public boolean delete(int a ) {
boolean flag=false;//删除 搜索并删除表 no1 中 A 列为 a 的那一行
Connection conn =link.Link.getConnection();
Statement st=null;
try {
st=conn.createStatement();
st.executeUpdate("delete from no1 where A='"+a+"'");
flag=true;
} catch (SQLException e) {
e.printStackTrace();
}
finally{
link.Link.close(st, conn);
}
return flag;
}
public boolean update(Bean bean) {
boolean flag=false;//更改 更改表 no1 中 A 列为 bean.getA() 的那一行
Connection conn=link.Link.getConnection();
Statement st=null;
try {
st=conn.createStatement();
st.executeUpdate("update no1 set A='"+bean.geta()+"',B='"+bean.getb()+"',C='"+bean.getc()+"'where A='"+bean.geta()+"'");
flag=true;
} catch (SQLException e) {
e.printStackTrace();
}
return flag;
}
public List<Bean> list(){
Connection conn=link.Link.getConnection();
Statement st=null;//浏览 表 no1 中 A 列
List<Bean> list=new ArrayList<>();
ResultSet rs=null;
Bean bean=null;
try {
st=conn.createStatement();
rs=st.executeQuery("select * from no1 order by A");
while(rs.next()) {
int A=rs.getInt("A");
String B = rs.getString("B");
String C = rs.getString("C");
bean=new Bean(A,B,C);
list.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
}
finally {
link.Link.close(rs, st, conn);
}
return list;
}
public List<Bean> searchByName(String str) throws SQLException{
Connection conn=link.Link.getConnection();
Statement st=null;//查询 表 no1 中 B 或 C 列中存在 str 的
PreparedStatement pt = conn.prepareStatement("select * from no1 where(B like '%"+str+"%' or C like '%"+str+"%')");
List<Bean> search=new ArrayList<>();
ResultSet rs=null;
Bean bean=null;
try {
rs=pt.executeQuery();
while(rs.next()) {
int A=rs.getInt("A");
String B = rs.getString("B");
String C = rs.getString("C");
bean=new Bean(A,B,C);
search.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
}
finally {
link.Link.close(rs, st, conn);
}
return search;
}
}
Link
package link;
import java.sql.*;
public class Link {
private static String url = "jdbc:mysql://localhost:3306/end?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8";
private static String user = "root";
private static String password = "123456";
public static Connection getConnection() {
Connection con=null;
try {
con=DriverManager.getConnection(url, user, password);
System.out.println("连接成功");
} catch (Exception e) {
e.printStackTrace();
}
return con;
}
public static void close(Connection con) {
if(con!=null)
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(Statement state, Connection conn) {
if(state!=null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close(ResultSet rs, Statement state, Connection conn) {
if(rs!=null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(state!=null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
Servlet.java
package servlet;
import java.io.*;
import java.util.List;
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 bean.Bean;
import dao.Dao;
@WebServlet("/servlet")
public class Servlet extends HttpServlet {
Dao Dao=new dao.Dao();
private static final long serialVersionUID = 1L;
public Servlet() {
super();
}
private void insert(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
request.setCharacterEncoding("utf-8");
int A = Integer.parseInt(request.getParameter("A"));
String B = request.getParameter("B");
String C = request.getParameter("C");
Bean bean=new Bean(A,B,C);
if(Dao.insert(bean)) {
request.setAttribute("message", "添加成功");
request.getRequestDispatcher("index.jsp").forward(request, response);
}
}
private void delete(HttpServletRequest request, HttpServletResponse response) throws Exception, IOException {
request.setCharacterEncoding("UTF-8");
int A=Integer.parseInt(request.getParameter("A"));
Dao.delete(A);
request.setAttribute("message", "删除成功");
request.getRequestDispatcher("servlet?method=list").forward(request, response);
}
private void list(HttpServletRequest request, HttpServletResponse response) throws Exception, IOException {
