MyEclipse------制作通讯录

public class addinfo extends HttpServlet {
    private String url="jdbc:mysql://localhost:3306/student?useSSL=true";
    private String useName="root";
    private String password="2277092";
    private Connection conn=null;
    private PreparedStatement pstmt=null;
    private Statement stmt=null;
    private ResultSet rs=null;
    private String sql=null;
    
    private static final long serialVersionUID = 1L;

    public addinfo() {
        super();
    }

    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request,response);
    }
    
    //建立数据库的连接
    public void setConn(){
        try{
            Class.forName("com.mysql.jdbc.Driver");
            conn=DriverManager.getConnection(url,useName,password);
        }
        catch(Exception e){
            e.printStackTrace();
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        setConn();
        
        request.setCharacterEncoding("gb2312");
        response.setContentType("text/html;charset=gb2312");
        
        //int no=Integer.parseInt(request.getParameter("no"));
        String no=request.getParameter("no");
        String name=request.getParameter("name");
        String phone=request.getParameter("phone");
        String sex=request.getParameter("sex");
        String address=request.getParameter("address");
        //System.out.print(name+phone+sex+address);
        if(no.equals("")||name.equals("")||phone.equals("")||sex.equals("")||address.equals("")){
            request.setAttribute("tips", "信息不能为空");
            RequestDispatcher dispatcher=request.getRequestDispatcher("/splitpage2/add.jsp");
            dispatcher.forward(request, response);
        }
        
        try {
            //判断学号是否已经存在
            stmt=conn.createStatement();
            rs=stmt.executeQuery("select * from info;");
            while(rs.next()){
                int num=rs.getInt(1);
                if(no.equals(num)){
                    //System.out.print("该学号已经存在");
                    request.setAttribute("tips", "该学号已经存在");
                    RequestDispatcher dispatcher=request.getRequestDispatcher("/splitpage2/add.jsp");
                    dispatcher.forward(request, response);
                }    
            }
            
            sql="insert into info values(?,?,?,?,?)";
            pstmt=conn.prepareStatement(sql);
            pstmt.setString(1, no);
            pstmt.setString(2, name);
            pstmt.setString(3, phone);
            pstmt.setString(4, sex);
            pstmt.setString(5, address);
            pstmt.executeUpdate();
    
            rs.close();
            stmt.close();
            pstmt.close();
            if(conn!=null){
                conn.close();
                //System.out.print("数据库关闭成功");
            }
            
            //跳转回首页
            RequestDispatcher dispatcher=request.getRequestDispatcher("/splitpage2/list.jsp");
            dispatcher.forward(request, response);
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.out.print("出错le");
        }
    }

    public void init() throws ServletException {
        // Put your code here
    }

}

public class deleteinfo extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private String url="jdbc:mysql://localhost:3306/student?useSSL=true";
    private String useName="root";
    private String password="2277092";
    private String sql="";
    private Connection conn=null;
    private Statement stmt=null,stmt2=null;
    private ResultSet rs=null;

    public deleteinfo() {
        super();
    }

    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doPost(request,response);
    }

    //连接数据库
    private void setConn(){
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn=DriverManager.getConnection(url,useName,password);
            //System.out.print("数据库连接成功，加载驱动类成功");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        setConn();
        
        request.setCharacterEncoding("gb2312");
        response.setContentType("text/html;charset=gb2312");
        
        String no=request.getParameter("no");
        
        sql="select * from info;";
        try {
            stmt=conn.createStatement();
            stmt2=conn.createStatement();
            rs=stmt.executeQuery(sql); //执行完后rs会关闭，所以要用stmt2，即使也能运行，但会抛出异常
            while(rs.next()){
                String num=rs.getString(1);
                if(no.equals(num)){
                    stmt2.execute("delete from info where no="+no+";");
                    RequestDispatcher dispatcher=request.getRequestDispatcher("/splitpage2/list.jsp");
                    dispatcher.forward(request, response);
                }
            }
            rs.close();
            stmt.close();
            stmt2.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        try{
            conn.close();
            //System.out.print("成功关闭数据库");
        }
        catch(SQLException e){
            e.printStackTrace();
        }
        
    }

    public void init() throws ServletException {
        // Put your code here
    }

}

public class downfile extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public downfile() {
        super();
    }

    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

    }
    
    

