我正在使用Play框架（JAVA）连接到MYSQL . 在与数据库交互时，我会出现间歇性（20％）错误，但异常：
play.api.http.HttpErrorHandlerExceptions $$ anon $ 1：执行异常[[NullPointerException：null]] at play.api.http.HttpErrorHandlerExceptions $ .throwableToUsefulException（HttpErrorHandler.scala：265）〜[play_2.10-2.4.2 . jar：2.4.2] at play.api.http.DefaultHttpErrorHandler.onServerError（HttpErrorHandler.scala：191）〜[play_2.10-2.4.2.jar：2.4.2] at play.api.GlobalSettings $ class.onError（ GlobalSettings.scala：179）[play_2.10-2.4.2.jar：2.4.2] at play.api.DefaultGlobal $ .onError（GlobalSettings.scala：212）[play_2.10-2.4.2.jar：2.4 . 2] at play.api.http.GlobalSettingsHttpErrorHandler.onServerError（HttpErrorHandler.scala：94）[play_2.10-2.4.2.jar：2.4.2] at play.filters.cors.AbstractCORSPolicy $$ anonfun $ 1.applyOrElse（AbstractCORSPolicy .scala：151）[filters-helpers_2.10-2.4.2.jar：2.4.2] at play.filters.cors.AbstractCORSPolicy $$ anonfun $ 1.applyOrElse（AbstractCORSPolicy.scala：150）[filters-helpers_2.10- 2.4.2.jar:2.4.2] scala.concurrent.Future $$ anonfun $ recoverWith $ 1.apply（Future.scala：344）[scala-library-2.1 0.5.jar：na] at scala.concurrent.Future $$ anonfun $ recoverWith $ 1.apply（Future.scala：343）[scala-library-2.10.5.jar：na] at scala.concurrent.impl.CallbackRunnable.run （Promise.scala：32）[scala-library-2.10.5.jar：na] at play.api.libs.iteratee.Execution $ trampoline $ .execute（Execution.scala：70）[play-iteratees_2.10-2.4 .2.jar：2.4.2]在scala.concurrent.impl.CallbackRunnable.executeWithValue（Promise.scala：40）[scala-library-2.10.5.jar：na] scala.concurrent.impl.Promise $ DefaultPromise . tryComplete（Promise.scala：248）[scala-library-2.10.5.jar：na] at scala.concurrent.Promise $ class.tryFailure（Promise.scala：112）[scala-library-2.10.5.jar：na ] scala.concurrent.impl.Promise $ DefaultPromise.tryFailure（Promise.scala：153）[scala-library-2.10.5.jar：na] at play.api.mvc.Filter $$ anon $ 1 $$ anonfun $ apply $ 4 $$ anonfun $ apply $ 1.applyOrElse（Filters.scala：67）[play_2.10-2.4.2.jar：2.4.2] at play.api.mvc.Filter $$ anon $ 1 $$ anonfun $ apply $ 4 $ $ anonfun $在scala.run上应用$ 1.applyOrElse（Filters.scala：61）[play_2.10-2.4.2.jar：2.4.2] time.AbstractPartialFunction.apply（AbstractPartialFunction.scala：33）[scala-library-2.10.5.jar：na] at play.api.libs.iteratee.Iteratee $$ anonfun $ recoverM $ 1.applyOrElse（Iteratee.scala：629） [play-iteratees_2.10-2.4.2.jar：2.4.2] at play.api.libs.iteratee.Iteratee $$ anonfun $ recoverM $ 1.applyOrElse（Iteratee.scala：629）[play-iteratees_2.10-2.4 .2.jar：2.4.2]在scala.runtime.AbstractPartialFunction.apply（AbstractPartialFunction.scala：33）[scala-library-2.10.5.jar：na] scala.util.Failure $$ anonfun $ recover $ 1 . 