首先是设计思路，对于数据库的增删改查，我们借助Ecilipse来进行前端和后端的编写。Ecilipse是可以进行java web项目的操作的。
前端，我们选择用使用jsp，所谓的jsp就是可以嵌入其他语言的html,各种标识语言和html语法一致，但为了在本界面检测各种信息的正确性，需要嵌入java的语句进行判断。
对于数据库的增删改查，我们使用sql语句，并且导入了相应的mysql的jar包，方便我们用java对数据库进行操作。
整体来说，我们编写使用了MVC模式(model-view-controler)来实现各种设计。具体的解释不再赘述，下面是一些效果图：
(主界面)
（添加信息界面，即增删改查中的增）
（修改界面，即增删改查中的改）
（删除界面，即增删改查中的删）
（查询界面，即查。该界面设计了一个综合查询功能，即可以进行多条件的综合查询）
下面是各个界面和后端的代码：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>石家庄铁道大学青年志愿者服务网</title>
</head>
<body>
<div align="center" style="color:#6C3365;position:relative;top:85px;font-size:25px">
<p>青年志愿服务网</p>
</div>
<div align="center" style="position:relative;top:100px">
<button onclick="window.location.href=‘add.jsp‘">志愿者信息登记</button>
</div>
<div align="center" style="position:relative;top:110px">
<button onclick="window.location.href=‘revise.jsp‘">修改志愿者信息</button>
</div>
<div align="center" style="position:relative;top:120px;">
<button onclick="window.location.href=‘delete.jsp‘">删除志愿者信息</button>
</div>
<div align="center" style="position:relative;top:130px">
<button onclick="window.location.href=‘search.jsp‘">查询志愿者信息</button>
</div>
<div align="center" style="position:relative;top:140px">
<button onclick="window.location.href=‘Servlet?method=show‘">志愿者信息浏览</button>
</div>
<div align="center" style="color:#6C3365;position:relative;top:150px">
<p>Designed By wushen</p>
</div>
</body>
</html>
主界面代码
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>志愿者信息录取界面</title> <STYLE TYPE="text/css"> <!-- table{margin:auto} --> </STYLE> <script type="text/javascript"> /*表单校验*/ function check() { f=0; var name = document.getElementById("name").value; if(name.length!=0){ f ; } else {alert("请输入姓名!");return false;} var sex=document.getElementById("sex").value; if(sex.length!=0){ f ; } else {alert("请输入性别!");return false;} var nation=document.getElementById("nation").value; if(nation.length!=0){ f ; } else {alert("请输入民族!");return false;} var time =document.getElementById("time").value; if(time.length!=0){ f ; } else {alert("请输入注册时间!");return false;} var political =document.getElemById("political").value; if(political.length!=0||political.value!="--请选择--"){ f ; } else {alert("请选择政治面貌!");return false;} if(f>=6){ alert("添加志愿者信息成功!"); return true; } else{ alert("添加失败,请检查信息是否正确!"); return false; } } </script> </head> <body> <h1>添加志愿者信息界面</h1> <p align="right"><a href="main.jsp">返回主界面</a></p><hr> <form action="Servlet?method=add" method="post" onsubmit="return check()"><br/><br/><br/><br/><br/><br/><br/> <table frame= "box"> <tr> <td>姓名</td> <td><input type="text" id="name" name="name" value="" ></td> </tr> <tr> <td>性别</td> <td> <input type="radio" name="sex" value="男">男 <input type="radio" name="sex" value="女">女 </td> </tr> <tr> <td>民族</td> <td><input type="text" id="nation" name="nation" value=""></td> </tr> <tr> <td>注册时间</td> <td><input type="text" id="time" name="time" value=""></td> </tr> <tr> <td>年龄</td> <td><input type="text" id="year" name="year" value=""></td> </tr> <tr> <td>政治面貌:</td> <td> <select id="political" name="political" > <option>--请选择--</option> <option value="群众">群众</option> <option value="共青团员">共青团员</option> <option value="中*员">中*员</option> </select> </td> </tr> <tr> <td>服务类别(最多四项)</td> <td> <div> <input type="checkbox" name="type" value="扶危济贫">扶危济贫 <input type="checkbox" name="type" value="敬老助残">敬老助残 <input type="checkbox" name="type" value="社区服务">社区服务 <input type="checkbox" name="type" value="秩序维护">秩序维护 <input type="checkbox" name="type" value="文体服务">文体服务 </div> <div> <input type="checkbox" name="type" value="环境保护">环境保护 <input type="checkbox" name="type" value="治安防范">治安防范 <input type="checkbox" name="type" value="医疗救治">医疗救治 <input type="checkbox" name="type" value="法律援助">法律援助 <input type="checkbox" name="type" value="大型活动">大型活动 </div> <div> <input type="checkbox" name="type" value="心理疏导">心理疏导 <input type="checkbox" name="type" value="精神抚慰">精神抚慰 <input type="checkbox" name="type" value="支教支医">支教支医 <input type="checkbox" name="type" value="科学普及">科学普及 <input type="checkbox" name="type" value="应急救援">应急救援 </div> <div> <input type="checkbox" name="type" value="便民服务">便民服务 <input type="checkbox" name="type" value="民事调解">民事调解 <input type="checkbox" name="type" value="文明引导">文明引导 <input type="checkbox" name="type" value="安全生产">安全生产 <input type="checkbox" name="type" value="禁毒宣传">禁毒宣传 </div> </td> </tr> <tr> <td><td> <td> <button type="submit" >提 交</button></td> </tr> <tr> <td colspan="2"> <font color="red">${message}</font> </td> </tr> </table> </form> </body> </html>添加信息界面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>志愿者信息修改界面</title> </head> <body> <h1 align="left">按姓名查询并修改界面</h1><p align="right"><a href="main.jsp">返回主界面</a></p><hr> <form action="Servlet?method=ch_u" method="post" > <table align="center" bgcolor="#FFFFFF"> <tr> <td> 姓名 </td> <td > <input type="text" name="name" id="name"> </td> </tr> <tr> <td colspan="2"> <input class="btn btn-default" type="submit" value="查询"> </td> </tr> <tr> <td colspan="2"> <font color="green">${message}</font> </td> </tr> </table> </form> <c:if test="${message eq ‘查询成功‘}"> <form action="Servlet?method=revise" method="post" onsubmit="return check()"><br/><br/><br/><br/><br/><br/><br/> <table frame= "box"> <tr> <td>姓名</td> <td><input type="text" id="name" name="name" value="${U.name}" ></td> </tr> <tr> <td>性别</td> <td> <input type="radio" name="sex" value="男">男 <input type="radio" name="sex" value="女">女 </td> </tr> <tr> <td>民族</td> <td><input type="text" id="nation" name="nation" value="${U.nation}"></td> </tr> <tr> <td>注册时间</td> <td><input type="text" id="time" name="time" value="${U.time}"></td> </tr> <tr> <td>年龄</td> <td><input type="text" id="year" name="year" value="${U.year}"></td> </tr> <tr> <td>政治面貌:</td> <td> <select id="political" name="political" > <option value="${U.political}"></option> <option value="群众">群众</option> <option value="共青团员">共青团员</option> <option value="中*员">中*员</option> </select> </td> </tr> <tr> <td>服务类别(最多四项)</td> <td>已选:${U.type}</td><br> <td> <input type="checkbox" name="type" value="扶危济贫">扶危济贫 <input type="checkbox" name="type" value="敬老助残">敬老助残 <input type="checkbox" name="type" value="社区服务">社区服务 <input type="checkbox" name="type" value="秩序维护">秩序维护 <input type="checkbox" name="type" value="文体服务">文体服务 <input type="checkbox" name="type" value="环境保护">环境保护 <input type="checkbox" name="type" value="治安防范">治安防范 <input type="checkbox" name="type" value="医疗救治">医疗救治 <input type="checkbox" name="type" value="法律援助">法律援助 <input type="checkbox" name="type" value="大型活动">大型活动 <input type="checkbox" name="type" value="心理疏导">心理疏导 <input type="checkbox" name="type" value="精神抚慰">精神抚慰 <input type="checkbox" name="type" value="支教支医">支教支医 <input type="checkbox" name="type" value="科学普及">科学普及 <input type="checkbox" name="type" value="应急救援">应急救援 <input type="checkbox" name="type" value="便民服务">便民服务 <input type="checkbox" name="type" value="民事调解">民事调解 <input type="checkbox" name="type" value="文明引导">文明引导 <input type="checkbox" name="type" value="安全生产">安全生产 <input type="checkbox" name="type" value="禁毒宣传">禁毒宣传 </td> </tr> <tr> <td><td> <td> <button type="submit" >修 改</button></td> </tr> <tr> <td colspan="2"> <font color="green">${message}</font> </td> </tr> </table> </form> </c:if> </body> </html>修改信息界面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>志愿者信息删除界面</title> </head> <body> <h1 align="left">按姓名查询并删除界面</h1><p align="right"><a href="main.jsp">返回主界面</a></p><hr> <form action="Servlet?method=d_u" method="post" > <table align="center" bgcolor="#FFFFFF"> <tr> <td> 姓名 </td> <td > <input type="text" name="name" id="name"> </td> </tr> <tr> <td colspan="2"> <input class="btn btn-default" type="submit" value="查询"> </td> </tr> <tr> <td colspan="2"> <font color="red">${message}</font> </td> </tr> </table> </form> <c:if test="${message eq ‘查询成功‘}"> <form action="Servlet?method=delete" method="post" onSubmit="return confirm(‘真的要删除吗?