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        super.service(request, response);
        String path="E:\\Tomcat\\webapps\\MyWeb\\myfile\\"; //文件读取路径
        response.reset(); //清除缓冲区中的任何数据存在的状态码和标题
        try {
            String str = request.getParameter("name");
            //第一个参数为要解码的字节字符,第二个参数为解码方法
            //getBytes()里面的参数为str原来的编码方式
            //str = new String(str.getBytes("UTF-8"), "UTF-8");
            
            //path = path.substring(0, path.lastIndexOf("\\"));
            //path = path + "\\myfile\\";

            //第一个参数为路径，第二个参数文件名
            File fileLoad = new File(path, str);
            response.reset();

            //输出流
            OutputStream o = response.getOutputStream();
            BufferedOutputStream bos = new BufferedOutputStream(o); //增强写入文件的能力
            
            //输出文件用的字节数组，每次发送500个字节到输出流
            //在内存开辟内存空间，最大一次读取500字节
            byte b[] = new byte[500];

            //客户端使用保存文件的对话框
            response.setHeader(
                    "Content-disposition", //指定文件的类型是文件的扩展名
                    "attachment;filename=" //指定文件的名字
                            + new String(str.getBytes("UTF-8"), "UTF-8"));
            //通知客户文件的MIMIE类型
            response.setContentType("application/x-tar");
            long fileLength = fileLoad.length();
            String length = String.valueOf(fileLength);
            response.setHeader("Content_length", length);
            
            //文件字节流读取文件
            FileInputStream in = new FileInputStream(fileLoad); 
            int n = 0;
            while ((n = in.read(b)) != -1) { //in.read(b),返回读到的字节数，没有时返回-1
                //write(data,offset,length)
                bos.write(b, 0, n); 
                //System.out.print(n);
            }
            in.close();
            bos.close();
        } catch (Exception e) {
            System.out.print(e);
        }
        
    }

    public void init() throws ServletException {
        // Put your code here
    }

}

public class split {
    private Connection conn=null;
    private Statement stmt=null;
    private ResultSet rs=null;
    private ResultSetMetaData rsmd=null; 
    
    private String url="jdbc:mysql://localhost:3306/student?useSSL=true";
    private String useName="root";
    private String password="2277092";
    private String sqlStr;   //SQL查询语句
    private int rowCount=0;  //总记录数目
    private int pageCount=0; //所分的逻辑页数
    private int pageSize=0;  //每页显示的记录数
    
    public void setCon(){
        try{
            Class.forName("com.mysql.jdbc.Driver");
            conn=DriverManager.getConnection(url,useName,password);
            //System.out.print("加载驱动类和数据库连接成功");
        }
        catch(Exception e){
            e.printStackTrace();
        }
    }
    
    //初始化,第三个参数表示目前所显示的是第几页
    public void initialize(String sqlStr,int pageSize,int ipage){
        this.sqlStr=sqlStr;
        this.pageSize=pageSize;
        
        //检索开始位置=每页显示的记录数*(所在的页数-1)
        //实际是从第irows+1条记录开始检索
        int irows=pageSize*(ipage-1);
        
        try{
            //第一次执行SQL语句，获取所有数据库表所有信息
            stmt=this.conn.createStatement();
            rs=stmt.executeQuery(this.sqlStr); //执行SQL语句，获取MySQL里面的数据
            if(rs!=null){
                rs.last(); //将游标指向最后一行
                this.rowCount=rs.getRow();//获取当前记录所在的行数，即记录总数
                //rs.first();
                //页数总数=(总记录数目-1)/每页显示的记录数+1
                this.pageCount=(this.rowCount-1)/this.pageSize+1;
            }
            
            //第二次执行SQL语句，对数据库信息进行检索
            this.sqlStr=sqlStr+" limit "+irows+","+pageSize+";"; //检索pageSize条数据
            stmt=this.conn.createStatement();
            rs=stmt.executeQuery(this.sqlStr);
            this.rsmd=rs.getMetaData(); //获取数据库中ColumnName的信息
            //System.out.print(rsmd);
            
        }
        catch(SQLException e){
            System.out.print(e.toString());
        }
    }
    
