2
を受け取ることができません。私はサーバーから応答を受け取る際に問題があります（応答 'status' 0）。私は提案されたリストの類似の問題を参照して、すでに試してみましたが、問題は依然として続きます。誰かが私のAJAXコードで間違っていることを指摘してくれることを願っています。AJAXは - 私は私の学校のプロジェクトのための初めてのAJAXをしようとしていますサーブレット応答
は、ここに私のJSPコードです：
<%@ page import="java.io.IOException"%>
<%@ page import="java.sql.SQLException"%>
<%@ page import="java.sql.Connection"%>
<%@ page import="java.sql.ResultSet"%>
<%@ page import="java.sql.Statement"%>
<%@ page import="com.p6qgen.*"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Generate Question</title>
<link rel="stylesheet" type="text/css" href="style.css" />
<script type="text/javascript" src="js/jquery-1.6.2.js"></script>
</head>
<body>
<script language="javascript" type="text/javascript">
<!--
// Checking whether the browser support AJAX or not
function ajaxFunction() {
var ajaxReq; // The variable to hold XMLHttpRequest object
//alert("ajaxFunction()");
try {
// Chrome, Firefox, Opera, Safari
ajaxReq = new XMLHttpRequest();
} catch (e){
// Internet Explorer Browsers
try{
ajaxReq = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try{
ajaxReq = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e){
// Something went wrong
alert("Your browser does not support AJAX!");
return false;
}
}
}
//alert("Ajax object created...");
/*
* Start of server response handling
*/
ajaxReq.onreadystatechange = parseXml;
// Parsing the xml document
function parseXml() {
if(ajaxReq.readyState == 4){
alert("in parseXml");
if(ajaxReq.status == 200) {
alert("Status OK!");
var numQs = ajaxReq.responseXML.getElementsByTagName("numqs")[0];
alert(numQs);
for(var i=0; i<numQs; i++) {
num = i+1;
var question = ajaxReq.responseXML.getElementsByTagName("question")[i];
setQuestion(num, question.childNodes[0].nodeValue);
}
} else if(ajaxReq.status == 404) {
alert("Page Not Found");
} else {
alert("Error: " + ajaxReq.status)
}
}
/* Just for debugging
else {
switch(ajaxReq.readyState) {
case 0: alert("Not Initialize"); break;
case 1: alert("Connection Establish"); break;
case 2: alert("Request received"); break;
case 3: alert("Answer in Progress"); break;
}
} */
}
/*function setQuestion(num, question) {
var qsTag = document.getElementById("question");
var qBody = "<font size=\"4\"> Question " + num;
qBody += "<p>" + question +"</p></font>";
// if the messageBody element has been created simple replace it otherwise
// append the new element
if (qsTag.childNodes[0]) {
qsTag.replaceChild(qBody, qsTag.childNodes[0]);
} else {
qsTag.appendChild(qBody);
}
}*/
/*
* End of server response handling
*/
// Extract selected values from dropdown lists and store in corresponding var
alert("going to show...");
var numT01 = document.getElementById('numT01').value;
var numT02 = document.getElementById('numT02').value;
var numT03 = document.getElementById('numT03').value;
var numT04 = document.getElementById('numT04').value;
var numT05 = document.getElementById('numT05').value;
var numT06 = document.getElementById('numT06').value;
var numT07 = document.getElementById('numT07').value;
var numT08 = document.getElementById('numT08').value;
// Prepare query string
var queryStr = "?num1=" + numT01 + "&num2=" + numT02 + "&num3=" + numT03 +
"&num4=" + numT04 + "&num5=" + numT05 + "&num6=" + numT06 +
"&num7=" + numT07 + "&num8=" + numT08;
alert("dbg#" + numT01);
// Send request to server (server-side 'QGenerator')
ajaxReq.open("GET", "QGenerator" + queryStr, true);
//ajaxReq.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
//ajaxReq.setRequestHeader("Content-length", queryStr.length);
//ajaxReq.setRequestHeader("Connection", "close");
ajaxReq.send(null);
}
//-->
</script>
<h1 align="center">Percentage Question</h1>
<br>
<form name="qtype">
<table width="800" cellspacing="5" align="center">
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt1.jpg" width="96" height="30" name="typ1">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT01">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt2.jpg" width="96" height="30" name="typ2">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT02">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt3.jpg" width="96" height="30" name="typ3">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT03">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt4.jpg" width="96" height="30" name="typ4">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT04">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt5.jpg" width="96" height="30" name="typ5">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT05">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt6.jpg" width="96" height="30" name="typ6">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT06">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt7.jpg" width="96" height="30" name="typ7">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT07">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr>
<td width="200" align="right" valign="middle">
<input type="image" src="Pix/qt8.jpg" width="96" height="30" name="typ8">
</td >
<td align="center" valign="middle">
<font size="4">
No of Questions to generate:
<select id="numT08">
<option value="0" selected="selected">0</option>
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
</select>
</font>
</td>
</tr>
</table>
<br><br>
<table align="center">
<tr>
<td align="center" valign="middle">
<font size="4">
No of Questions to generate per page:
<select id="numQs_page">
<option value="5">5</option>
<option value="10">10</option>
<option value="20">20</option>
</select>
</font>
</td>
</tr>
<tr><td></td></tr>
<tr><td></td></tr>
<tr>
<td align="center" valign="middle">
<button onclick="ajaxFunction()">
<img src="Pix/genQs.jpg" width= "252" height="50" />
</button>
</td>
</tr>
</table>
</form>
<div id="question"></div>
</body>
そして、ここに私のサーブレットのコードは次のとおりです。非常に長いコードを投稿するための
package com.p6qgen;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
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 org.apache.velocity.runtime.log.Log;
/**
* Servlet implementation class QGenerator
*/
@WebServlet("/QGenerator")
public class QGenerator extends HttpServlet {
private static final long serialVersionUID = 1L;
DBAccess dbAccess;
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
//int num1, num2, num3, num4, num5, num6, num7, num8, total_qs;
/**
* @see HttpServlet#HttpServlet()
*/
public QGenerator() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/xml");
response.setHeader("Access-Control-Allow-Origin", "*");
try {
dbAccess = new DBAccess();
conn = dbAccess.getConnection();
stmt = conn.createStatement();
dbAccess.clearTable(conn, "T_Temp");
dbAccess.clearTable(conn, "T_Question");
//int num1 = 5;
int num1 = Integer.parseInt(request.getParameter("num1"));
int num2 = Integer.parseInt(request.getParameter("num2"));
int num3 = Integer.parseInt(request.getParameter("num3"));
int num4 = Integer.parseInt(request.getParameter("num4"));
int num5 = Integer.parseInt(request.getParameter("num5"));
int num6 = Integer.parseInt(request.getParameter("num6"));
int num7 = Integer.parseInt(request.getParameter("num7"));
int num8 = Integer.parseInt(request.getParameter("num8"));
int total_qs = num1+num2+num3+num4+num5+num6+num7+num8;
System.out.println(total_qs);
System.out.println("num1: " + num1);
int tbl_cnt = 0; // to count the solution tables created
// Generating the question
do {
if(num1!=0) {
T_Q01 q01 = new T_Q01();
q01.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q01.generateSol();
num1--;
total_qs--;
}
if(num2!=0) {
T_Q02 q02 = new T_Q02();
q02.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q02.generateSol();
num2--;
total_qs--;
}
if(num3!=0) {
T_Q03 q03 = new T_Q03();
q03.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q03.generateSol();
num3--;
total_qs--;
}
if(num4!=0) {
T_Q04 q04 = new T_Q04();
q04.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q04.generateSol();
num4--;
total_qs--;
}
if(num5!=0) {
T_Q05 q05 = new T_Q05();
q05.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q05.generateSol();
num5--;
total_qs--;
}
if(num6!=0) {
T_Q06 q06 = new T_Q06();
q06.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q06.generateSol();
num6--;
total_qs--;
}
if(num7!=0) {
T_Q07 q07 = new T_Q07();
q07.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q07.generateSol();
num7--;
total_qs--;
}
if(num8!=0) {
T_Q08 q08 = new T_Q08();
q08.generateQuestion();
tbl_cnt++;
String tbl_name = "T_S" + tbl_cnt;
dbAccess.dropTable(conn, tbl_name); // delete table if existed
dbAccess.createTable(conn, tbl_name); // created a new table
q08.generateSol();
num8--;
total_qs--;
}
} while (total_qs > 0);
// Counting total number of questions in T_Question table
int row = dbAccess.countRow(conn, "Q_ID", "T_Question");
response.getOutputStream().println("<?xml version=\"1.0\"?>");
response.getOutputStream().println("<qpage>");
response.getOutputStream().println("<numqs>");
response.getOutputStream().println(row);
response.getOutputStream().println("</numqs>");
for(int i=0; i<row; i++) {
int q_id = i+1;
response.getOutputStream().println("<number>");
response.getOutputStream().println(q_id + ".");
response.getOutputStream().println("</number>");
response.getOutputStream().println("<question>");
String q_val = dbAccess.selectValue(conn, "Q_Val", "T_Question", "Q_ID", q_id);
response.getOutputStream().println(q_val);
response.getOutputStream().println("</question>");
}
response.getOutputStream().println("</qpage>");
response.getOutputStream().flush();
response.getOutputStream().close();
stmt.close();
conn.close();
} catch(SQLException e) {
System.err.println("-----SQLException-----");
System.err.println("doGet Error: " + e.getSQLState());
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
}
申し訳ありませんが、私は、これはに良い情報を与えるかもしれないと思います私の問題を分析してください。
response.setHeader("Access-Control-Allow-Origin", "*");
をしかし、これはまだ問題が解決しない：「BalusC」として
はポスト「AJAX要求にサーブレット応答が空である」で、私はすでに含めるようにしようとしましたが示唆されました。よろしくお願いします。
おかげで、男！問題を解決しました。ステータスの返信が「200」になりました。申し訳ありませんが、私は投票権がありません。 Btw、なぜ私は '返品偽'を追加する必要がありますか？ – nyeinzay
'return false;'は、ブラウザが送信ボタンのデフォルトの動作であるフォームを送信しないようにします。 – Andreas
ありがとう、john_doe、その説明。 – nyeinzay