POC199 2017-03-24 23:52 采纳率: 100%
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java加了**的部分代码看不明白,for里面的name不是会被覆盖吗,具体起到什么作用

/*

  • To change this license header, choose License Headers in Project Properties.
  • To change this template file, choose Tools | Templates
  • and open the template in the editor. */ package friendManager;

import java.sql.*;
;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.JOptionPane;
import loginRegister.LoginBean;

/**
*

  • @author 13538 */

public class UpdateFriendMessageServlet extends HttpServlet {

/**
 * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
 * methods.
 *
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
try (PrintWriter out = response.getWriter()) {
    /* TODO output your page here. You may use following sample code. */
    out.println("<!DOCTYPE html>");
    out.println("<html>");
    out.println("<head>");
    out.println("<title>Servlet UpdateFriendMessageServlet</title>");
    out.println("</head>");
    out.println("<body>");
    out.println("<h1>Servlet UpdateFriendMessageServlet at " + request.getContextPath() + "</h1>");
    out.println("</body>");
    out.println("</html>");
}
}

// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
 * Handles the HTTP <code>GET</code> method.
 *
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {

// processRequest(request, response);
String phone = new String(request.getParameter("phone").getBytes("ISO-8859-1"), "UTF-8");
String email = new String(request.getParameter("email").getBytes("ISO-8859-1"), "UTF-8");
String workplace = new String(request.getParameter("workplace").getBytes("ISO-8859-1"), "UTF-8");
String place = new String(request.getParameter("place").getBytes("ISO-8859-1"), "UTF-8");
String QQ = new String(request.getParameter("QQ").getBytes("ISO-8859-1"), "UTF-8");
if (phone.length() == 0 || email.length() == 0 || workplace.length() == 0 || place.length() == 0 || QQ.length() == 0) {
wrong1();
response.sendRedirect("http://localhost:/PIMS/friendManager/updateFriendMessage.jsp");
} else {
try {
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
Class.forName("com.mysqljdbc.Driver");
String url = "jdbc:mysql://localhost:3306/person?useUnicode=true&characterEncoding=gbk";
con = DriverManager.getConnection(url, "root", "KangU");
stmt = con.createStatement();
String userName = "";
HttpSession session = request.getSession();
ArrayList login = (ArrayList) session.getAttribute("login");
if (login == null || login.size() == 0) {
response.sendRedirect("http://localhost:8080/PIMS/login.jsp");
} else {
for (int i = login.size() - 1; i >= 0; i--) {
LoginBean nn = (LoginBean) login.get(i);
userName = nn.getUserName();
}
}

    String name = null;
    ArrayList friendslist3 = (ArrayList)session.getAttribute("friendslist3");
    if (friendslist3 == null || friendslist3.size() == 0) {
        response.sendRedirect("http://localhost:8080/PIMS/main/bottom.jsp");
    } else {
      **  for (int i = friendslist.size() - 1; i >= 0; i--) {
        UpdateFriendBean ff = (UpdateFriendBean) friendslist3.get(i);
        name = ff.getName();
        }**
    }
    String sql1 = "update friends set phone='" + phone + "', email='" + email + "', workplace='" + workplace + "', place='" + place + "', QQ='" + QQ + "' where name='" + name + "' and userName='" + userName + "'";
    stmt.executeUpdate(sql1);
    String sql2 = "select * from friends where userName='" + userName + "'";
    rs = stmt.executeQuery(sql2);
    ArrayList friendslist = null;
    friendslist = new ArrayList();
    while (rs.next()) {
        LookFriendBean ff = new LookFriendBean();
        ff.setName(rs.getString("name"));
        ff.setPhone(rs.getString("phone"));
        ff.setEmail(rs.getString("email"));
        ff.setWorkplace(rs.getString("workplace"));
        ff.setPlace(rs.getString("place"));
        ff.setQQ(rs.getString("QQ"));
        friendslist.add(ff);
        session.setAttribute("friendslist", friendslist);
    }
    rs.close();
    stmt.close();
    con.close();
    right();
    response.sendRedirect("http://localhost:8080/PIMS/friendMessager/LookFriendServlet.jsp");
    } catch (Exception e) {
    e.printStackTrace();
    }
}

/**
 * Handles the HTTP <code>POST</code> method.
 *
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
@Override
protected void doPost
(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
    doGet(request, response);
}

/**
 * Returns a short description of the servlet.
 *
 * @return a String containing servlet description
 */
@Override
public String getServletInfo

    () {
return "Short description";
}// </editor-fold>





public void wrong1() {
String msg = "不允许有空,添加失败";
int type = JOptionPane.YES_NO_CANCEL_OPTION;
String title = "信息提示";
JOptionPane.showMessageDialog(null, msg, title, type);
}

public void right() {
String msg = "填写信息及格,添加成功";
int type = JOptionPane.YES_NO_CANCEL_OPTION;
String title = "信息提示";
JOptionPane.showMessageDialog(null, msg, title, type);
}

}

  • 写回答

1条回答 默认 最新

  • POC199 2017-03-24 23:54
    关注

    if (friendslist3 == null || friendslist3.size() == 0) {
    response.sendRedirect("http://localhost:8080/PIMS/main/bottom.jsp");
    } else {
    ** for (int i = friendslist.size() - 1; i >= 0; i--) {
    UpdateFriendBean ff = (UpdateFriendBean) friendslist3.get(i);
    name = ff.getName();
    }**
    }

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

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  • 已采纳回答 12月14日

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