    //将显示的结果保存到集合类中
    public Vector<Object[]> getPage(){
        Vector<Object[]> vData=new Vector<Object[]>();
        try{
            if(rs!=null){
                while(rs.next()){
                    String[] sData=new String[5];//5表示一行中属性种类的个数
                    for(int j=0;j<rsmd.getColumnCount();j++){//获取一行中有几种属性的数目
                        sData[j]=rs.getString(j+1);
                    }
                    //System.out.print(rsmd.getColumnCount());
                    vData.addElement(sData);
                }
            }
            rs.close();
            stmt.close();
        }
        catch(SQLException e){
            System.out.print(e.toString());
        }
        return vData;
    }
    
    //获取页面总数
    public int getPageCount(){
        return this.pageCount;
    }
    
    //获取数据表中记录总数
    public int getRowCount(){
        return this.rowCount;
    }
    
    //关闭数据库连接
    public void closeConn(){
        if(conn!=null){
            try {
                conn.close();
                //System.out.print("成功关闭数据库连接");
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

public class updateinfo extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private String url="jdbc:mysql://localhost:3306/student?useSSL=true";
    private String useName="root";
    private String password="2277092";
    private String sql="";
    private Connection conn=null;
    private Statement stmt=null;
    private ResultSet rs=null;

    public updateinfo() {
        super();
    }

    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    //连接数据库
    private void setConn(){
        try{
                Class.forName("com.mysql.jdbc.Driver");
                conn=DriverManager.getConnection(url,useName,password);
            }
            catch(ClassNotFoundException e){
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        setConn();
        
        request.setCharacterEncoding("gb2312");
        response.setContentType("text/html;charset=gb2312");
        String id=request.getParameter("id");
        //System.out.print(id);
        
        try {
            sql="select * from info;";
            stmt=conn.createStatement();
            rs=stmt.executeQuery(sql);
            
            while(rs.next()){
                String no=rs.getString(1);
                String name=rs.getString(2);
                String phone=rs.getString(3);
                String sex=rs.getString(4);
                String address=rs.getString(5);
                try{
                if(id.equals(no)){
                    request.setAttribute("no", no);
                    request.setAttribute("name", name);
                    request.setAttribute("phone", phone);
                    request.setAttribute("sex", sex);
                    request.setAttribute("address", address);
                    
                    RequestDispatcher dispatcher=request.getRequestDispatcher("/splitpage2/update.jsp");
                    dispatcher.forward(request, response);
                }
                }
                catch(Exception e){
                    e.printStackTrace();
                }
            }
            rs.close();
            stmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        finally{
            try{
                if(conn!=null){
                    conn.close();
                    //System.out.print("关闭数据库成功");
                }
            }
            catch(SQLException e){
                e.printStackTrace();
            }
        }
    }
    
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        setConn();
        
        request.setCharacterEncoding("gb2312");
        response.setContentType("text/html;charset=gb2312");
        
        String no=request.getParameter("no");
        String name=request.getParameter("name");
        String phone=request.getParameter("phone");
        String sex=request.getParameter("sex");
        String address=request.getParameter("address");
        //System.out.print(sex);
        
        try{
            sql="update info set name=‘"+name+"‘,phone=‘"+phone+"‘,sex=‘"+sex+"‘,address=‘"+address+"‘ where no="+no+";";
            stmt=conn.createStatement();
            
            stmt.executeUpdate(sql);
            stmt.close();
            conn.close();
            
            RequestDispatcher dispatcher=request.getRequestDispatcher("/splitpage2/list.jsp");
            dispatcher.forward(request, response);
        }
        catch(SQLException e){
            e.printStackTrace();
        }
    }

    public void init() throws ServletException {
        // Put your code here
    }

}

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<%request.setCharacterEncoding("gb2312"); %>
<%response.setContentType("text/html;charset=gb2312"); %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>添加/删除信息</title>
<style type="text/css">
    .bg{
        background:url(image/3.jpeg);
    }
</style>
</head>

