From 4aa4becc8c88d2a29bf2ab77dc61d09644e34e59 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=AE=98=E6=96=87=E8=AF=9A?= <3287861587@qq.com> Date: Thu, 25 May 2023 00:19:33 +0800 Subject: [PATCH 1/2] zuoye --- .../20230524 Tomcat .md" | 148 ++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 "08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" diff --git "a/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" "b/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" new file mode 100644 index 0000000..63534cc --- /dev/null +++ "b/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" @@ -0,0 +1,148 @@ +### 增删改查 + +~~~ java +package servlet; + +import java.sql.*; + +public class Gju { + public static String url="jdbc:mysql:///student_db?useSSL=false&characterEncoding=utf8"; + public static String username="root"; + public static String password="root"; + static { + try { + Class.forName("com.mysql.jdbc.Driver"); + } catch (ClassNotFoundException e) { + System.out.println("驱动包异常"); + } + } + + public static Connection getconn(){ + Connection conn = null; + try { + DriverManager.getConnection(url,username,password); + } catch (SQLException e) { + e.printStackTrace(); + } + return conn; + } + // 查 + public static ResultSet query(String sql, String ...keys){ + //获取链接对象 + Connection conn = getconn(); + ResultSet rst = null; + try { + PreparedStatement pst = conn.prepareStatement(sql); + + for (int i = 0; i < keys.length; i++) { + pst.setString((i+1),keys[i]); + } + + //执行SQL语句 + rst = pst.executeQuery(); + } catch (SQLException e) { + System.out.println("执行查询异常"); + e.printStackTrace(); + } + return rst; + } + // 增 + public static int insert(String sql,String ...keys){ + Connection conn = getconn(); + int num=0; + try { + PreparedStatement pst = conn.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pst.setString((i+1),keys[i]); + } + num = pst.executeUpdate(); + } catch (SQLException e) { + e.printStackTrace(); + } + return num; + } + +} + +~~~ + +### 测试类 + +### 查 + +~~~ java +import javax.jws.WebService; +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("/mx") +public class SelectTest extends HttpServlet { + @Override + protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + resp.setContentType("text/html;charset=utf-8"); + resp.setCharacterEncoding("utf-8"); + PrintWriter wr = resp.getWriter(); + String sql="select * from studen"; + ResultSet que =Select.query(sql); + wr.write(""); + wr.write("编号,姓名,性别"); + try { + while (que.next()){ + String id=que.getString(1); + String name=que.getString(2); + String sex= que.getString(3); + wr.write(id+"----"+name+"----"+sex); + } + } catch (SQLException e) { + e.printStackTrace(); + } + wr.write("
"); + } + + @Override + protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + super.doPost(req, resp); + } +} + +~~~ + +### 增 + +~~~ java +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; + +@WebServlet("/mx") +public class ZenTest extends HttpServlet { + @Override + protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + resp.setContentType("text/html;charset=utf-8"); + resp.setCharacterEncoding("utf-8"); + PrintWriter wr = resp.getWriter(); + String sql="insert into studen values(10,'叶子豪')"; + try { + int i = Zen.query(sql); + wr.write("添加成功"); + } catch (Exception e) { + wr.write("添加失败"); + } + @Override + protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + super.doPost(req, resp); + } + } +~~~ + -- Gitee From cbbd04f35779cb3584452b5faa93bcc65c1b04e8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=AE=98=E6=96=87=E8=AF=9A?= <3287861587@qq.com> Date: Thu, 25 May 2023 00:23:21 +0800 Subject: [PATCH 2/2] =?UTF-8?q?=E4=BD=9C=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- "08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git "a/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" "b/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" index 63534cc..57a141b 100644 --- "a/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" +++ "b/08 \345\256\230\346\226\207\350\257\232/20230524 Tomcat .md" @@ -5,7 +5,7 @@ package servlet; import java.sql.*; -public class Gju { +public class Select { public static String url="jdbc:mysql:///student_db?useSSL=false&characterEncoding=utf8"; public static String username="root"; public static String password="root"; -- Gitee