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java.lang.ClassNotFoundException:com.mysql.jdbc.Driver(jar文件已經鏈接並放置在WEB-INF / lib中)

[英]java.lang.ClassNotFoundException: com.mysql.jdbc.Driver (jar file already linked and placed in WEB-INF/lib)

我針對該錯誤找到的解決方案是“通過構建路徑添加jar文件”和“將包含驅動程序的jar文件放入WEB-INF / lib中”(以及類似的提法),但是我已經嘗試了這兩個方法。

回到我的問題。 這是我的代碼:

jsp文件

<?xml version="1.0" encoding="ISO-8859-1" ?>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
    <%@ page import="db.DBAccess" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>Insert title here</title>
</head>
<body>

<jsp:useBean id="dba" class="db.DBAccess"></jsp:useBean>

<jsp:setProperty name="dba" property="selection" value="s" /> 

</body>
</html>

Javabean

package db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DBAccess {

    public DBAccess() {
    }

    private String selection = "";

    public void setSelection(String s) {

        final String driver = "com.mysql.jdbc.Driver";

        String url = "jdbc:mysql://localhost:3306/test";
        String user = "user1";
        String pswd = "user1pswd";

        Connection con = null;
        Statement stmt = null;

        try {
            // initialize connection
            Class.forName(driver);
            con = DriverManager.getConnection(url, user, pswd);
            stmt = con.createStatement();
            // execute select
            ResultSet results = stmt.executeQuery("SELECT * FROM t");
            results.next();
            selection =  results.getString(1);
            // close connection
            stmt.close();
            con.close();
        } catch (ClassNotFoundException cnfe) {
            System.out.println(cnfe.toString());
        } catch (SQLException e) {
            System.out.println(e.toString());
            }

    }
}

t的內容是帶有標簽“字符串”和內容“ hello world”的一列

即使我正確鏈接了jar文件,為什么仍會收到此異常?

您是否將jar文件插入到Webinf的lib文件夾中?

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