From ebee8d5c929cc90fcd2d92cfef6f5307216bd71e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E8=8B=8F=E6=B8=85=E5=8D=8E?= Date: Wed, 24 May 2023 21:36:11 +0800 Subject: [PATCH] =?UTF-8?q?20230524=E4=BD=9C=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../20230522 tomcat.md" | 196 ++++++++++++------ ...45\346\225\260\346\215\256\345\272\223.md" | 176 ++++++++++++++++ 2 files changed, 308 insertions(+), 64 deletions(-) create mode 100644 "01 \350\213\217\346\270\205\345\215\216/20230524 \347\275\221\351\241\265\344\277\241\346\201\257\345\206\231\345\205\245\346\225\260\346\215\256\345\272\223.md" diff --git "a/01 \350\213\217\346\270\205\345\215\216/20230522 tomcat.md" "b/01 \350\213\217\346\270\205\345\215\216/20230522 tomcat.md" index cb21c4a..ac49dda 100644 --- "a/01 \350\213\217\346\270\205\345\215\216/20230522 tomcat.md" +++ "b/01 \350\213\217\346\270\205\345\215\216/20230522 tomcat.md" @@ -20,7 +20,7 @@ public class DBUtil { } } public static Connection getConn() throws SQLException { - Connection conn = DriverManager.getConnection("jadc:mysql://localhost:3306/student_db?useSSL=false&charset=utf8", "root", "root"); + Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/student_db?useSSL=false&useUnicode=true&characterEncoding=utf8", "root", "root"); return conn; } public static ResultSet query(String sql,String...keys) throws SQLException { @@ -58,7 +58,6 @@ public class DBUtil { package servlet; import javax.servlet.ServletException; -import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @@ -69,127 +68,196 @@ import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; -@WebServlet("/select") -public class TestTomcat extends HttpServlet { +public class Add extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8"); - PrintWriter out = resp.getWriter(); - Connection conn = DBUtil.getConn(); + resp.setCharacterEncoding("utf-8"); + String sql= "insert into student values (5,'李泰容的狗','女')"; + int i = 0; try { - PreparedStatement pst = conn.prepareStatement("select * from student"); - ResultSet rs = pst.executeQuery(); - out.write(""); - out.write(""); - while (rs.next()){ - out.write(""); - out.write(""); - out.write(""); - } - out.write("
学号姓名性别
"+rs.getInt("stuId")+""+rs.getString("name")+""+rs.getString("sex")+"
"); + i = DBUtil.update(sql); } catch (SQLException e) { - throw new RuntimeException(e); + e.printStackTrace(); } + if(i>0){ + resp.getWriter().write("添加成功"); + }else{ + resp.getWriter().write("添加失败"); + } + + } } + +``` + +```java package servlet; 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.Connection; -import java.sql.PreparedStatement; import java.sql.SQLException; -@WebServlet("/insert") -public class Insert extends HttpServlet { +public class Delete extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { - Connection conn = DBUtil.getConn(); + resp.setContentType("text/html;charset=utf-8"); + resp.setCharacterEncoding("utf-8"); + String sql= "delete from student where ssex = '男'"; + int i = 0; try { - PreparedStatement pst = conn.prepareStatement("insert into student values (5,'李泰容的狗','女')"); - int i = pst.executeUpdate(); - resp.setContentType("text/html;charset=utf-8"); - PrintWriter out = resp.getWriter(); - if (i>0){ - out.write("添加成功"); - }else { - out.write("添加失败"); - } + i = DBUtil.update(sql); } catch (SQLException e) { - throw new RuntimeException(e); + e.printStackTrace(); + } + if(i>0){ + resp.getWriter().write("删除成功"); + }else{ + resp.getWriter().write("删除失败"); } } + + @Override + protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + super.doPost(req, resp); + } } + +``` + +```java package servlet; 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.Connection; -import java.sql.PreparedStatement; +import java.sql.ResultSet; import java.sql.SQLException; -@WebServlet("/update") -public class Set extends HttpServlet { + +public class Select extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8"); - Connection conn = DBUtil.getConn(); + resp.setCharacterEncoding("utf-8"); + resp.getWriter().write("
"); + resp.getWriter().write(""); try { - PreparedStatement pst = conn.prepareStatement("update student set name = '徐明浩' where stuId = 5"); - int i = pst.executeUpdate(); - PrintWriter out = resp.getWriter(); - if (i>0){ - out.write("修改成功"); - }else { - out.write("修改失败"); + String sql="select * from student"; + ResultSet res = DBUtil.query(sql); + while (res.next()){ + int id = res.getInt(1); + String name = res.getString(2); + String sex = res.getString(3); + resp.getWriter().write(""); + resp.getWriter().write(""); + resp.getWriter().write(""); + resp.getWriter().write(""); } + resp.getWriter().write("
id姓名性别
"+id+""+name+""+sex+"
