工程目录：
bean:通过bean传递servlet中的数据给dao
package Bean;
public class bean {
private String words;
private int id;
public String getWords() {
return words;
}
public void setWords(String words) {
this.words = words;
}
public bean(String words)
{
this.words=words;
}
public bean() {
}
public bean(int id, String words)
{
this.id=id;
this.words=words;
}
public int getId() {
// TODO Auto-generated method stub
return this.id;
};
}
bean
dao:实现对数据库的操作
package Dao;
import java.sql.ResultSet;
import java.sql.SQLDataException;
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.Statement;
import Util.DBUtil;
import Bean.bean;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class dao{
private DBUtil dbutil=new DBUtil();
public dao() {};
public boolean cook(bean b) {
boolean f=false;
String sql="insert into words(id,words) values(?,?)";
Connection conn = null;
Statement state=null;
PreparedStatement ps=null;
ResultSet rs=null;
int cnt=0;
try {
conn = DBUtil.getConnection();
//state=conn.createStatement();
ps=conn.prepareStatement(sql);
ps.setString(1, null);
ps.setString(2, b.getWords());
cnt=ps.executeUpdate();
if(cnt>0) f=true;
}catch(Exception e) {
e.printStackTrace();
}finally {
DBUtil.close(conn);
}
return f;
}
public boolean discard(int id) {
boolean f=false;
String sql="delete from words where id='"+id+"'";
Connection conn = null;
//Statement state=null;
PreparedStatement ps=null;
ResultSet rs=null;
int cnt=0;
try {
conn = DBUtil.getConnection();
//state=conn.createStatement();
ps=conn.prepareStatement(sql);
ps.executeUpdate();
//state.executeUpdate(sql);
cnt=ps.executeUpdate();
if(cnt>0) f=true;
}catch(Exception e) {
e.printStackTrace();
}finally {
DBUtil.close(conn);
DBUtil.close(ps);
//DBUtil.close(state);
}
return f;
}
public boolean add(bean b) {
boolean f=false;
String sql="update words set id='"+b.getId()+"', words='"+b.getWords()+"' where id='"+b.getId()+"'";
Connection conn = null;
Statement state=null;
PreparedStatement ps=null;
//ResultSet rs=null;
int cnt=0;
try {
conn = DBUtil.getConnection();
ps=conn.prepareStatement(sql);
ps.executeUpdate();
cnt=ps.executeUpdate(sql);
if(cnt>0) f=true;
}catch(Exception e) {
e.printStackTrace();
}finally {
DBUtil.close(conn);
DBUtil.close(ps);
DBUtil.close(state);
}
return f;
}
}
dao
servlet:接收来自前端的数据，并利用dao对数据库进行操作
package servlet;
import Bean.bean;
import Util.DBUtil;
import Dao.dao;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet
*/
@WebServlet("/Servlet")
public class Servlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Servlet() {
super();
// TODO Auto-generated constructor stub
}
private void cook(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
request.setCharacterEncoding("UTF-8");
String words=request.getParameter("words");
dao dao=new dao();
bean b=new bean(words);
try {
if(dao.cook(b)) {
request.setAttribute("messqge","成功上桌");
request.getRequestDispatcher("success.jsp").forward(request, response);
}
else {
request.setAttribute("messqge","上桌失败");
request.getRequestDispatcher("defeat.jsp").forward(request, response);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void discard(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
request.setCharacterEncoding("UTF-8");
int id=Integer.parseInt(request.getParameter("id"));
dao dao=new dao();
try {
if(dao.discard(id)) {
request.setAttribute("messqge","成功丢弃");
request.getRequestDispatcher("success.jsp").forward(request, response);
}
else {
request.setAttribute("messqge","丢弃失败");
request.getRequestDispatcher("defeat.jsp").forward(request, response);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void add(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
request.setCharacterEncoding("UTF-8");
int id=Integer.parseInt(request.getParameter("id"));
