Question

这是我的index.jsp：

的代码

<%@page import="java.sql.SQLException"%>
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.Statement"%>
<%@page import="java.sql.Connection"%>
<%@page import="org.apache.tomcat.jdbc.pool.DataSource"%>
<%@page import="org.apache.tomcat.jdbc.pool.PoolProperties"%>   

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
</head>
<body>
    <div id="query">
        <%
            PoolProperties p = new PoolProperties();
            p.setUrl("jdbc:oracle:thin:@localhost:1521:XE");
            p.setDriverClassName("oracle.jdbc.OracleDriver");
            p.setUsername("scott");
            p.setPassword("tiger");
            p.setMaxActive(100);
            p.setInitialSize(10);

            DataSource datasource = new DataSource();
            datasource.setPoolProperties(p);

            Connection con = null;

            con = datasource.getConnection();
            Statement st = con.createStatement();
            ResultSet rs = st.executeQuery("select 777 from dual");

            while (rs.next()) {
                System.out.println(rs.getString(1));;
            }
            rs.close();
            st.close();
        %>
    </div>
</body>
</html>

这是运行该代码的错误： JSP error 我不明白为什么这个代码运行oracle：

<%
        String dcn = "oracle.jdbc.OracleDriver";
        Class.forName(dcn);
        String serverName = "localhost";
        String portNumber = "1521";
        String sid = "orcl";
        String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":" + sid;
        String username = "scott";
        String password = "tiger";
        Connection conn = DriverManager.getConnection(url, username, password);

        Statement stm = conn.createStatement();
        String query = "SELECT * from emp";
        ResultSet data = stm.executeQuery(query);

        while (data.next()) {
            String number = data.getString("EMPNO");
            String name = data.getString("ENAME");
            %> <%=number%> <%=name%> <br> <%
        }
    %>

尽管我正确地导入了驱动程序。我应该如何在mysql中执行此操作？尝试更换驱动程序，但也没有工作。

MYSQL代码：

<div id="query">
    <%

        String username = "j2ee";
        String password = "j2ee123456";
        String dbName = "testjava";
        String dbHost = "localhost";

        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException msg) {
            out.println("Error loading driver:" + msg.getMessage());
        }
        try {
            String url = "jdbc:mysql://" + dbHost + ":3306/" + dbName;
            Connection Conn = DriverManager.getConnection(url, username, password);
            Statement Stmt = Conn.createStatement();

            String query = "SELECT * FROM example_autoincrement";
            ResultSet rs = Stmt.executeQuery(query);

            while (rs.next()) {
                int numExp = rs.getInt("id");
                String nombre = rs.getString("data");
                %> <%=numExp%> <%=nombre%> <%
            }

        } catch (SQLException e) {
            String err1Msg = e.getMessage();
    %>

    <STRONG><EM>  <%=err1Msg%> </EM></STRONG>

    <%
        }
    %>

我在VPS上的错误加载驱动程序时出错：com.mysql.jdbc.Driver找不到合适的jdbc驱动程序：mysql：// localhost：3306 / testjava

但是我在运行相同代码的XAMPP时没有收到此错误...

Answer 1

解决：将mysql驱动程序放入WEB-INF / lib文件夹后不得不重启tomcat。

无法将J2EE连接到MySQL

1 个答案: