java.lang.ClassNotFoundException：com.mysql.jdbc.Driver [日食，Tomcat]

Question

我知道这个问题问得太多了，但我还是没弄对。我是运行 Eclipse 上的 Web 应用程序，必须与 mysql 数据库交互。它都在本地主机上的 tomcat 7.0.27 服务器上运行。

尽管我尝试将我的 mysql-connector-java-5.1.21-bin.jar 添加到 java 构建路径，但我仍然得到同样的错误。显然，无论我将它作为外部库还是放在我的 Webcontent/META-INF/lib 文件夹中都没有关系。还尝试了不同版本的连接器（18 和 25）。

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Unknown Source) at ns.Data.getInfo(Data.java:36) at org.apache.jsp.home_jsp._jspService(home_jsp.java:78) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:728) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334) at javax.servlet.http.HttpServlet.service(HttpServlet.java:728) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source)

这是调用驱动程序的 class:

    package ns;
import java.sql.*;
import java.util.*;
public class Data { 

    public Data() {

    };

    public int prova = 4;

    {

    try { 
        Class.forName("com.mysql.jdbc.Driver"); 
        Connection con = DriverManager.getConnection("jdbc:mysql://" + "127.0.0.1" + "/" + "test" + "?" + "user=" + "matt" + "&password=" + "pass"); 
        Statement cmd = con.createStatement();

 // TODO QUERY
        ResultSet rs = cmd.executeQuery("SELECT * FROM carshare.passaggi");


        con.close(); } 
    catch (Exception e) { System.out.println("Errore con DB o Query errata"); 
    e.printStackTrace(); }


}

    public String[] getInfo(String table, String column) {
        String[] values = new String[100];
        int i = 0;
        String temp;

        try { 
            Class.forName("com.mysql.jdbc.Driver"); 
            Connection con = DriverManager.getConnection("jdbc:mysql://" + "127.0.0.1" + "/" + "test" + "?" + "user=" + "matt" + "&password=" + "pass"); 
            Statement cmd = con.createStatement();

     // QUERY DA ESEGUIRE 
            ResultSet rs = cmd.executeQuery("SELECT * FROM carshare."+ table);
        /*              
            while (rs.next()==true) {
                temp = rs.getString(column);
                System.out.print(temp);
                values[i] = temp;
                i++;
            }
            */
            con.close(); } 
        catch (Exception e) { System.out.println("Errore con DB o Query errata"); 
        e.printStackTrace(); }      


        return values;
    }

}

我欢迎任何意见或建议，如果需要，我会要求提供更多信息。

Answer 1

它应该在您的 Webcontent/WEB-INF/lib 文件夹中不 Webcontent/META-INF/库

java.lang.ClassNotFoundException：com.mysql.jdbc.Driver [日食，Tomcat]

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver [Eclipse, Tomcat]

java

mysql

eclipse

tomcat

jdbc