diff --git "a/24 \351\231\210\344\277\212\345\223\262/20230527 \344\275\234\344\270\232.md" "b/24 \351\231\210\344\277\212\345\223\262/20230527 \344\275\234\344\270\232.md" deleted file mode 100644 index 0fc500eb79dfabafb7e0143cf59f91b52102cd5f..0000000000000000000000000000000000000000 --- "a/24 \351\231\210\344\277\212\345\223\262/20230527 \344\275\234\344\270\232.md" +++ /dev/null @@ -1,164 +0,0 @@ -# 作业 - -```html - - - - - - Title - - -
- ID - -
-
-
- ID - name - -
-
-
- ID - -
-
-
- ID - newName - -
- - -``` - -```java -//查询 -import jakarta.servlet.*; -import jakarta.servlet.http.*; -import jakarta.servlet.annotation.*; - -import java.io.IOException; -import java.sql.ResultSet; -import java.sql.SQLException; - -@WebServlet(name = "select", value = "/select") -public class select extends HttpServlet { - @Override - protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - - } - - @Override - protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - response.setCharacterEncoding("utf-8"); - response.setContentType("text/html;charset=utf-8"); - String id1 = request.getParameter("id"); - ResultSet re = Jdbc.select("select * from student where id=?", id1); - try { - while (re.next()) { - String id = re.getString(1); - String name = re.getString(2); - response.getWriter().write(id+" "+name+"
"); - } - } catch (SQLException e) { - throw new RuntimeException(e); - } - } -} -``` - -```java -//添加 -import jakarta.servlet.*; -import jakarta.servlet.http.*; -import jakarta.servlet.annotation.*; - -import java.io.IOException; - -@WebServlet(name = "add", value = "/add") -public class add extends HttpServlet { - @Override - protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - - } - - @Override - protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - response.setCharacterEncoding("utf-8"); - response.setContentType("text/html;charset=utf-8"); - String id = request.getParameter("id"); - String name = request.getParameter("name"); - int i = Jdbc.update("insert into student values(?,?)",id,name); - if (i>0){ - response.getWriter().write("添加成功"); - }else { - response.getWriter().write("添加失败"); - } - } -} -``` - -```java -//删除 -import jakarta.servlet.*; -import jakarta.servlet.http.*; -import jakarta.servlet.annotation.*; - -import java.io.IOException; - -@WebServlet(name = "delete", value = "/delete") -public class delete extends HttpServlet { - @Override - protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - - } - - @Override - protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - response.setCharacterEncoding("utf-8"); - response.setContentType("text/html;charset=utf-8"); - String id = request.getParameter("id"); - int i = Jdbc.update("delete from student where id=?",id); - if (i>0){ - response.getWriter().write("删除成功"); - }else { - response.getWriter().write("删除失败"); - } - } -} -``` - -```java -//修改 -import jakarta.servlet.*; -import jakarta.servlet.http.*; -import jakarta.servlet.annotation.*; - -import java.io.IOException; - -@WebServlet(name = "update", value = "/update") -public class update extends HttpServlet { - @Override - protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - - } - - @Override - protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { - response.setCharacterEncoding("utf-8"); - response.setContentType("text/html;charset=utf-8"); - String id = request.getParameter("id"); - String name = request.getParameter("name"); - int i = Jdbc.update("update student set name=? where id=?",name,id); - if (i>0){ - response.getWriter().write("修改成功"); - }else { - response.getWriter().write("修改失败"); - } - } -} -``` - diff --git "a/24 \351\231\210\344\277\212\345\223\262/20230528 \344\275\234\344\270\232.md" "b/24 \351\231\210\344\277\212\345\223\262/20230528 \344\275\234\344\270\232.md" new file mode 100644 index 0000000000000000000000000000000000000000..f472447c382b7b7e65fdf1b66ccef961584d54ce --- /dev/null +++ "b/24 \351\231\210\344\277\212\345\223\262/20230528 \344\275\234\344\270\232.md" @@ -0,0 +1,275 @@ +```java +package sql; + +import jakarta.servlet.*; +import jakarta.servlet.http.*; +import jakarta.servlet.annotation.