From 751357e31545b39211d73670f1b038f018b8e8d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=BB=84=E6=B5=A9=E4=B8=9C?= <3187628460@qq.com>
Date: Fri, 26 May 2023 12:05:22 +0800
Subject: [PATCH] =?UTF-8?q?=E7=BD=91=E9=A1=B5=E8=BE=93=E5=85=A5=E6=95=B0?=
 =?UTF-8?q?=E6=8D=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 ...23\345\205\245\344\275\234\344\270\232.md" | 227 ++++++++++++++++++
 1 file changed, 227 insertions(+)
 create mode 100644 "23 \351\273\204\346\265\251\344\270\234/20230524 \347\275\221\351\241\265\350\276\223\345\205\245\344\275\234\344\270\232.md"

diff --git "a/23 \351\273\204\346\265\251\344\270\234/20230524 \347\275\221\351\241\265\350\276\223\345\205\245\344\275\234\344\270\232.md" "b/23 \351\273\204\346\265\251\344\270\234/20230524 \347\275\221\351\241\265\350\276\223\345\205\245\344\275\234\344\270\232.md"
new file mode 100644
index 0000000..4f7df6f
--- /dev/null
+++ "b/23 \351\273\204\346\265\251\344\270\234/20230524 \347\275\221\351\241\265\350\276\223\345\205\245\344\275\234\344\270\232.md"	
@@ -0,0 +1,227 @@
+```java
+//工具类
+
+import java.sql.*;
+import java.sql.SQLException;
+
+public class Tool {
+    private final static String url ="jdbc:mysql://localhost:3306/student_db?useSSL=false&useUnicode=true&characterEncoding=utf8";
+    private final static String name = "root";
+    private final static String password = "root";
+    static {
+        try{
+            Class.forName("com.mysql.jdbc.Driver");
+        }
+        catch (ClassNotFoundException e){
+            e.printStackTrace();
+        }
+    }
+    public static Connection getCon() throws SQLException{
+          Connection conn =   DriverManager.getConnection(url,name,password);
+            return conn;
+
+    }
+    public static ResultSet select(String sql,String ...key) throws SQLException{
+            Connection conn =getCon();
+            PreparedStatement state = conn.prepareStatement(sql);
+            for (int i = 0; i < key.length; i++) {
+                state.setString(i+1,key[i]);
+            }
+           ResultSet res = state.executeQuery();
+            return res;
+    }
+    public static int Update(String url,String ...key) throws SQLException{
+        Connection conn = getCon();
+        PreparedStatement state = conn.prepareStatement(url);
+        for (int i = 0; i < key.length; i++) {
+            state.setString(i+1,key[i]);
+        }
+        int res = state.executeUpdate();
+        return res;
+    }
+}
+//查询
+import javax.servlet.*;
+import javax.servlet.http.*;
+import javax.servlet.annotation.*;
+import java.io.IOException;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+@WebServlet(name = "StudentSelect", value = "/select")
+    public class StudentSelect extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        response.setContentType("text/html;charset=utf-8");
+        String sql = "select * from student";
+        try {
+           ResultSet res = Tool.select(sql);
+            while (res.next()) {
+                int id = res.getInt(1);
+                String name = res.getString(2);
+                String sex = res.getString(3);
+                response.getWriter().write(id + name + sex);
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+
+
+            @Override
+            protected void doPost (HttpServletRequest request, HttpServletResponse response) throws
+            ServletException, IOException {
+                response.setContentType("text/html;charset=utf-8");
+                request.setCharacterEncoding("utf-8");
+
+            }
+        }
+// 添加
+import javax.servlet.*;
+import javax.servlet.http.*;
+import javax.servlet.annotation.*;
+import java.io.IOException;
+import java.sql.SQLException;
+
+@WebServlet(name = "Add",value = "/add")
+public   class StudentAdd extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doGet(req, resp);
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        req.setCharacterEncoding("utf-8");
+        resp.setContentType("text/html;charset=utf-8");
+        String sql ="insert into student values(?,?,?)";
+        String id = req.getParameter("id");
+        String name = req.getParameter("name");
+        String sex = req.getParameter("sex");
+        try {
+            int res = Tool.Update(sql,id,name,sex);
+            if(res>0){
+                resp.getWriter().write("成功");
+            }
+            else {
+                resp.getWriter().write("失败");
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
+//删除
+import javax.servlet.*;
+import javax.servlet.http.*;
+import javax.servlet.annotation.*;
+import java.io.IOException;
+import java.sql.SQLException;
+
+
+
+@WebServlet(name = "Delete",value = "/delete")
+public   class StudentDelete extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doGet(req, resp);
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        req.setCharacterEncoding("utf-8");
+        resp.setContentType("text/html;charset=utf-8");
+        String sql ="Delete from student where id = ?";
+        try {
+            String id = req.getParameter("id");
+            int res = Tool.Update(sql,id);
+            if(res>0){
+                resp.getWriter().write("成功");
+            }
+            else {
+                resp.getWriter().write("失败");
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
+//修改
+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.sql.SQLException;
+@WebServlet(name = "update",value = "/update")
+public class StudentUpdate extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doGet(req, resp);
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        req.setCharacterEncoding("utf-8");
+        resp.setContentType("text/html;charset=utf-8");
+        String sql = "update student set id =? , name=? , sex = ? where id = ?";
+        String changID = req.getParameter("changeID");
+        String name = req.getParameter("name");
+        String sex = req.getParameter("sex");
+        String id = req.getParameter("id");
+        try {
+            int res = Tool.Update(sql,changID,name,sex,id);
+            if(res>0){
+                resp.getWriter().write("成功");
+            }
+            else {
+                resp.getWriter().write("失败");
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
+
+```
+
+```html
+//网页
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Title</title>
+</head>
+<body>
+<h1>查找学生</h1>
+<form action="http://localhost:8080/untitled_war_exploded/select" method="doGet">
+    <input type="submit" name="查询">
+</form>
+<h1>添加学生</h1>
+<form action="http://localhost:8080/untitled_war_exploded/add" method="post">
+  ID  :<input type="text" name="id"><br>
+  name:<input type="text" name="name"><br>
+  sex :<input type="text" name="sex"><br>
+    <input type="submit" name="提交">
+</form>
+<h1>删除学生</h1>
+<form action="http://localhost:8080/untitled_war_exploded/delete" method="post">
+    ID  :<input type="text" name="id"><br>
+    <input type="submit" name="提交">
+</form>
+<h1>修改学生</h1>
+<form action="http://localhost:8080/untitled_war_exploded/update" method="post">
+    需要修改学生的id: <input type="text" name="changeID"><br>
+    新的学生id：<input type="text" name="id"><br>
+    姓名：<input type="text" name="name"><br>
+    性别:<input type="text" name="sex"><br>
+    <input type="submit" name="提交">
+
+</form>
+</body>
+</html>
+```
+
-- 
Gitee