<body class="bg">
    <center>
    <h1>添加与删除信息</h1><hr><br>
    <form action="servlet/addinfo" method="post">
        <table border="1" cellspacing="0" cellpadding="3">
            <tr align="right">
                <td>学号:</td>
                <td><input type="text" name="no" size="30" ></td>
            </tr>
            <tr align="right">
                <td>姓名:</td>
                <td><input type="text" name="name" size="30"></td>
            </tr>
            <tr align="right">
                <td>联系方式:</td>
                <td><input type="text" name="phone" size="30"></td>
            </tr>
            <tr align="right">
                <td>性别:</td>
                <td align="left">
                    <input type="radio" name="sex" value="男">男
                    <input type="radio" name="sex" value="女">女
                </td>
            </tr>
            <tr align="right">
                <td>地址:</td>
                <td><input type="text" name="address" size="30"></td>
            </tr>
            <tr>
                <td></td>
                <td>
                    <input type="submit" value="提交">&nbsp;
                    <input type="reset" value="重置">
                </td>
            </tr>
        </table>
    </form>
    提示：<input type="text" name="tips" value="<%=request.getAttribute("tips") %>" readonly>
    <a href="splitpage2/list.jsp">返回主页</a>
    </center>
    
    <br><br><br>
    <center>
    <form action="servlet/deleteinfo" method="post">
    请输入要删除的学号:
        <input type="text" name="no">
        <input type="submit" value="提交">
        <input type="reset" value="重置">
    </form>
    </center>
    
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<%@ page import="java.io.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>文件下载站</title>
<style type="text/css">
    .bg{
        background:url(image/3.jpeg);
    }
    .textS{
        font-size:25px;
    }
    a:hover{
        color:red;
    }
</style>
</head>

<body class="bg">
    <center>
    <font color="#00008b" size="6" >文件下载站</font><br><br>
    <table>
        <%
            path="E:\\Tomcat\\webapps\\MyWeb";
            File file=new File(path,"\\myfile");
            String str[]=file.list();
            for(int i=0;i<str.length;i++){
                String s=str[i];
                out.print("<tr class=‘textS‘><td>"+s+"</td><td><a href=‘servlet/downfile?name="+s+"‘>下载</a></td></tr>");
            } 
         %>
    </table>
    <br><br>
    <a href="splitpage2/list.jsp">返回主页</a>
    </center>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<%@page import="java.sql.*" %>
<%@page import="java.io.*" %>
<%@page import="com.*" %>
<jsp:useBean id="pages" scope="page" class="com.split"/>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>蓝霸学院名册</title>
<style type="text/css">
    .tablebg{
        width:440px;
        height:247px;
        background-color:rgba(255,255,255,0.3);
    }
    .bg{
        background:url(image/3.jpeg);
    }
    .left-message{
        float:left;
        margin-top:10px; 
    }
    .left-message-margin{
        margin-top:10px;
        margin-left:15px;
    }
    .left-message-bg{
        width:120px;
        height:230px;
        padding-left:10px;
        padding-top:10px;
        background-color:rgba(224,224,224,0.3) ;
    }
    a{
        text-decoration:none;
    }
    a:hover{
        text-decoration:underline;
        color:red;
    }
</style>
</head>

<body class="bg">
    <br>
    <!-- 标题 -->
    <center><div align="center"><h1>学员信息一览</h1></div><br></center>
    
    <!-- 友情提示 -->
    <div class="left-message left-message-bg">
    <font size="5px">友情提示:</font><br>
    <div class="left-message-margin"><a href="splitpage2/list.jsp">查看信息</a><br></div>
    <div class="left-message-margin"><a href="splitpage2/add.jsp">添加信息</a><br></div>
    <div class="left-message-margin"><a href="splitpage2/add.jsp">删除信息</a><br></div>
    <div class="left-message-margin"><a href="splitpage2/update.jsp">修改信息</a></div>
    <div class="left-message-margin"><a href="splitpage2/downfile.jsp">资料下载</a></div>
    <div class="left-message-margin"><a href="">联系客服</a></div>
    <div class="left-message-margin"><a href="">关于我们</a></div>
    </div>
    
    <%!
        String sqlStr="";
        int pageSize=5; //每页显示的记录数
        int showPage=1; //当前页
     %>    
     
     <%
         //连接数据库
         pages.setCon();
         
         //这里后面不能加";"号,因为后面还有limit 0,2;
         sqlStr="select * from info order by no";
         String strPage=null;
         strPage=request.getParameter("showPage");//获取目前显示的页数
         if(strPage==null){
             showPage=1;
         }
         else{
             try{
                 showPage=Integer.parseInt(strPage);
             }
             catch(NumberFormatException e){
                 System.out.print(e.toString());
                 showPage=1;
             }
             if(showPage<1){
                 showPage=1;
             }
         }
         
         pages.initialize(sqlStr, pageSize, showPage);
         Vector<Object[]> vData=pages.getPage();
      %>
      