‘);"><br/><br/><br/><br/><br/><br/><br/> <table frame= "box"> <tr> <td>姓名</td> <td><input type="text" id="name" name="name" value="${U.name}" ></td> </tr> <tr> <td>性别</td> <td> <input type="radio" name="sex" value="男">男 <input type="radio" name="sex" value="女">女 </td> </tr> <tr> <td>民族</td> <td><input type="text" id="nation" name="nation" value="${U.nation}"></td> </tr> <tr> <td>注册时间</td> <td><input type="text" id="time" name="time" value="${U.time}"></td> </tr> <tr> <td>年龄</td> <td><input type="text" id="year" name="year" value="${U.year}"></td> </tr> <tr> <td>政治面貌:</td> <td> <select id="political" name="political" > <option value="${U.political}"></option> <option value="群众">群众</option> <option value="共青团员">共青团员</option> <option value="中*员">中*员</option> </select> </td> </tr> <tr> <td>服务类别(最多四项)</td> <td>已选:${U.type}</td><br> <td> <input type="checkbox" name="type" value="扶危济贫">扶危济贫 <input type="checkbox" name="type" value="敬老助残">敬老助残 <input type="checkbox" name="type" value="社区服务">社区服务 <input type="checkbox" name="type" value="秩序维护">秩序维护 <input type="checkbox" name="type" value="文体服务">文体服务 <input type="checkbox" name="type" value="环境保护">环境保护 <input type="checkbox" name="type" value="治安防范">治安防范 <input type="checkbox" name="type" value="医疗救治">医疗救治 <input type="checkbox" name="type" value="法律援助">法律援助 <input type="checkbox" name="type" value="大型活动">大型活动 <input type="checkbox" name="type" value="心理疏导">心理疏导 <input type="checkbox" name="type" value="精神抚慰">精神抚慰 <input type="checkbox" name="type" value="支教支医">支教支医 <input type="checkbox" name="type" value="科学普及">科学普及 <input type="checkbox" name="type" value="应急救援">应急救援 <input type="checkbox" name="type" value="便民服务">便民服务 <input type="checkbox" name="type" value="民事调解">民事调解 <input type="checkbox" name="type" value="文明引导">文明引导 <input type="checkbox" name="type" value="安全生产">安全生产 <input type="checkbox" name="type" value="禁毒宣传">禁毒宣传 </td> </tr> <tr> <td><td> <td> <button type="submit" >删 除</button></td> </tr> <tr> <td colspan="2"> <font color="blue">${message}</font> </td> </tr> </table> </form> </c:if> </body> </html>删除信息界面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>志愿者信息查找界面</title> </head> <body> <h1 align="left">查询界面</h1><p align="right"><a href="main.jsp">返回主界面</a></p><hr> <form action="Servlet?method=q_u" method="post" > <table align="center" bgcolor="#FFFFFF"> <tr> <td> 姓名 </td> <td> <input type="text" name="name" id="name"> </td> <td> <select id="type1" name="type1" > <option>--请选择--</option> <option value="0">精确查询</option> <option value="1">模糊查询</option> </select> </td> </tr> <tr> <td > 性别 </td> <td> <input type="text" name="sex" id="sex" > </td> </tr> <tr> <td> 民族 </td> <td> <input type="text" name="nation" id="nation"> </td> </tr> <tr> <td>政治面貌</td> <td><input type="text" name="political" id="political"> </td> </tr> <tr> <td>服务类别</td> <td><input type="text" name="type" id="type"></td> </tr> <tr> <td>注册时间</td> <td><input type="text" name="time" id="time"></td> </tr> <tr> <td colspan="2"> <input class="btn btn-default" type="submit" value="查询"> </td> </tr> <tr> <td colspan="2"> <font color="red">${message}</font> </td> </tr> </table> </form> <c:if test="${message eq ‘查询成功‘}"> <table align="center" bgcolor="#FFFFFF" class="table table-bordered" > <tr> <td> 姓名 </td> <td> ${U.name} </td> </tr> <tr> <td> 性别 </td> <td> ${U.sex}<br> </td> </tr> <tr> <td> 民族 </td> <td> ${U.nation} </td> <tr> <td> 注册时间 </td> <td> ${U.time} </td> <tr> <td> 年龄 </td> <td> ${U.year} </td> </tr> <tr> <td> 政治面貌 </td> <td> ${U.political} </td> </tr> <tr> <td> 服务类别 </td> <td> ${U.type} </td> </tr> </table> </c:if> </body> </html>查询信息界面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>志愿者信息浏览界面</title> </head> <body> <h2 align=center>所有志愿者信息</h2><p align="right"><a href="main.jsp">返回主界面</a></p><hr> <form action="Servlet?method=showinfo" method="post"> <table align=center> <tr> <th class="w1">姓名</th> <th class="w1">性别</th> <th class="w1">民族</th> <th class="w1">政治面貌</th> </tr> <c:forEach items="${userlist}" var="item"> <tr> <td class="w1"><a href="Servlet?method=showinfo&name=${item.name}">${item.name}</a></td> <td class="w1">${item.sex}</td> <td class="w1">${item.nation}</td> <td class="w1">${item.political}</td> </tr> </c:forEach> </table> </form> </body> </html>浏览志愿者信息简洁界面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>志愿者详细信息浏览界面</title>
