From 3b3f3dcd02aba868264fb6ec51701ef8baf8f3f2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=BE=90=E6=B0=B8=E6=B7=B3?= <2678158018@qq.com> Date: Wed, 24 May 2023 23:17:24 +0800 Subject: [PATCH] =?UTF-8?q?=E7=AC=AC=E4=B8=89=E6=AC=A1=E4=BD=9C=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...56\345\272\223\344\275\234\344\270\232.md" | 198 ++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 "18 \345\276\220\346\260\270\346\267\263/20230524 jsp+servlet web\346\223\215\344\275\234\346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" diff --git "a/18 \345\276\220\346\260\270\346\267\263/20230524 jsp+servlet web\346\223\215\344\275\234\346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" "b/18 \345\276\220\346\260\270\346\267\263/20230524 jsp+servlet web\346\223\215\344\275\234\346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" new file mode 100644 index 0000000..2dfb8fd --- /dev/null +++ "b/18 \345\276\220\346\260\270\346\267\263/20230524 jsp+servlet web\346\223\215\344\275\234\346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" @@ -0,0 +1,198 @@ +```java +web类 +import until.Text; + +import javax.servlet.ServletException; +import javax.servlet.annotation.WebServlet; +import javax.servlet.http.HttpServlet; +import javax.servlet.http.HttpServletRequest; +import javax.servlet.http.HttpServletResponse; +import java.io.IOException; +import java.io.PrintWriter; +import java.sql.ResultSet; +import java.sql.SQLException; + +@WebServlet("/Text") + +public class SS extends HttpServlet { + + @Override + protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + System.out.println("这是我数出语句"); + resp.setContentType("Text/html;charset=utf-8"); + PrintWriter out = resp.getWriter(); + out.write("你接受到了一条消息"); + out.write(""); + out.write(""); + //查询 + String sql="select * from studnet"; + ResultSet qure = Text.qure(sql); + try { + while (qure.next()){ + int id = qure.getInt("id"); + String name = qure.getString("name"); + String sex = qure.getString("sex"); + out.write(""+""+""); + } + } catch (SQLException e) { + throw new RuntimeException(e); + } + out.write("
编号姓名性别
"+id+""+name+""+sex+"
"); + //增添 +// String sql1="insert into studnet value(10，'牛蚊疯','妖魔鬼怪大傻叉')"; +// try { +// int insert = Text.insert(sql1); +// out.write("添加成功！"); +// } catch (Exception e) { +// out.write("添加失败！"); +// } + //修改 +// String sql2="update studnet set name='刘文峰' where id=10"; +// try { +// int update = Text.insert(sql2); +// out.write("修改成功！"); +// } catch (Exception e) { +// out.write("修改失败！"); +// } + //删除 +// String sql3="delete from studnet where id=1"; +// try { +// int delete = Text.delete(sql3); +// out.write("删除成功"); +// } catch (Exception e) { +// out.write("删除成功"); +// } + } + + @Override + protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + super.doPost(req, resp); + } +} +``` + +```java +操作数据库类 +package HomeWork.HomeWork0524; + + +import java.sql.*; + +public class Text { + private static final String url="jdbc:mysql:///aaa?useSSL=false&useUnicode=true&characterEncoding=utf8"; + private static final String username="root"; + private static final String password="root"; + static{ + try { + Class.forName("com.mysql.jdbc.Driver"); + } catch (ClassNotFoundException e) { + System.out.println("云心"); + } + } + public static Connection getcon() { + Connection con = null; + try { + con = DriverManager.getConnection(url, username, password); + } catch (SQLException e) { + System.out.println("连接异常'"); + } + return con; + } + public static Connection conget(){ + Connection con = null; + try { + con = DriverManager.getConnection(url, username, password); + } catch (SQLException e) { + System.out.println("连接异常"); + } + return con; + } + public static ResultSet qure(String sql, String...keys) {//查询 + ResultSet res = null; + try { + Connection con = conget(); + PreparedStatement pre = con.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pre.setString((i+1),keys[i]); + } + res = pre.executeQuery(); + } catch (SQLException e) { + throw new RuntimeException(e); + } + return res; + } + public static int insert(String sql,String...keys) {//添加 + int num = 0; + PreparedStatement pre = null; + try { + Connection con = conget(); + pre = con.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pre.setString((i + 1), keys[i]); + } + num = pre.executeUpdate(); + + } catch (SQLException e) { + throw new RuntimeException(e); + } finally { + try { + pre.close(); + conget().close(); + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + return num; + } + public static int update(String sql,String...keys) {//修改 + int num = 0; + PreparedStatement pre = null; + try { + Connection con = conget(); + pre = con.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pre.setString((i + 1), keys[i]); + } + num = pre.executeUpdate(); + pre.close(); + conget().close(); + } catch (SQLException e) { + throw new RuntimeException(e); + } finally { + try { + pre.close(); + conget().close(); + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + return num; + } + public static int delete(String sql,String...keys) {//删除 + int num = 0; + PreparedStatement pre = null; + try { + Connection con = conget(); + pre = con.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pre.setString((i + 1), keys[i]); + } + num = pre.executeUpdate(); + + } catch (SQLException e) { + throw new RuntimeException(e); + } finally { + try { + pre.close(); + conget().close(); + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + + return num; + } +} + +``` + -- Gitee