      <div align="center" ><br>
      <div class="tablebg">
      <!-- 表格区 -->
      <table border="1"  cellspacing="1" cellpadding="10" >
          <tr align="center">
              <td>学号</td>
              <td>姓名</td>
              <td>联系方式</td>
              <td>性别</td>
              <td>地址</td>
          </tr>
          <%
              for(int i=0;i<vData.size();i++){
                  String[] sData=(String[])vData.get(i); //显示数据
          %>          
              <tr align="center">
                   <td width="50"><%=sData[0] %></td>
                   <td width="80"><%=sData[1] %></td>
                   <td width="150"><%=sData[2] %></td>
                   <td width="50"><%=sData[3] %></td>
                   <td width="100"><%=sData[4] %></td>
              </tr>        
          <%
              }
           %>
      </table>
      </div>
      <br>
      <br>
      <br>
      <!-- 分页区 -->
      <form action="splitpage2/list.jsp" method="get" target="_self">
        共<%=pages.getRowCount() %>条&nbsp;
        <%=pageSize %>条/页&nbsp;
        第<%=showPage %>页/共<%=pages.getPageCount() %>页&nbsp;
        <a href="splitpage2/list.jsp?showPage=1" target="_self">[首页]</a>&nbsp;
        
        <!-- 上一页   -->
        <%
            if(showPage>1){
        %>
            <a href="splitpage2/list.jsp?showPage=<%=showPage-1%>" target="_self">[上一页]</a>
        <%
            }
            else{
        %>
            [上一页]&nbsp;
        <%
            }
         %>
         
         <!-- 下一页   -->
         <%
             if(showPage<pages.getPageCount()){
         %>
             <a href="splitpage2/list.jsp?showPage=<%=showPage+1 %>" target="_self">[下一页]</a>
         <%
             }
             else{
         %>
             [下一页]&nbsp;
         <%
             }
          %>
          
          <a href="splitpage2/list.jsp?showPage=<%=pages.getPageCount()%>">[尾页]</a>&nbsp;
          
          <!-- 转到第n页 -->
             转到
          <select name="showPage">
              <%
                  for(int i=1;i<=pages.getPageCount();i++){
              %>
                  <option value="<%=i%>"
                      <%
                          if(showPage==i)
                              out.print("selected");
                       %>>
                       <%=i %>
                  </option>
              <%
                  }
               %>
          </select>
             页&nbsp;
          <input type="submit" value="跳转">
      </form>
      </div>
      <%
          pages.closeConn();
       %>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<%@page import="com.*" %>
<%request.setCharacterEncoding("gb2312"); %>
<%response.setContentType("text/html;charset=gb2312"); %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>修改信息</title>
<style type="text/css">
    .bg{
        background:url(image/3.jpeg);
    }
</style>
</head>

<body class="bg">
    <center>
        <h1>修改学员信息</h1><hr><br>
        <form action="servlet/updateinfo" method="get">
            输入要修改的学号:
            <input type="text" name="id">
            <input type="submit" value="查询">
            <input type="reset" value="重置">
        </form>
        
        <form action="servlet/updateinfo" method="post">
            <table border="1" cellspacing="0" cellpadding="3">
            <tr align="right">
                <td>学号:</td>
                <td><input type="text" name="no" size="30" value="<%=request.getAttribute("no")%>"></td>
            </tr>
            <tr align="right">
                <td>姓名:</td>
                <td><input type="text" name="name" size="30" value="<%=request.getAttribute("name")%>"></td>
            </tr>
            <tr align="right">
                <td>联系方式:</td>
                <td><input type="text" name="phone" size="30" value="<%=request.getAttribute("phone")%>"></td>
            </tr>
            <tr align="right">
                <td>性别:</td>
                <td><input type="text" name="sex" size="30" value="<%=request.getAttribute("sex")%>"></td>
            </tr>
            <tr align="right">
                <td>地址:</td>
                <td><input type="text" name="address" size="30" value="<%=request.getAttribute("address")%>"></td>
            </tr>
            <tr>
                <td></td>
                <td align="center">
                    <input type="submit" value="提交">&nbsp;
                </td>
            </tr>
        </table>
        </form>
        
        <a href="splitpage2/list.jsp">返回主页</a>
    </center>
</body>
</html>