</head>
<body>
<h2 align=center>志愿者信息</h2><p align="right"><a href="main.jsp">返回主界面</a></p><hr>
<table align=center>
<tr>
<th class="w1">姓名</th>
<th class="w1">性别</th>
<th class="w1">民族</th>
<th class="w1">政治面貌</th>
<th class="w1">注册时间</th>
<th class="w1">年龄</th>
<th class="w1">服务类别</th>
</tr>
<tr>
<td class="w1">${U.name}</td>
<td class="w1">${U.sex}</td>
<td class="w1">${U.nation}</td>
<td class="w1">${U.political}</td>
<td class="w1">${U.time}</td>
<td class="w1">${U.year}</td>
<td class="w1">${U.type}</td>
</tr>
</table>
</body>
</html>
详细信息界面
Sevlet层：
package servlet; import java.io.IOException; import user.User; import java.io.IOException; import java.sql.Connection; import java.sql.PreparedStatement; import java.util.ArrayList; import java.util.List; import dao.Dao; 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 Servlet extends HttpServlet{ private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public Servlet() { super(); } Dao dao = new Dao(); private void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { User user = new User(req.getParameter("name"),req.getParameter("sex"),req.getParameter("nation"),req.getParameter("time"),req.getParameter("year"),req.getParameter("political"),req.getParameter("type")); if(dao.add(user.getname(),user.getsex(),user.getnation(),user.gettime(),user.getyear(),user.getpolitical(),user.gettype() )) { req.setAttribute("message", "添加志愿者信息成功"); req.getRequestDispatcher("show.jsp").forward(req,resp); }else { req.setAttribute("message", "添加志愿者信息失败"); req.getRequestDispatcher("add.jsp").forward(req,resp); } } private void show(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{ req.setCharacterEncoding("utf-8"); List<User>userlist = dao.show(); req.setAttribute("userlist", userlist); req.getRequestDispatcher("show.jsp").forward(req,resp); } private void showinfo(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{ req.setCharacterEncoding("utf-8"); User user = dao.Q_U(req.getParameter("name"),req.getParameter("sex"),req.getParameter("nation"),req.getParameter("time"),req.getParameter("political"),req.getParameter("type")); System.out.println(req.getParameter("name")); req.setAttribute("U",user); req.getRequestDispatcher("showinfo.jsp").forward(req,resp); } public void delete(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{ req.setCharacterEncoding("UTF-8"); String name=req.getParameter("name"); if(dao.delete(name)) {//进行数据库的删除操作 req.setAttribute("message", "删除成功"); }else { req.setAttribute("message", "删除失败"); } req.getRequestDispatcher("delete.jsp").forward(req, resp); } public void d_u(HttpServletRequest req, HttpServletResponse resp)throws IOException, ServletException { User user =dao.Q_U(req.getParameter("name"),req.getParameter("sex"),req.getParameter("nation"),req.getParameter("time"),req.getParameter("political"),req.getParameter("type")); if(user!=null) { req.setAttribute("message", "查询成功"); req.setAttribute("U", user); req.getRequestDispatcher("delete.jsp").forward(req,resp); }else { req.setAttribute("message", "该志愿者信息不存在"); req.setAttribute("U", user); req.getRequestDispatcher("delete.jsp").forward(req,resp); } } public void ch_u(HttpServletRequest req, HttpServletResponse resp)throws IOException, ServletException { User user =dao.Q_U(req.getParameter("name"),req.getParameter("sex"),req.getParameter("nation"),req.getParameter("time"),req.getParameter("political"),req.getParameter("type")); if(user!