String words=request.getParameter("words");
dao dao=new dao();
bean b=new bean(id,words);
try {
if(dao.add(b)) {
request.setAttribute("messqge","成功加料");
request.getRequestDispatcher("success.jsp").forward(request, response);
}
else {
request.setAttribute("messqge","加料失败");
request.getRequestDispatcher("defeat.jsp").forward(request, response);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("utf-8");
String method=request.getParameter("method");
if("cook".equals(method))
{
cook(request,response);
}
else if("discard".equals(method)) {
discard(request,response);
}
else if("add".equals(method)) {
add(request,response);
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
servlet
DBUtil:链接工具
package Util;
import java.sql.*;
public class DBUtil {
public static Connection getConnection() throws ClassNotFoundException, SQLException {
Connection connection = null;//连接数据库
Statement stmt = null;//Statement 对象用于将 SQL 语句发送到数据库中。
ResultSet rs = null;
//1. 导入驱动jar包
//2.注册驱动
Class.forName("com.mysql.cj.jdbc.Driver");
// 好像要设置时区？？
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/Mydea?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT", "root", "200214");
return connection;
}
public static void close(Connection connection) {
try {
if (connection != null) {
connection.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void close(PreparedStatement preparedStatement) {
try {
if (preparedStatement != null) {
preparedStatement.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void close(ResultSet resultSet) {
try {
if (resultSet != null) {
resultSet.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void close(Statement st) {
try {
if (st != null) {
st.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void close(Statement state, Connection connection) {
try {
if (connection != null) {
connection.close();
}
if (state != null)
{
state.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void close(ResultSet rs, Statement state, Connection conn) {
try {
if (conn != null) {
conn.close();
}
if (state != null)
{
state.close();
}
if(rs != null)
{
rs.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
DBUtil
mune.jsp 菜单
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>鸡汤大全</title>
</head>
<body>
<p style="text-align:center;font-size:20px" >
<input type="button" value="开始喝汤" onclick="location.href='start.jsp'" /><br>
<input type="button" value="我要煮汤" onclick="location.href='cook.jsp'" /><br>
<input type="button" value="我要倒汤" onclick="location.href='discard.jsp'" /><br>
<input type="button" value="给汤加料" onclick="location.href='add.jsp'" /><br>
<input type="button" value="我要找汤" onclick="location.href='find.jsp'" /><br>
<br>
</p>
</body>
</html>
mune
cook.jsp 增加页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>煮汤环节</title>
</head>
<body>
<%
Object message = request.getAttribute("message");
if (message != null && !"".equals(message)) {
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>"); //弹出对话框
</script>
<%
}
%>
<h3 align="center" >开始煮汤</h2>
<form action="Servlet?method=cook" method="post">
<table align="center" width=0 border="2">
<td><input type="text" name="words" wideth="600"></td>
<td> <button type="submit">上桌</button> </td>
<td><input type="button" value="蒜啦蒜啦" onclick="location.href='mune.jsp'" /></td>
</table>
</form>
</body>
</html>
cook
discard.jsp 删除页面，利用按钮控制删除的数据
<%@ page import="Util.DBUtil"%>
<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.SQLException" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<%
Object message = request.getAttribute("message");
if (message != null && !"".equals(message)) {
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>"); //弹出对话框
</script>
<%
}
%>
<body>
<form action="Servlet?method=discard" align="center" method="post">