*; +import tools.Jdbc; + +import java.io.IOException; + +@WebServlet(name = "Delete", value = "/Delete") +public class Delete extends HttpServlet { + @Override + protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + request.setCharacterEncoding("utf-8"); + response.setContentType("text/html;charset=utf-8"); + String id = request.getParameter("id"); + System.out.println(id); + int i = Jdbc.update("delete from student where id=?", id); + if (i>0){ + response.getWriter().write(""); + }else { + response.getWriter().write(""); + } + } + + @Override + protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + + } +} +``` + +```java +package sql; + +public class Student { + private String id; + private String name; + + public Student() { + } + + public Student(String id, String name) { + this.id = id; + this.name = name; + } + + public String getId() { + return id; + } + + public void setId(String id) { + this.id = id; + } + + public String getName() { + return name; + } + + public void setName(String name) { + this.name = name; + } +} + +``` + +```java +package sql; + +import jakarta.servlet.*; +import jakarta.servlet.http.*; +import jakarta.servlet.annotation.*; +import tools.Jdbc; + +import java.io.IOException; +import java.sql.ResultSet; +import java.sql.SQLException; + +@WebServlet(name = "Update", value = "/Update") +public class Update extends HttpServlet { + @Override + protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + request.setCharacterEncoding("utf-8"); + response.setContentType("text/html;charset=utf-8"); + String id = request.getParameter("id"); + try { + ResultSet re = Jdbc.select("select * from student where id=?", id); + re.next(); + Student s = new Student(re.getString(1), re.getString(2)); + request.setAttribute("student",s); + request.getRequestDispatcher("/update.jsp").forward(request,response); + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + + @Override + protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + + } +} + +``` + +```java +package sql; + +import jakarta.servlet.*; +import jakarta.servlet.http.*; +import jakarta.servlet.annotation.*; +import tools.Jdbc; + +import java.io.IOException; + +@WebServlet(name = "Update2", value = "/Update2") +public class Update2 extends HttpServlet { + @Override + protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + doPost(request, response); + } + + @Override + protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + request.setCharacterEncoding("utf-8"); + response.setContentType("text/html;charset=utf-8"); + String id = request.getParameter("id"); + String name = request.getParameter("name"); + int i = Jdbc.update("update student set name=? where id=?", name, id); + if (i > 0) { + response.getWriter().write(""); + } else { + response.getWriter().write(""); + } + } +} + +``` + +```java +package tools; + +import java.sql.*; + +public class Jdbc { + static { + try { + Class.forName("com.mysql.jdbc.Driver"); + } catch (ClassNotFoundException e) { + throw new RuntimeException(e); + } + } + + //创建连接 + private static Connection conn() { + String url = "jdbc:mysql://localhost:3306/text?useSSL=false&useUnicode=true&characterEncoding=utf8"; + Connection conn = null; + try { + conn = DriverManager.getConnection(url, "root", "sxxddytdn"); + } catch (SQLException e) { + throw new RuntimeException(e); + } + return conn; + } + + //查询 + public static ResultSet select(String sql, String... arr) { + ResultSet re = null; + try { + PreparedStatement pst = conn().prepareStatement(sql); + for (int i = 0; i < arr.length; i++) { + pst.setString((i + 1), arr[i]); + } + re = pst.executeQuery(); + } catch (SQLException e) { + throw new RuntimeException(e); + } + return re; + } + + //增删改 + public static int update(String sql, String... arr) { + try { + PreparedStatement pst = conn().prepareStatement(sql); + for (int i = 0; i < arr.length; i++) { + pst.setString((i + 1), arr[i]); + } + int i = pst.executeUpdate(); + return i; + } catch (SQLException e) { + throw new RuntimeException(e); + } + } +} + +``` + +```jsp +<%@ page import="java.sql.ResultSet" %> +<%@ page import="tools.Jdbc" %><%-- + Created by IntelliJ IDEA. + User: NO.1 + Date: 2023/5/19 + Time: 17:03 + To change this template use File | Settings | File Templates. +--%> +<%@ page contentType="text/html;charset=UTF-8" language="java" %> + + + 学生列表 + + + + + + + + + + + <% + ResultSet re = Jdbc.select("select * from student"); + while (re.next()) { + String id = re.getString(1); + String name = re.getString(2); + %> + + + + + + <% + } + %> +
编号姓名操作
<%=id%><%=name%>修改 删除
+ + + +``` + +```jsp +<%@ page import="sql.Student" %><%-- + Created by IntelliJ IDEA. + User: NO.1 + Date: 2023/5/28 + Time: 20:29 + To change this template use File | Settings | File Templates. +--%> +<%@ page contentType="text/html;charset=UTF-8" language="java" %> + + + 修改 + + +<% + Student s = (Student) request.getAttribute("student"); +%> +
+
+ 姓名:
+ +
+ + + +``` + + + + +