如图，红框里的是我新加的一条语句，加了之后就无法调试访问了，这是为什么呢，一般会是什么原因？我是菜鸟。。

这个要看test_sql这个类的get_username的方法怎么写的，其中是不是有错误，丢出了什么异常，单步调试运行下。

@caozhy

我后来做了个测试

这样的方法也会报错，应该是那一句的问题吧，我应该怎么解决呢？？

这是connection（）方法

你没给出get_username这个方法，我们怎么判断哦，既然加了这句话有错说明该方法或该方法的调用的底层方法有错

浏览器控制台报什么错呢？还有，这个类是哪里的？引用了嘛？

这是控制台的信息，，，，看不懂

2016-7-26 15:49:23 org.apache.catalina.core.AprLifecycleListener init
警告: The APR based Apache Tomcat Native library failed to load. The error reported was [D:\Develop\TomCat\apache-tomcat-7.0.70\bin\tcnative-1.dll: Can't load AMD 64-bit .dll on a IA 32-bit platform]
java.lang.UnsatisfiedLinkError: D:\Develop\TomCat\apache-tomcat-7.0.70\bin\tcnative-1.dll: Can't load AMD 64-bit .dll on a IA 32-bit platform
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1807)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1732)
at java.lang.Runtime.loadLibrary0(Runtime.java:823)
at java.lang.System.loadLibrary(System.java:1028)
at org.apache.tomcat.jni.Library.(Library.java:42)
at org.apache.tomcat.jni.Library.initialize(Library.java:178)
at org.apache.catalina.core.AprLifecycleListener.init(AprLifecycleListener.java:201)
at org.apache.catalina.core.AprLifecycleListener.isAprAvailable(AprLifecycleListener.java:109)
at org.apache.catalina.connector.Connector.setProtocol(Connector.java:592)
at org.apache.catalina.connector.Connector.(Connector.java:66)
at org.apache.catalina.startup.ConnectorCreateRule.begin(ConnectorCreateRule.java:62)
at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1282)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:501)
at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:179)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1343)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2756)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:647)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1205)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1555)
at org.apache.catalina.startup.Catalina.load(Catalina.java:616)
at org.apache.catalina.startup.Catalina.load(Catalina.java:667)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:253)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:427)
2016-7-26 15:49:24 org.apache.tomcat.util.digester.SetPropertiesRule begin
警告: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:ZMZB_Login1.0' did not find a matching property.
2016-7-26 15:49:24 org.apache.tomcat.util.digester.SetPropertiesRule begin
警告: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:Hello_JSP' did not find a matching property.
2016-7-26 15:49:24 org.apache.tomcat.util.digester.SetPropertiesRule begin
警告: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:Hello_sqlite' did not find a matching property.
2016-7-26 15:49:24 org.apache.tomcat.util.digester.SetPropertiesRule begin
警告: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:ZMZB_SQL1.0' did not find a matching property.
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Server version: Apache Tomcat/7.0.70
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Server built: Jun 15 2016 16:27:45 UTC
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Server number: 7.0.70.0
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: OS Name: Windows 7
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: OS Version: 6.1
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Architecture: x86
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Java Home: D:\Develop\Java\jdk1.6\jre
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: JVM Version: 1.6.0_33-b05
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: JVM Vendor: Sun Microsystems Inc.
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: CATALINA_BASE: D:\Develop\WEB.metadata.plugins\org.eclipse.wst.server.core\tmp0
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: CATALINA_HOME: D:\Develop\TomCat\apache-tomcat-7.0.70
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dcatalina.base=D:\Develop\WEB.metadata.plugins\org.eclipse.wst.server.core\tmp0
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dcatalina.home=D:\Develop\TomCat\apache-tomcat-7.0.70
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dwtp.deploy=D:\Develop\WEB.metadata.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Djava.endorsed.dirs=D:\Develop\TomCat\apache-tomcat-7.0.70\endorsed
2016-7-26 15:49:24 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dfile.encoding=GBK
2016-7-26 15:49:24 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["http-bio-8888"]
2016-7-26 15:49:24 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["ajp-bio-8009"]
2016-7-26 15:49:24 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 1709 ms
2016-7-26 15:49:24 org.apache.catalina.core.StandardService startInternal
信息: Starting service Catalina
2016-7-26 15:49:24 org.apache.catalina.core.StandardEngine startInternal
信息: Starting Servlet Engine: Apache Tomcat/7.0.70
2016-7-26 15:49:25 org.apache.tomcat.websocket.server.WsSci onStartup
信息: JSR 356 WebSocket (Java WebSocket 1.1) support is not available when running on Java 6. To suppress this message, run Tomcat on Java 7, remove the WebSocket JARs from $CATALINA_HOME/lib or add the WebSocket JARs to the tomcat.util.scan.DefaultJarScanner.jarsToSkip property in $CATALINA_BASE/conf/catalina.properties. Note that the deprecated Tomcat 7 WebSocket API will be available.
2016-7-26 15:49:25 org.apache.catalina.util.SessionIdGeneratorBase createSecureRandom
信息: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [280] milliseconds.
2016-7-26 15:49:26 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-bio-8888"]
2016-7-26 15:49:26 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["ajp-bio-8009"]
2016-7-26 15:49:26 org.apache.catalina.startup.Catalina start
信息: Server startup in 1642 ms
java.lang.ClassNotFoundException: org.sqlite.JDBC