Tag Archives: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

[Solved] servlet jump to Blank Page Error: java.lang.ClassNotFoundException: com.mysql.jdbc.

The problem of page blank after servlet jump

Servlet code

report errors

ava.lang.ClassNotFoundException: com.mysql.jdbc.Driver exception

Reason: it has nothing to do with the above code,

The real reason is that the MySQL jar package was not imported into Tomcat. His grandmother found this problem for a long time and almost died

Now let’s show a wave of operation

1. Open Tomcat configuration,

2. Enter the favorite Guide Package link

Everyone’s lib directory is stored in different locations here. Anyway, you need to import the MySQL package into the Lib directory,

If you find that you don’t have this package, we’ll copy and paste it online or copy it in the Maven project

The main reason is that the MySQL package is not imported into tomcat, which leads to such an error

[Solved] JSP Use MySQL database Error: java.lang.classnotfoundexception: com.mysql.jdbc.driver

error

In the JSP of JavaWeb, the MySQL database reports an error, and the com.Mysql.JDBC.Driver cannot be found.

The error log is as follows:

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1858)
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1709)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:264)
	at utils.DBUtils.getConnection(DBUtils.java:14)
	at dao.UserDao.selectAll(UserDao.java:27)
	at servlet.UserServlet.doPost(UserServlet.java:28)
	at servlet.UserServlet.doGet(UserServlet.java:47)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
	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:220)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

reason

Experienced people understand that there is no third-party package added, but it is added in this project, but it is not found.

To view the project structure:

The third-party package is added under external libraries in the following way:

This cannot be taken in Java Web, and the path of jar package cannot be read.

Solution:

Create a libfolder in the Web/WEB-INF directory, and then copy the jar package to this folder to successfully use the database.