JSP访问数据库

最新推荐文章于 2025-01-31 22:46:00 发布

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最新推荐文章于 2025-01-31 22:46:00 发布

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文章标签： jsp null string 数据库 import books

本文链接：https://blog.youkuaiyun.com/java_cxrs/article/details/4052618

经常看到有人问JSP关于访问数据库的问题

JSP访问数据库的方法其实和servelet访问数据库一样，只是有一些语法上的区别
通常在访问数据库时要注意以下几点：
1.数据库安装时编码应该设置为gb2312避免遇到汉字变成?的问题
2.jsp页面字符编码设置 charset=gb2312 防止页面显示汉字为乱码
3.注意out.printn()输出是否正确。
<%@ page language="java" contentType="text/html; charset=gb2312" pageEncoding="gb2312"%> <%@ page import="java.io.*"%> <%@ page import="java.sql.*"%> <%@ page import="java.util.*"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>DBACCESS</title> </head> <body> <% ResultSet rs = null; Statement stmt = null; Connection conn = null; try { Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost/BookDB?"; String user = "root"; String pw = "123456"; conn = DriverManager.getConnection(url, user, pw); stmt = conn.createStatement(); //stmt.executeUpdate("insert into BOOKS values('999','TOM''TomCAT',44,5,'TOMCAT1',80000)"); rs = stmt.executeQuery("select ID,NAME,TITLE,PRICE from BOOKS"); out.println("<table border=1 width=400>"); while (rs.next()) { String col1 = rs.getString(1); String col2 = rs.getString(2); String col3 = rs.getString(3); float col4 = rs.getFloat(4); out.println("<tr><td>" + col1 + "</td><td>" + col2 + "</td><td>" + col3 + "</td><td>" + col4 + "</td></tr>"); } out.println("</table>"); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } finally { try { if (rs != null) { rs.close(); rs = null; } if (stmt != null) { stmt.close(); stmt = null; } if (conn != null) { conn.close(); conn = null; } } catch (SQLException e) { e.printStackTrace(); } } %> </body> </html>

参考文献：tomcat与JAVAweb开发技术详解