申请（Try.scala：185）[scala-library-2.10.5.jar：na]在scala.util.Try $ .apply（Try.scala：161）[scala-library-2.10.5.jar：na]在scala.util.Failure.recover（Try.scala：185）[scala-library-2.10.5.jar：na] scala.concurrent.Future $$ anonfun $ recover $ 1.apply（Future.scala：324）[ scala-library-2.10.5.jar：na] at scala.concurrent.Future $$ anonfun $ recover $ 1.apply（Future.scala：324）[scala-library-2.10.5.jar：na] at scala.concurrent .impl.CallbackRunnable.run（Promise.scala：32）[scala-library-2.10.5.jar：na] at akka.d ispatch.BatchingExecutor $ AbstractBatch.processBatch（BatchingExecutor.scala：55）[akka-actor_2.10-2.3.11.jar：na] at akka.dispatch.BatchingExecutor $ BlockableBatch $$ anonfun $ run $ 1.apply $ mcV $ sp（ BatchingExecutor.scala：91）[akka-actor_2.10-2.3.11.jar：na] at akka.dispatch.BatchingExecutor $ BlockableBatch $$ anonfun $ run $ 1.apply（BatchingExecutor.scala：91）[akka-actor_2.10 -2.3.11.jar：na] at akka.dispatch.BatchingExecutor $ BlockableBatch $$ anonfun $ run $ 1.apply（BatchingExecutor.scala：91）[akka-actor_2.10-2.3.11.jar：na] at scala . concurrent.BlockContext $ .withBlockContext（BlockContext.scala：72）[scala-library-2.10.5.jar：na] at akka.dispatch.BatchingExecutor $ BlockableBatch.run（BatchingExecutor.scala：90）[akka-actor_2.10- 2.3.11.jar:na] at akka.dispatch.TaskInvocation.run（AbstractDispatcher.scala：40）[akka-actor_2.10-2.3.11.jar：na] at akka.dispatch.ForkJoinExecutorConfigurator $ AkkaForkJoinTask.exec（AbstractDispatcher .scala：397）[akka-actor_2.10-2.3.11.jar：na] at scala.concurrent.forkjoin.ForkJoinTask.doExec（For kJoinTask.java:260)scala.concurrent.forkjoin.ForkJoinPool上的[scala-library-2.10.5.jar：na] $ WorkQueue.runTask（ForkJoinPool.java:1339）[scala-library-2.10.5.jar：na ]在scala.concurrent.forkjoin.ForkJoinPool.runWorker（ForkJoinPool.java:1979）[scala-library-2.10.5.jar：na] atscala.concurrent.forkjoin.ForkJoinWorkerThread.run（ForkJoinWorkerThread.java:107）[scala-library-2.10.5.jar：na]引起：java.lang.NullPointerException：null at com.mysql.jdbc.ResultSetImpl.checkColumnBounds（ ResultSetImpl.java:826)~ [mysql-connector-java-5.1.27.jar：na] at com.mysql.jdbc.ResultSetImpl.getInt（ResultSetImpl.java:2711）〜[mysql-connector-java-5.1.27 .jar：na] at com.mysql.jdbc.ResultSetImpl.getInt（ResultSetImpl.java:2847）〜[mysql-connector-java-5.1.27.jar：na] at com.zaxxer.hikari.proxy.ResultSetJavassistProxy.getInt （ResultSetJavassistProxy.java）〜[HikariCP-2.3.7.jar：na] at org.hibernate.type.descriptor.sql.IntegerTypeDescriptor $ 2.doExtract（IntegerTypeDescriptor.java:61）〜[hibernate-core-3.6.9.Final .jar：3.6.9.Final]在org.hibernate.type.descriptor.sql.BasicExtractor.extract（BasicExtractor.java:64）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final]在org.hibernate.type.AbstractStandardBasicType.nullSafeGet（AbstractStandardBasicType.java:254）〜[hibernate-core-3.6.9.Final.jar：3.6 . 9.Final]在org.hibernate.type.AbstractStandardBasicType的org.hibernate.type.AbstractStandardBasicType.nullSafeGet（AbstractStandardBasicType.java:250)~ [hibernate-core-3.6.9.Final.jar：3.6.9.Final] . nullSafeGet（AbstractStandardBasicType.java:230）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final] org.hibernate.type.AbstractStandardBasicType.hydrate（AbstractStandardBasicType.java:331)~ [hibernate-core -3.6.9.Final.jar:3.6.9.Final] at org.hibernate.loader.Loader.extractKeysFromResultSet（Loader.java:668)~ [hibernate-core-3.6.9.Final.jar：3.6.9 . 