<table align="center" border="1">
<tr>
<td align="center">
id
</td>
<td align="center">
鸡汤
</td>
<td align="center">
删除
</td>
</tr>
<%
Connection conn=DBUtil.getConnection();
PreparedStatement pre=null;
ResultSet in=null;
try{
// 按照添加时间排序：：
pre=conn.prepareStatement("select * from words");
in = pre.executeQuery();
while(in.next()){
%>
<tr>
<td><%=in.getInt(1)%></td>
<td><%=in.getString(2)%></td>
<td><button type="submit" name="id" value="<%=in.getString(1)%>"> 删除</button></td>>
</tr>
<%
}
} catch (SQLException e) {
throw new RuntimeException(e);
}finally {
conn.close();
pre.close();
in.close();
}
%>
</table>
<td><input type="button" value="蒜啦蒜啦" onclick="location.href='mune.jsp'" /></td>
</form>
</body>
</html>
discard
find.jsp 查询页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>找汤</title>
</head>
<body>
<form action=finded.jsp method="post" align="center">
<tr>
<select name="se">
<option value="1">id</option>
<option value="2">鸡汤</option>
</select>
<input type="text" name="lect"></input>
</tr>
<tr>
<button type="submit">开找</button>
<td><input type="button" value="蒜啦蒜啦" onclick="location.href='mune.jsp'" /></td>
</tr>
</form>
</body>
</html>
find
finded.jsp 输出查询结果
<%@ page import="Util.DBUtil"%>
<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.SQLException" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>找到了啥</title>
</head>
<%
Object message = request.getAttribute("message");
if (message != null && !"".equals(message)) {
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>"); //弹出对话框
</script>
<%
}
%>
<body>
<h3 align="center">找到了啥</h3>
<form align="center" >
<table align="center" border="1">
<tr>
<td align="center">
id
</td>
<td align="center">
鸡汤
</td>
</tr>
<%
request.setCharacterEncoding("utf-8");
int id=Integer.parseInt(request.getParameter("se"));
String lect=request.getParameter("lect");
if(id==1){
Connection conn=DBUtil.getConnection();
PreparedStatement pre=null;
ResultSet in=null;
try{
// 按照添加时间排序：：
pre=conn.prepareStatement("select * from words");
in = pre.executeQuery();
while(in.next()){
if(lect.equals(in.getString(1))){
%>
<tr>
<td><%=in.getInt(1)%></td>
<td><%=in.getString(2)%></td>
</tr>
<%
}
}
} catch (SQLException e) {
throw new RuntimeException(e);
}finally {
conn.close();
pre.close();
in.close();
}
}
%>
<%
if(id==2)
{
Connection conn=DBUtil.getConnection();
PreparedStatement pre=null;
//Statement
ResultSet in=null;
int cnt=0;
try{
// 按照添加时间排序：：
pre=conn.prepareStatement("select * from words where words like '%"+lect+"%'");
String sql="select * from words where words like '%"+lect+"%'";
conn.createStatement();
in = pre.executeQuery(sql);
%>
<%
while(in.next()) {
%>
<tr>
<td><%=in.getInt(1)%></td>
<td><%=in.getString(2)%></td>
</tr>
<%
}
} catch (SQLException e) {
throw new RuntimeException(e);
}finally {
conn.close();
pre.close();
in.close();
}
}
%>
</table>
<p align="center">
<input type="button" value="O.o" onclick="location.href='mune.jsp'" />
<input type="button" value="T.T" onclick="location.href='find.jsp'" />
</p>
</body>
</html>
finded
add.jsp 修改页面，利用按钮控制修改的数据
<%@ page import="Util.DBUtil"%>
<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.SQLException" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>料加给谁</title>
</head>
<%
Object message = request.getAttribute("message");
if (message != null && !"".equals(message)) {
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>"); //弹出对话框
</script>
<%
}
%>
<body>
<h3 align="center"> 加料咯</h3>
<form action="add1.jsp" align="center" method="post">
<table align="center" border="1">
<tr>
<td align="center">
id
</td>
<td align="center">
鸡汤
</td>
<td align="center">
加料
</td>
</tr>
<%
Connection conn=DBUtil.getConnection();
PreparedStatement pre=null;
ResultSet in=null;