request.setCharacterEncoding("UTF-8");
List<Bean> list = Dao.list();
request.setAttribute("list", list);
request.getRequestDispatcher("list.jsp").forward(request, response);
}
private void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
int A = Integer.parseInt(request.getParameter("A"));
String B = request.getParameter("B");
String C = request.getParameter("C");
Bean bean=new Bean(A,B,C);
Dao.update(bean);
request.setAttribute("message", "修改成功");
request.getRequestDispatcher("servlet?method=list").forward(request, response);
}
private void search(HttpServletRequest request, HttpServletResponse response) throws Exception, IOException {
request.setCharacterEncoding("UTF-8");
request.setAttribute("search", "查询成功");
request.getRequestDispatcher("list.jsp").forward(request, response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
String method=request.getParameter("method");
if("insert".equals(method)) {
insert(request,response);
}else if("delete".equals(method)) {
try {
delete(request,response);
}catch (Exception e) {
e.printStackTrace();
}
}else if("update".equals(method)) {
update(request,response);
}else if("list".equals(method)) {
try {
list(request,response);
}catch (Exception e) {
e.printStackTrace();
}
}else if("search".equals(method)) {
try {
search(request,response);
} catch (Exception e) {
e.printStackTrace();
}
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>这里是标题</title>
</head>
<body>
<%
Object message = request.getAttribute("message");
if (message != null && !"".equals(message)) {
%>
<script type="text/javascript"> alert("<%=request.getAttribute("message")%>"); </script>
<%}%>
<div align="center">
<h1>表名</h1>
<a href="A.jsp">跳转A</a>
<form action="servlet?method=insert" method="post">
<table id="addTable" class="table table-bordered ">
<tr>
<td class="col-sm-2">输入框A</td>
<td class="col-sm-4"><input type="text" class="form-control" name="输入框A" id="输入框A" ></td>
<tr>
<td class="col-sm-2">输入框B</td>
<td><input type="text" class="form-control" name="输入框B" id="输入框B" placeholder="输入框B"></td>
<tr>
<td class="col-sm-2">选择框</td>
<td class="col-sm-4">
<input type="radio" name="选择框" id="选择框" value="内容A">内容A
<input type="radio" name="选择框" id="选择框" value="内容B">内容B
</td> <tr> <td></td> <td>
<input type="radio" name="选择框" id="选择框" value="内容C">内容C
</td>
<tr>
<td>下拉框</td>
<td colspan="3">
<select class="form-control" id="下拉框" name="下拉框">
<option value="下拉框A">下拉框A</option>
<option value="下拉框B">下拉框B</option>
<option value="下拉框C">下拉框C</option>
</select>
</td>
<tr>
</table>
<input type="submit" value="确认" onclick= "return check()" />
</form>
</div>
</body>
<script type="text/javascript">
function check()
{
if(document.getElementById('输入框A').value=='') {
alert('输入框A不能为空！');
document.getElementById('输入框A').focus();
return false;
}else if(document.getElementById('输入框A').value%1!=0){
alert('输入框A不是整数！');
document.getElementById('输入框A').focus();
return false;
}
if(document.getElementById('输入框B').value=='') {
alert('输入框B不能为空！');
document.getElementById('输入框B').focus();
return false;
}else if(document.getElementById('输入框B').value.length!=18) {
alert('输入框B位数错误！');
document.getElementById('输入框B').focus();
return false;
}
}
</script>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>这里是标题</title>
</head>
<body>
<%
Object message =request.getAttribute("message");
if(message!=null&&!"".equals(message)){
%>
<script type="text/javascript">alert("<%=request.getAttribute("message")%>");</script>
<%}%>
<p style="text-align:center;color:black;font-family:宋体,serif; font-size:30px">
这里是介绍
</p>
<p style="text-align:center">
<br>
<input type="button" value="跳转A" onclick="location.href='A.jsp'" />
<br><br>
<input type="button" value="跳转B" onclick="location.href='B.jsp'" />
<br><br>
<input type="button" value="返回上一页" onclick="javascript:history.back(-1)" />
</p>
</body>
</html>