最终]在org.hibernate.loader.doQuery的org.hibernate.loader.Loader.getRowFromResultSet（Loader.java:606）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final] Loader.java:829）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final] org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections（Loader.java:274）〜[hibernate-core-3.6 .9.Final.jar：3.6.9.Final]在org.hibernate.loader.Loader.doList（Loader.java:2542）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final] org.hibernate.loader.Loader.listIgnoreQueryCache（Loader.java:2276）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final] org.hibernate.loader.Loader.list（Loader . java：2271）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final]在org.hibernate.loader.hql.QueryLoader.list（QueryLoader.java:459）〜[hibernate-core-3.6 .9.Final.jar：3.6.9.Final]在org.hibernate.hql.ast.QueryTranslatorImpl.list（QueryTranslatorImpl.java:365）〜[hibernate-core-3.6.9.Final.jar：3.6.9 . 最终]在org.hibernate.impl.SessionImpl的org.hibernate.engine.query.HQLQueryPlan.performList（HQLQueryPlan.java:196）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final] . 列表（SessionImpl.java:1268）〜[hibernate-core-3.6.9.Final.jar：3.6.9.Final]在org.hibernate.impl.QueryImpl.list（QueryImpl.java:102）〜[hibernate-core -3.6.9.Final.jar:3.6.9.Final] at org.hibernate.ejb.QueryImpl.getResultList（QueryImpl.java:246)~ [hibernate-entitymanager-3.6.9.Final.jar：3.6.9 . 最终]在inter.ors上的service.UserService.getSessionById（UserService.java:40）〜[classes /：na] .SecuredAction.call（SecuredAction.java:26）〜[classes /：na]
最初的原因来自Null指针异常
com.mysql.jdbc.ResultSetImpl.checkColumnBounds（ResultSetImpl.java:826）
jar中的方法如下：
/**
802 * Checks if columnIndex is within the number of columns in this result set.
803 *
804 * @param columnIndex
805 * the index to check
806 *
807 * @throws SQLException
808 * if the index is out of bounds
809 */
810 protected final void checkColumnBounds(int columnIndex) throws SQLException {
811 if ((columnIndex < 1)) {
812 throw SQLError.createSQLException(Messages.getString(
813 "ResultSet.Column_Index_out_of_range_low", new Object[] {
814 Constants.integerValueOf(columnIndex),
815 Constants.integerValueOf(this.fields.length) }),
816 SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor()); //$NON-NLS-1$
817 } else if ((columnIndex > this.fields.length)) {
818 throw SQLError.createSQLException(Messages.getString(
819 "ResultSet.Column_Index_out_of_range_high", new Object[] {
820 Constants.integerValueOf(columnIndex),
821 Constants.integerValueOf(this.fields.length) }),
822 SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor()); //$NON-NLS-1$
823 }
824
825 if (this.profileSql || this.useUsageAdvisor) {
826 this.columnUsed[columnIndex - 1] = true;
827 }
828 }
我无法弄清楚失败的原因是什么，因为设置在80％的呼叫上完美运行 .
之后发生此错误
javax.persistence.PersistenceException：org.hibernate.exception.GenericJDBCException：无法打开连接
我试图分别弄清楚它们是否相关，但如果连接不存在且“this”为空，那么代码是否应该在第826行之前断开？
任何人都可以帮助识别错误？提前致谢 .