try{
// 按照添加时间排序：：
pre=conn.prepareStatement("select * from words");
in = pre.executeQuery();
while(in.next()){
%>
<tr>
<td><%=in.getInt(1)%></td>
<td><%=in.getString(2)%></td>
<td><button type="submit" name="id" value="<%=in.getString(1)%>">加料</button></td>>
</tr>
<%
}
} catch (SQLException e) {
throw new RuntimeException(e);
}finally {
conn.close();
pre.close();
in.close();
}
%>
</table>
<td><input type="button" value="蒜啦蒜啦" onclick="location.href='mune.jsp'" /></td>
</form>
</body>
</html>
add
add1.jsp 录入修改的值
<%@ page import="Util.DBUtil"%>
<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.SQLException" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>给汤加点料</title>
</head>
<%
Object message = request.getAttribute("message");
if (message != null && !"".equals(message)) {
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>"); //弹出对话框
</script>
<%
}
%>
<body>
<form action="Servlet?method=add" align="center" method="post">
<table align="center" border="1">
<tr>
<td align="center">
id
</td>
<td align="center">
鸡汤
</td>
</tr>
<%
int id=Integer.parseInt(request.getParameter("id"));
Connection conn=DBUtil.getConnection();
PreparedStatement pre=null;
ResultSet in=null;
try{
// 按照添加时间排序：：
pre=conn.prepareStatement("select * from words");
in = pre.executeQuery();
while(in.next()){
if(id==in.getInt(1)){
%>
<tr>
<td><%=in.getInt(1)%></td>
<td><%=in.getString(2)%></td>
</tr>
<tr>
<td><input name="id" value="<%=in.getString(1)%>"></button></td>>
<td><input type="text" name="words" ></td>
</tr>
<%
}
}
} catch (SQLException e) {
throw new RuntimeException(e);
}finally {
conn.close();
pre.close();
in.close();
}
%>
</table>
<button type="submit">上桌</button>
<td><input type="button" value="蒜啦蒜啦" onclick="location.href='mune.jsp'" /></td>
</form>
</body>
</html>
add1
start.jsp 随机输出一条数据，利用random实现
<%@ page import="Util.DBUtil" %>
<%@ page import="java.sql.Connection" %>
<%@ page import="java.math.*" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.SQLException" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%--<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>--%>
<html>
<head>
<title>浏览</title>
</head>
<body>
<h2 align="center" >------------------------------------------------------------------</h2><br>
<table align="center" border="1">
<%
int random=(int)(1+Math.random()*5);
Connection connection= DBUtil.getConnection();
PreparedStatement preparedStatement=null;
ResultSet in=null;
try{
// 按照添加时间排序：：
preparedStatement=connection.prepareStatement("select * from Words");
in = preparedStatement.executeQuery();
while(in.next()){
if(in.getInt(1)==random){
%>
<tr>
<td><%=in.getString(1)%></td>
<td><%=in.getString(2)%></td>
</tr>
<%
}
}
}catch (SQLException e) {
throw new RuntimeException(e);
}finally {
connection.close();
preparedStatement.close();
in.close();
}
%>
<p style="text-align:center;color: black; font-family: 宋体; font-size: 20px">
<br> <input type="button" value="好吃不嫌多" onclick="location.href='start.jsp'" />
<input type="button" value="匿了匿了" onclick="location.href='mune.jsp'" />
<br>
</table>
</body>
</html>
start
success.jsp 操作成功则跳转到此页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>失败咯</title>
</head>
<body>
<h1 align="center">
成功咯<br>
<input type="button" value="返回主界面" onclick="location.href='mune.jsp'" />
</h1>
</body>
</html>
success
defeat.jsp 操作失败跳转到此页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>失败咯</title>
</head>
<body>
<h1 align="center">
失败咯<br>
<input type="button" value="返回主界面" onclick="location.href='mune.jsp'" />
</h1>
</body>
</html>
defeat
本来应该昨天发的，但是没有解决模糊查询的小问题（气抖冷，原因是没有限制传入数据的编码格式，导致中文变乱码查询失败）和再次发烧实在没心思找错，就当周末编程总结吧
标签：25,26,request,words,2023,close,import,null,public From： https://www.cnblogs.com/xxaxf/p/17156512.html