.sql.SQLException: Cannot get a connection, pool error Timeout waiting for idle object
    at org.apache.tomcat.dbcp.dbcp2.PoolingDataSource.getConnection(PoolingDataSource.java:142)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:809)

Caused by: java.util.NoSuchElementException: Timeout waiting for idle object
    at org.apache.tomcat.dbcp.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:438)
    at org.apache.tomcat.dbcp.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:348)
    at org.apache.tomcat.dbcp.dbcp2.PoolingDataSource.getConnection(PoolingD

我在另一个问题中读到

数据库已关闭或无法访问。连接池（设置为 100 max active）连接不足。

现在，我想知道如何恢复数据库以初始化连接。

已编辑

以下代码重复了很多次

final InitialContext contextoInicial = new InitialContext();
 final Context contexto = (Context)contextoInicial.lookup("");
 final DataSource ds = (DataSource)contexto.lookup("");
  Connection  conn = ds.getConnection();

如何重用连接并验证是否存在

已编辑

java.sql.SQLException: Cannot get a connection, pool error Timeout waiting for idle object
    at org.apache.tomcat.dbcp.dbcp2.PoolingDataSource.getConnection(PoolingDataSource.java:142)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:753)
    at es.magrama.ayudaapi.servlets.JSON.validaRega(JSON.java:249)
    at es.magrama.ayudaapi.servlets.JSON.doPost(JSON.java:125)
    at es.magrama.ayudaapi.servlets.JSON.doGet(JSON.java:89)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.NoSuchElementException: Timeout waiting for idle object
    at org.apache.tomcat.dbcp.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:438)
    at org.apache.tomcat.dbcp.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:348)
    at org.apache.tomcat.dbcp.dbcp2.PoolingDataSource.getConnection(PoolingDataSource.java:134)
    ... 28 more

标签： javajdbcconnectionconnection-pooling

解决方案

异常显示“连接池已耗尽”问题，因为连接没有关闭并返回到池，或者是因为数据源中定义的最大活动连接小到足以处理系统当前的高负载。我怀疑最大活动计数参数（此处为 maxActive=50）可能会导致在高峰时间处理应用程序负载的连接数量减少。

同样在您的代码中（根据您的评论），我看到您已经初始化数据源很多时间。我建议您将其初始化一次，然后将其用于连接，例如单例对象。

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