我的GWT项目正在开发模式下工作。编译项目并在 tomcat 服务器上运行它后，我收到以下错误：失败 her500 内部服务器错误 服务器上的调用失败;有关详细信息，请参阅服务器日志
服务器日志：
t-8.0.15webappsPurchaseOrder
15-Nov-2014 20:50:36.375 INFO [localhost-startStop-1] org.apache.catalina.startu
p.HostConfig.deployDirectory Deployment of web application directory C:apache-t
omcat-8.0.15webappsPurchaseOrder has finished in 40 ms
15-Nov-2014 20:50:36.376 INFO [localhost-startStop-1] org.apache.catalina.startu
p.HostConfig.deployDirectory Deploying web application directory C:apache-tomca
t-8.0.15webappsROOT
15-Nov-2014 20:50:36.411 INFO [localhost-startStop-1] org.apache.catalina.startu
p.HostConfig.deployDirectory Deployment of web application directory C:apache-t
omcat-8.0.15webappsROOT has finished in 35 ms
15-Nov-2014 20:50:36.417 INFO [main] org.apache.coyote.AbstractProtocol.start St
arting ProtocolHandler ["http-apr-8080"]
15-Nov-2014 20:50:36.432 INFO [main] org.apache.coyote.AbstractProtocol.start St
arting ProtocolHandler ["ajp-apr-8009"]
15-Nov-2014 20:50:36.433 INFO [main] org.apache.catalina.startup.Catalina.start
Server startup in 2707 ms
15-Nov-2014 20:56:06.865 INFO [localhost-startStop-2] org.apache.catalina.startu
p.HostConfig.deployDirectory Deploying web application directory C:apache-tomca
t-8.0.15webappswar
15-Nov-2014 20:56:18.339 INFO [localhost-startStop-2] org.apache.jasper.servlet.
TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs.
Enable debug logging for this logger for a complete list of JARs that were scan
ned but no TLDs were found in them. Skipping unneeded JARs during scanning can i
mprove startup time and JSP compilation time.
15-Nov-2014 20:56:18.379 INFO [localhost-startStop-2] org.apache.catalina.startu
p.HostConfig.deployDirectory Deployment of web application directory C:apache-t
omcat-8.0.15webappswar has finished in 11,514 ms
java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1295)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1147)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.gwt.sample.purchaseorder.server.database.DatabaseConnector
.connectToServerAndDatabase(DatabaseConnector.java:23)
at com.google.gwt.sample.purchaseorder.server.Controller.allInformationF
romDatabase(Controller.java:24)
at com.google.gwt.sample.purchaseorder.server.PurchaseOrderServiceImpl.g
etListOfPurchaseOrderSortedFromBrands(PurchaseOrderServiceImpl.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:5
61)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(Remot
eServiceServlet.java:265)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(Remot
eServiceServlet.java:305)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(Ab
stractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52
)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(Authentica
torBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAcce
ssLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav
a:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp
11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(
AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pr
ocess(Http11AprProtocol.java:277)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpo
int.java:2407)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoin
t.java:2396)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskTh
read.java:61)
at java.lang.Thread.run(Unknown Source)
java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1295)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1147)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.gwt.sample.purchaseorder.server.database.DatabaseConnector
.connectToServerAndDatabase(DatabaseConnector.java:23)
at com.google.gwt.sample.purchaseorder.server.Controller.allInformationF
romDatabase(Controller.java:24)
at com.google.gwt.sample.purchaseorder.server.PurchaseOrderServiceImpl.g
etListOfPurchaseOrderSortedFromBrands(PurchaseOrderServiceImpl.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:5
61)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(Remot
eServiceServlet.java:265)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(Remot
eServiceServlet.java:305)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(Ab
stractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52
)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(Authentica
torBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAcce
ssLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav
a:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp
11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(
AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pr
ocess(Http11AprProtocol.java:277)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpo
int.java:2407)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoin
t.java:2396)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskTh
read.java:61)
at java.lang.Thread.run(Unknown Source)
java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1295)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1147)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.gwt.sample.purchaseorder.server.database.DatabaseConnector
.connectToServerAndDatabase(DatabaseConnector.java:23)
at com.google.gwt.sample.purchaseorder.server.Controller.allInformationF
romDatabase(Controller.java:24)
at com.google.gwt.sample.purchaseorder.server.PurchaseOrderServiceImpl.g
etListOfPurchaseOrderSortedFromBrands(PurchaseOrderServiceImpl.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:5
61)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(Remot
eServiceServlet.java:265)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(Remot
eServiceServlet.java:305)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(Ab
stractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52
)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(Authentica
torBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAcce
ssLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav
a:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp
11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(
AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pr
ocess(Http11AprProtocol.java:277)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpo
int.java:2407)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoin
t.java:2396)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskTh
read.java:61)
at java.lang.Thread.run(Unknown Source)
java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1295)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClas
sLoaderBase.java:1147)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.gwt.sample.purchaseorder.server.database.DatabaseConnector
.connectToServerAndDatabase(DatabaseConnector.java:23)
at com.google.gwt.sample.purchaseorder.server.Controller.allInformationF
romDatabase(Controller.java:24)
at com.google.gwt.sample.purchaseorder.server.PurchaseOrderServiceImpl.g
etListOfPurchaseOrderSortedFromBrands(PurchaseOrderServiceImpl.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:5
61)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(Remot
eServiceServlet.java:265)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(Remot
eServiceServlet.java:305)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(Ab
stractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52
)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(Authentica
torBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAcce
ssLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav
a:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp
11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(
AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pr
ocess(Http11AprProtocol.java:277)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpo
int.java:2407)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoin
t.java:2396)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskTh
read.java:61)
at java.lang.Thread.run(Unknown Source)
您的 WEB-INF/lib 文件夹中似乎缺少一个必需的 jar 文件，其中包含类"com.microsoft.sqlserver.jdbc.SQLServerDriver"。请将罐子放在所述文件夹中，然后重试。