java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.wsy.dao.Dao.<init>(Dao.java:32)
at com.wsy.dao.Dao.executeQuery(Dao.java:45)
at com.wsy.dao.Dao.check(Dao.java:85)
at com.wsy.iframe.BookLoginIFrame$BookLoginAction.actionPerformed(BookLoginIFrame.java:40)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.wsy.dao.Dao.executeQuery(Dao.java:46)
at com.wsy.dao.Dao.check(Dao.java:85)
at com.wsy.iframe.BookLoginIFrame$BookLoginAction.actionPerformed(BookLoginIFrame.java:40)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

hakey 发表于 2015-6-29 12:21
这个文件，你下载一下。解压后把jar文件放在lib目录下，右键build  path ——>add to build path 即可，再 ...

能问一下，你那目录那一块的背景怎么弄得

可能是jar包有问题！如果是Web程序的话，可能需要把jar包放到服务器程序的lib文件夹里

试一下，别人发给你的jar 包，上一次 我jar 包错了，弄了很久

把mysql-connector-java-5.1.7-bin.jar导入到tomcat的lib目录下面，右键 build path ----->add to build path；搞定！！！！

把jdbc加到项目里，右键 build path ----->add to build path；把mysql-connector-java-5.1.20-bin.jar这个jar包直接拷到lib目录下不就行了.........

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
你没有引mysql的jar包

我想是没连接数据库没传上数据，类和类之间没连接

是不是jar包问题

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver：应该是没有引入mysql驱动导致的

必须把mysql-connector-java-5.1.7-bin.jar导入到tomcat的lib目录下面！

在java项目中，只需要引入mysql-connector-java-5.1.7-bin.jar就可以运行java项目。

在web项目中,当Class.forName("om.mysql.jdbc.Driver");时myeclipse是不会去查找字符串，不会去查找驱动的。所以只需要把mysql-connector-java-5.1.7-bin.jar拷贝到tomcat下lib目录就可以了。
:lol

数据没有添加到数据库

朙兲 发表于 2015-6-30 20:59
可以  给我吧

我先解决一下，解决不了在发给你 :lol

wdd 发表于 2015-6-30 08:32
可以么，会不会太麻烦了

可以  给我吧 1305919293@qq.com

JAVA都配置完的话  看一下你的引用那

朙兲 发表于 2015-6-29 20:24
方便把你东西给我发一份吗，我看看，这个应该是驱动写错了，或者驱动jar包错误 ...

可以么，会不会太麻烦了

方便把你东西给我发一份吗，我看看，这个应该是驱动写错了，或者驱动jar包错误

你的mysql.jar 这个jar包是放到 /WEB-INF/lib  如果是的话，确定下你下载的jar包没有问题，确定下载完全，或者是官方的jar包吗？如果都确定没问题，那么在jar包上右键   Build Path ----> Add to Build Path

从你的异常来看应该不是Web项目吧，那么就应该是jar包没有编译进去。

那些什么放到/WEB-INF/lib这个路径的都是MyEclipse项目，这个会自动编译。

把mysql-connect.jar放入网站名/WEB-INF/lib目录中,重启服务器,试一试

xwdxiaoda 发表于 2015-6-29 17:04
http://blog.csdn.net/huangbiao86/article/details/6428608 看看这个链接

这个我弄过了，也不好使

http://blog.csdn.net/huangbiao86/article/details/6428608 看看这个链接