diff --git "a/14 \345\256\213\345\256\217\346\211\254/20230522\345\205\263\344\272\216servlet\347\232\204\344\275\234\344\270\232.md" "b/14 \345\256\213\345\256\217\346\211\254/20230522\345\205\263\344\272\216servlet\347\232\204\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..5cafc96367f6b44f478cabea3b2e518992fe6828
--- /dev/null
+++ "b/14 \345\256\213\345\256\217\346\211\254/20230522\345\205\263\344\272\216servlet\347\232\204\344\275\234\344\270\232.md"	
@@ -0,0 +1,182 @@
+```java
+import java.sql.*;
+public class Jbdc {
+    private static final String url="jdbc:mysql:///student_db?useSSL=false&useUnicode=true&characterEncoding=utf8";
+    private static final String username="root";
+    private static final String psw="root";
+    public static Connection link() throws ClassNotFoundException, SQLException {
+        Class.forName("com.mysql.cj.jdbc.Driver");
+        Connection conn = DriverManager.getConnection(url, username, psw);
+        return conn;
+    }
+    public static int currencyUpdate(String sql,String ...keys) throws SQLException, ClassNotFoundException {
+        Connection conn = link();
+        PreparedStatement prs = conn.prepareStatement(sql);
+        for (int i = 0; i < flop.length; i++) {
+            prs.setString((i+1),keys[i]);
+        }
+        int i = prs.executeUpdate();
+        return i;
+    }
+    public static int delete(String sql,String ...keys) throws SQLException, ClassNotFoundException {
+        int i = currencyUpdate(sql, keys);
+        return i;
+    }
+    public static int modify(String sql,String ...keys) throws SQLException, ClassNotFoundException {
+        int i = currencyUpdate(sql, keys);
+        return i;
+    }
+    public static int add(String sql,String ...keys) throws SQLException, ClassNotFoundException {
+        int i = currencyUpdate(sql, keys);
+        return i;
+    }
+    public static ResultSet Query(String sql,String ...keys) throws SQLException, ClassNotFoundException {
+        Connection conn = link();
+        PreparedStatement prs = conn.prepareStatement(sql);
+        for (int i = 0; i < flop.length; i++) {
+            prs.setString((i+1),keys[i]);
+        }
+        ResultSet rs = prs.executeQuery();
+        return rs;
+    }
+}
+//查找
+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.ResultSet;
+import java.sql.SQLException;
+@WebServlet("/select")
+public class select extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        resp.setContentType("text/html;charset=utf-8");
+        resp.setCharacterEncoding("utf-8");
+        try {
+            String sql ="select * from student";
+            ResultSet rs = Jbdc.Query(sql);
+            while (rs.next()){
+                int id = rs.getInt("id");
+                String name = rs.getString("name");
+                String sex = rs.getString("sex");
+                resp.getWriter().write(id+" "+name+" "+sex+"<br/>");
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doPost(req, resp);
+    }
+}
+//添加
+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("/add")
+public class Add extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        resp.setContentType("text/html;charset=utf-8");
+        resp.setCharacterEncoding("utf-8");
+        try {
+            String sql ="insert into student values (?,?,?)";
+            int add = Jbdc.add(sql, "4", "小叶", "男");
+            if (add>0){
+                resp.getWriter().write("成功");
+            }else {
+                resp.getWriter().write("失败");
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doPost(req, resp);
+    }
+}
+//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("/modify")
+public class Modify extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        resp.setContentType("text/html;charset=utf-8");
+        resp.setCharacterEncoding("utf-8");
+        try {
+            String sql ="update student set sex=? where id=?";
+            int add = Jbdc.add(sql, "女","2");
+            if (add>0){
+                resp.getWriter().write("成功");
+            }else {
+                resp.getWriter().write("失败");
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doPost(req, resp);
+    }
+}
+//删除
+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("/delete")
+public class Delete extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        resp.setContentType("text/html;charset=utf-8");
+        resp.setCharacterEncoding("utf-8");
+        try {
+            String sql ="delete from student where id=?";
+            int add = Jbdc.add(sql, "1");
+            if (add>0){
+                resp.getWriter().write("成功");
+            }else {
+                resp.getWriter().write("失败");
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        super.doPost(req, resp);
+    }
+}
+```
+