"); + } catch (SQLException e) { throw new RuntimeException(e); } } + + @Override + protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + super.doPost(req, resp); + } } + +``` + +```java package servlet; 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.Connection; -import java.sql.PreparedStatement; import java.sql.SQLException; -@WebServlet("/delete") -public class Delete extends HttpServlet { +public class Update extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8"); - PrintWriter out = resp.getWriter(); - Connection conn = DBUtil.getConn(); + resp.setCharacterEncoding("utf-8"); + String sql= "update student set sname = '徐明浩' where sid = 5"; + int i = 0; try { - PreparedStatement pst = conn.prepareStatement("delete from student where sex = '男'"); - int i = pst.executeUpdate(); - if (i>0){ - out.write("删除成功"); - }else { - out.write("删除失败"); - } + i = DBUtil.update(sql); } catch (SQLException e) { - throw new RuntimeException(e); + e.printStackTrace(); + } + if(i>0){ + resp.getWriter().write("修改成功"); + }else{ + resp.getWriter().write("修改失败"); } } + + @Override + protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { + super.doPost(req, resp); + } } + +``` + +```java + + + + + + add + servlet.Add + + + + delete + servlet.Delete + + + select + servlet.Select + + + update + servlet.Update + + + + + add + /add + + + + delete + /delete + + + + select + /select + + + + update + /update + + ``` diff --git "a/01 \350\213\217\346\270\205\345\215\216/20230524 \347\275\221\351\241\265\344\277\241\346\201\257\345\206\231\345\205\245\346\225\260\346\215\256\345\272\223.md" "b/01 \350\213\217\346\270\205\345\215\216/20230524 \347\275\221\351\241\265\344\277\241\346\201\257\345\206\231\345\205\245\346\225\260\346\215\256\345\272\223.md" new file mode 100644 index 0000000..72b6b75 --- /dev/null +++ "b/01 \350\213\217\346\270\205\345\215\216/20230524 \347\275\221\351\241\265\344\277\241\346\201\257\345\206\231\345\205\245\346\225\260\346\215\256\345\272\223.md" @@ -0,0 +1,176 @@ +```java +import java.sql.*; + +public class DBUtil { + static{ + try { + Class.forName("com.mysql.jdbc.Driver"); + } catch (ClassNotFoundException e) { + throw new RuntimeException(e); + } + } + public static Connection getConn() throws SQLException { + Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/student_db?useSSL=false&useUnicode=true&characterEncoding=utf8", "root", "root"); + return conn; + } + public static ResultSet query(String sql, String...keys) throws SQLException { + Connection conn = getConn(); + PreparedStatement pre = conn.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pre.setString((i+1),keys[i]); + } + ResultSet res = pre.executeQuery(); + return res; + } + public static int update(String sql,String...keys) throws SQLException { + Connection conn = getConn(); + PreparedStatement pre = conn.prepareStatement(sql); + for (int i = 0; i < keys.length; i++) { + pre.setString((i+1),keys[i]); + } + int i = pre.executeUpdate(); + return i; + } + public static void close(Connection conn,PreparedStatement pre,ResultSet res) throws SQLException { + if(res!=null){ + res.close(); + }if(pre!=null){ + pre.close(); + }if(conn!=null){ + conn.close(); + } + } +} + +``` + +```java +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 = "Student", value = "/Student") +public class Student extends HttpServlet { + @Override + protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException{ + resp.setContentType("text/html;charset=utf-8"); + resp.setCharacterEncoding("utf-8"); + resp.getWriter().write(""); + resp.getWriter().write(""); + try { + String sql="select * from student"; + ResultSet res = DBUtil.query(sql); + while (res.next()){ + int id = res.getInt(1); + String name = res.getString(2); + String sex = res.getString(3); + resp.getWriter().write(""); + resp.getWriter().write(""); + resp.getWriter().write(""); + resp.getWriter().write(""); + } + resp.getWriter().write("
id姓名性别
"+id+""+name+""+sex+"
"); + } catch (SQLException e) { + throw new RuntimeException(e); + } + + } + + @Override + protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { + request.setCharacterEncoding("utf-8"); + String id = request.getParameter("id"); + String name = request.getParameter("name"); + String sex = request.getParameter("sex"); + + if (id!=null) { + String sql="insert into student values(?,?,?)"; + response.setContentType("text/html;charset=utf-8"); + try { + int i = DBUtil.update(sql, id, name, sex); + if(i>0){ + response.getWriter().write("添加成功"); + }else{ + response.getWriter().write("添加失败"); + } + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + + String id1 = request.getParameter("id1"); + String name1 = request.getParameter("name1"); + + if (id1!=null) { + String sql="update student set sname=? where sid=? "; + response.setContentType("text/html;charset=utf-8"); + try { + int i = DBUtil.update(sql,name1,id1); + if(i>0){ + response.getWriter().write("修改成功"); + }else{ + response.getWriter().write("修改失败"); + } + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + + String id2 = request.getParameter("id2"); + if (id2!=null) { + String sql="delete from student where sid=? "; + response.setContentType("text/html;charset=utf-8"); + try { + int i = DBUtil.update(sql,id2); + if(i>0){ + response.getWriter().write("删除成功"); + }else{ + response.getWriter().write("删除失败"); + } + } catch (SQLException e) { + throw new RuntimeException(e); + } + } + + } + +} + +``` + +```java + + + + + 测试 + + +

添加学生

+
+ 学号
+ 姓名
+ 性别
+ +
+ +

修改学生信息

+
+ 学号
+ 姓名
+ + +
+ +

删除学生

+
+ 请输入需要删除学生的学号

+ +
+ + +``` + -- Gitee