HTTP Status 500 - Servlet execution threw an exception

type Exception report
message Servlet execution threw an exception
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Servlet execution threw an exception
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause
java.lang.NoClassDefFoundError: Could not initialize class ru.testScandJavaJsp.model.DatabaseList
    ru.testScandJavaJsp.controller.ReportOut.doGet(ReportOut.java:37)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.75 logs.

C:Javaapache-tomcat-7.0.75bincatalina.bat run
[2017-04-11 09:17:46,884] Artifact testScandJavaJsp:war exploded: Server is not connected. Deploy is not available.
Using CATALINA_BASE:   "C:Users15.Acer.IntelliJIdea2016.3systemtomcatUnnamed_testScandJavaJsp"
Using CATALINA_HOME:   "C:Javaapache-tomcat-7.0.75"
Using CATALINA_TMPDIR: "C:Javaapache-tomcat-7.0.75temp"
Using JRE_HOME:        "c:Program FilesJavajdk1.8.0_121"
Using CLASSPATH:       "C:Javaapache-tomcat-7.0.75binbootstrap.jar;C:Javaapache-tomcat-7.0.75bintomcat-juli.jar"
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version:        Apache Tomcat/7.0.75
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          Jan 18 2017 20:54:42 UTC
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number:         7.0.75.0
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Windows 10
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            10.0
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             c:Program FilesJavajdk1.8.0_121jre
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           1.8.0_121-b13
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Oracle Corporation
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         C:Users15.Acer.IntelliJIdea2016.3systemtomcatUnnamed_testScandJavaJsp
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         C:Javaapache-tomcat-7.0.75
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.config.file=C:Users15.Acer.IntelliJIdea2016.3systemtomcatUnnamed_testScandJavaJspconflogging.properties
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote=
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote.port=1099
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote.ssl=false
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcom.sun.management.jmxremote.authenticate=false
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.rmi.server.hostname=127.0.0.1
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djdk.tls.ephemeralDHKeySize=2048
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=C:Javaapache-tomcat-7.0.75endorsed
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=C:Users15.Acer.IntelliJIdea2016.3systemtomcatUnnamed_testScandJavaJsp
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:Javaapache-tomcat-7.0.75
апр 11, 2017 9:17:47 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.io.tmpdir=C:Javaapache-tomcat-7.0.75temp
апр 11, 2017 9:17:47 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: c:Program FilesJavajdk1.8.0_121bin;C:WINDOWSSunJavabin;C:WINDOWSsystem32;C:WINDOWS;C:ProgramDataOracleJavajavapath;C:Program Files (x86)NVIDIA CorporationPhysXCommon;C:Program Files (x86)InteliCLS Client;C:Program FilesInteliCLS Client;C:Windowssystem32;C:Windows;C:WindowsSystem32Wbem;C:WindowsSystem32WindowsPowerShellv1.0;C:Program FilesIntelIntel(R) Management Engine ComponentsDAL;C:Program FilesIntelIntel(R) Management Engine ComponentsIPT;C:Program Files (x86)IntelIntel(R) Management Engine ComponentsDAL;C:Program Files (x86)IntelIntel(R) Management Engine ComponentsIPT;C:Program Files (x86)AcerabFiles;C:Program Files (x86)Common FilesMDL SharedISIS;C:Program Files (x86)Windows LiveShared;C:WINDOWSsystem32;C:WINDOWS;C:WINDOWSSystem32Wbem;C:WINDOWSSystem32WindowsPowerShellv1.0;C:Program FilesMySQLMySQL Utilities 1.6;C:JavaGitcmd;C:Program Files (x86)SkypePhone;C:Users15.AcerAppDataLocalMicrosoftWindowsApps;;.
апр 11, 2017 9:17:47 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
апр 11, 2017 9:17:48 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
апр 11, 2017 9:17:48 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 554 ms
апр 11, 2017 9:17:48 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
апр 11, 2017 9:17:48 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.75
апр 11, 2017 9:17:48 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
апр 11, 2017 9:17:48 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
апр 11, 2017 9:17:48 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 54 ms
Connected to server
[2017-04-11 09:17:54,831] Artifact testScandJavaJsp:war exploded: Artifact is being deployed, please wait...
апр 11, 2017 9:17:55 PM org.apache.catalina.deploy.WebXml setVersion
WARNING: Unknown version string [3.1]. Default version will be used.
[2017-04-11 09:17:55,726] Artifact testScandJavaJsp:war exploded: Artifact is deployed successfully
[2017-04-11 09:17:55,726] Artifact testScandJavaJsp:war exploded: Deploy took 895 milliseconds
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/test_scand
    at java.sql.DriverManager.getConnection(DriverManager.java:689)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at ru.testScandJavaJsp.model.DatabaseList.a(DatabaseList.java:45)
    at ru.testScandJavaJsp.model.DatabaseList.<clinit>(DatabaseList.java:28)
    at ru.testScandJavaJsp.controller.ReportOut.doGet(ReportOut.java:37)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    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)
апр 11, 2017 9:17:58 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:Javaapache-tomcat-7.0.75webappsmanager
апр 11, 2017 9:17:58 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory C:Javaapache-tomcat-7.0.75webappsmanager has finished in 71 ms

DriverManager.registerDriver(new com.mysql.jdbc.Driver ());