=null) { req.setAttribute("message", "查询成功"); req.setAttribute("U", user); req.getRequestDispatcher("revise.jsp").forward(req,resp); }else { req.setAttribute("message", "该志愿者信息不存在"); req.setAttribute("U", user); req.getRequestDispatcher("revise.jsp").forward(req,resp); } } public void revise(HttpServletRequest req,HttpServletResponse resp)throws IOException,ServletException{ req.setCharacterEncoding("utf-8"); String name = req.getParameter("name"); String sex = req.getParameter("sex"); String nation=req.getParameter("nation"); String time=req.getParameter("time"); String year=req.getParameter("year"); String political = req.getParameter("political"); String type =req.getParameter("type"); User user=new User(name,sex,nation,time,year,political,type); dao.revise(user.getname(),user.getsex(),user.getnation(),user.gettime(),user.getyear(),user.getpolitical(),user.gettype());//进行数据库的修改操作 req.setAttribute("message", "修改成功"); req.getRequestDispatcher("revise.jsp").forward(req,resp); } public void q_u(HttpServletRequest req, HttpServletResponse resp)throws IOException, ServletException { String type=req.getParameter("type1"); if(type.equals("0")) { User user =dao.Q_U(req.getParameter("name"),req.getParameter("sex"),req.getParameter("nation"),req.getParameter("time"),req.getParameter("political"),req.getParameter("type")); if(user!=null) { req.setAttribute("message", "查询成功"); req.setAttribute("U", user); req.getRequestDispatcher("search.jsp").forward(req,resp); }else { req.setAttribute("message", "该志愿者信息不存在"); req.setAttribute("U", user); req.getRequestDispatcher("search.jsp").forward(req,resp); } } else if(type.equals("1")) { } if(type!="1"&&type!="0"){ req.setAttribute("message","请选择查询方式"); req.getRequestDispatcher("search.jsp").forward(req,resp); } } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); String method = request.getParameter("method"); System.out.println(method); if("add".equals(method)) { add(request,response); } else if("show".equals(method)) { show(request,response); } else if("delete".equals(method)) { delete(request,response); } else if("d_u".equals(method)) { d_u(request,response); } else if("revise".equals(method)) { revise(request,response); } else if("q_u".equals(method)) { q_u(request,response); } else if("ch_u".equals(method)) { ch_u(request,response); } else if("showinfo".equals(method)) { showinfo(request,response); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }Servlet
封装用户属性的java bean
package user; public class User { private String name; private String sex; private String nation; private String time; private String year; private String political; private String type; public User(String name,String sex,String nation,String time,String year,String political,String type){ this.name=name; this.sex=sex; this.nation=nation; this.time=time; this.year=year; this.political=political; this.type=type; } public String getname() { return name; } public String getsex() { return sex; } public String getnation() { return nation; } public String gettime() { return time; } public String getyear() { return year; } public String getpolitical() { return political; } public String gettype() { return type; } }User
Dao层
package dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import database.DB; import user.User; public class Dao { public static boolean add(String name,String sex,String nation,String time,String year,String political,String type) { Connection conn = null; PreparedStatement pstmt = null; boolean pd = false; System.out.println("add run!"); try { //获取连接 conn = DB.getConn(); //编写语句 String sql = "insert into volunteer values(?,?,?,?,?,?,?)"; //预编译 pstmt = conn.prepareStatement(sql); //设置数据 pstmt.setString(1, name); pstmt.setString(2, sex); pstmt.setString(3, nation); pstmt.setString(4,time); pstmt.setString(5,year); pstmt.setString(6,political); pstmt.setString(7,type); //执行 int res = pstmt.executeUpdate(); //判断 if(res>0) { pd=true; }else { pd=false; } } catch (Exception e) { e.printStackTrace(); }finally { DB.close(pstmt,conn); } return pd; } public