Question

我正在尝试使用 Java Struts1 建立 Mysql 与数据库的连接。这里是代码片段。我还将 mysql-connector-java-5.0.8-bin.jar 添加到 web-inf / lib 文件夹。同样将其添加到classpath变量中。

import java.sql.DriverManager;

import java.sql.Connection;

import java.sql.SQLException;


public class select {

  public  void connection() {

    System.out.println("-------- MySQL JDBC Connection Testing ------------");

    try {
        Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
        System.out.println("Where is your MySQL JDBC Driver?");
        e.printStackTrace();
        return;
    }.

这是错误讯息。我错过了哪些步骤。请尽快建议。

-------- MySQL JDBC Connection Testing ------------
Where is your MySQL JDBC Driver?
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at Com.Candidjava.select.connection(select.java:14)
    at Com.Candidjava.LoginAction.execute(LoginAction.java:26)
    at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:643)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Unknown Source)

Answer 1

试试这是jdbc连接到mysql数据库的一个例子：

import java.sql.DriverManager;

public class Connection {

private static java.sql.Connection conex = null;

public static java.sql.Connection getConnectionInstance() {
    if (conex == null) {
        try {
            // connection to database
            Class.forName("com.mysql.jdbc.Driver");
            conex = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/databaseName","root",
                    "MySQLPassword");
            return conex;
        } catch (Exception e) {
        }
    }
    return conex;
}

}

确保您已打开安装期间选择的端口。

Answer 2

将mysql-connector-java-5.0.8-bin.jar添加到tomcat安装目录中。当右键单击您的项目并选择构建路径然后库。和内部库Apache Tomcat你应该找到你的连接器jar然后只有你的mysql将工作

mysql连接问题：java.lang.ClassNotFoundException：com.mysql.jdbc.Driver

2 个答案: