Ajaxプログレスバーを表示
6762 ワード
ファイル一覧 progressBar. Progess BarServlet.java プログレスBar.
<!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=UTF-8">
<title>Ajax Progress Bar</title>
<script type="text/javascript">
var xmlHttp;
var key;
var bar_color = 'gray';
var span_id = 'block';
var clear = " "
function createXMLHttpRequest() {
if (window.ActiveXObject) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {
xmlHttp = new XMLHttpRequest();
}
}
function go() {
createXMLHttpRequest();
checkDiv();
var url = "ProgressBarServlet?task=create";
var button = document.getElementById("go");
button.disabled = true;
xmlHttp.open("GET",url,true);
xmlHttp.onreadystatechange = goCallback;
xmlHttp.send(null);
}
function goCallback() {
if (xmlHttp.readyState == 4) {
if (xmlHttp.status == 200) {
setTimeout("pollServer()",2000);
}
}
}
function pollServer() {
createXMLHttpRequest();
var url = "ProgressBarServlet?task=poll&key="+key;
var button = document.getElementById("go");
button.disabled = true;
xmlHttp.open("GET",url,true);
xmlHttp.onreadystatechange = pollCallback;
xmlHttp.send(null);
}
function pollCallback() {
if (xmlHttp.readyState == 4) {
if (xmlHttp.status == 200) {
var percent_complete = xmlHttp.responseXML.
getElementsByTagName("percent")[0].firstChild.data;
var index = processResult(percent_complete);
for(var i=1;i<=index;i++) {
var elem = document.getElementById("block"+i);
elem.innerHTML = clear;
elem.style.backgroundColor = bar_color;
var next_cell = i+1;
if (next_cell > index && next_cell <=9) {
document.getElementById("block"+next_cell).innerHTML = percent_complete+"%";
}
}
if (index < 9) {
setTimeout("pollServer()",2000);
} else {
document.getElementById("complete").innerHTML="Complete!";
document.getElementById("go").disabled=false;
}
}
}
}
function processResult(percent_complete) {
var ind;
if (percent_complete.length == 1) {
ind = 1;
} else if (percent_complete.length ==2) {
ind = percent_complete.substring(0,1);
} else {
ind = 9;
}
return ind;
}
function checkDiv() {
var progress_bar = document.getElementById("progressBar");
if (progress_bar.style.visibility == "visible") {
clearBar();
document.getElementById("complete").innerHTML = "";
} else {
progress_bar.style.visibility = "visible";
}
}
function clearBar() {
for (var i=1;i<10;i++) {
var elem = document.getElementById("block"+i);
elem.innerHTML = clear;
elem.style.background = "white";
}
}
</script>
</head>
<body>
<h1>Ajax Progress Bar Example</h1>
Launch long-running process:
<input type="button" value="Launch" id="go" onclick="go();" />
<br/>
<table align="center">
<tbody>
<tr>
<td>
<div id="progressBar" style="padding:2px;border:solid black 2px;visibility:hidden">
<span id="block1"> </span>
<span id="block2"> </span>
<span id="block3"> </span>
<span id="block4"> </span>
<span id="block5"> </span>
<span id="block6"> </span>
<span id="block7"> </span>
<span id="block8"> </span>
<span id="block9"> </span>
</div>
</td>
</tr>
<tr><td align="center" id="complete"></td></tr>
</tbody>
</table>
</body>
</html>
プログレスBarServlet.javapackage ajaxbook.chap4;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ProgressBarServlet extends HttpServlet {
private int counter = 1;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String task = req.getParameter("task");
String res = "";
if (task.equals("create")) {
res = "<key>1</key>";
counter = 1;
} else {
String percent = "";
switch(counter) {
case 1:percent = "10";break;
case 2:percent = "23";break;
case 3:percent = "35";break;
case 4:percent = "51";break;
case 5:percent = "64";break;
case 6:percent = "73";break;
case 7:percent = "89";break;
case 8:percent = "100";break;
}
counter++;
res = "<percent>"+percent+"</percent>";
}
PrintWriter out = resp.getWriter();
resp.setContentType("text/xml");
resp.setHeader("Cache-Control", "no-cache");
out.println("<response>");
out.println(res);
out.println("</response>");
out.close();
}
}
運転効果は下図の通りです。