boolean delete(String name) { boolean pd=false; Connection connection = DB.getConn(); String sql = "delete from volunteer where name = ?"; PreparedStatement preparedStatement = null; System.out.println("detelte run!"); try { preparedStatement = connection.prepareStatement(sql); preparedStatement.setString(1, name); int res=preparedStatement.executeUpdate(); if(res>0) { pd=true; } else { pd=false; } } catch (Exception e) { e.printStackTrace(); }finally { DB.close(preparedStatement,connection); } return pd; } public void revise(String name,String sex,String nation,String time,String year,String political,String type) { Connection connection = DB.getConn(); //准备sql语句 String sql = "update volunteer set name = ? , sex=?,nation = ?,time=?,year=?,political=?,type=?"; //创建语句传输对象 PreparedStatement preparedStatement = null; try { preparedStatement = connection.prepareStatement(sql); preparedStatement.setString(1, name); preparedStatement.setString(2, sex); preparedStatement.setString(3, nation); preparedStatement.setString(4,time); preparedStatement.setString(5,year); preparedStatement.setString(6,political); preparedStatement.setString(7,type); preparedStatement.executeUpdate(); } catch (Exception e) { e.printStackTrace(); }finally { DB.close(preparedStatement,connection); } } public List<User> show() { List<User> userlist =new ArrayList<>(); Connection conn = DB.getConn(); ResultSet rs= null; String sql="select * from volunteer"; User user =null; Statement stmt=null; try { stmt=conn.createStatement(); rs=stmt.executeQuery(sql); while(rs.next()){ String name=rs.getString("name"); String sex=rs.getString("sex"); String nation=rs.getString("nation"); String time=rs.getString("time"); String year=rs.getString("year"); String political =rs.getString("political"); String type=rs.getString("type"); user = new User(name,sex,nation,time,year,political,type); userlist.add(user); } }catch(Exception e) { e.printStackTrace(); } finally { DB.close(rs,stmt,conn); } return userlist; } public User Q_U(String name,String sex1,String nation1,String time1,String political1,String type1){ String sql="select * from volunteer where 1 = 1"; Connection conn=null; PreparedStatement pstmt = null; ResultSet rs= null; if(name!=null) { sql ="and name= ? "; } if(sex1!=null) { sql ="and sex= ? "; } System.out.println(sql); try { conn=DB.getConn(); pstmt=(PreparedStatement) conn.prepareStatement(sql); pstmt.setString(1,name); pstmt.setString(2,sex1); rs =(ResultSet)pstmt.executeQuery(); while(rs.next()) { String name1=rs.getString("name"); String sex=rs.getString("sex"); String nation=rs.getString("nation"); String time =rs.getString("time"); String year=rs.getString("year"); String political =rs.getString("political"); String type=rs.getString("type"); User user = new User(name1,sex,nation,time,year,political,type); return user; } }catch(Exception e) { e.printStackTrace(); }finally { DB.close(rs,pstmt,conn); } return null; } }
连接数据库的java bean
package database; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DB { public static String db_url = "jdbc:mysql://localhost:3306/student?useSSL=false&serverTimezone=UTC&characterEncoding=UTF-8&useOldAliasMetadataBehavior=true"; public static String db_user = "root"; public static String db_pass = "abc456"; public static Connection getConn () { Connection conn = null; try { Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动 conn = DriverManager.getConnection(db_url, db_user, db_pass); } catch (Exception e) { e.printStackTrace(); } return conn; } /** * 关闭连接 * @param state * @param conn */ 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(); } } } public static void main(String[] args) throws SQLException { Connection conn = getConn(); PreparedStatement pstmt = null; ResultSet rs = null; String sql ="select * from USER"; pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if(rs.next()){ System.out.println("空"); }else{ System.out.println("不空"); } } }Database