步骤三： ActionServlet保持不变
步骤四： 运行，查看结果
6.4 完整代码
regist01.html文件代码如下：
<html>
<head>
<title>regist01.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="js/my.js"></script>
<script type="text/javascript">
function check_name(){
var uname = document.getElementById("uname");
var uri = "check_name.do?uname="+uname.value;
var xhr = getXhr();
xhr.onreadystatechange=function(){
if(xhr.readyState==4 && xhr.status==200){
document.getElementById("name_msg").innerHTML
= xhr.responseText;
}
};
xhr.open("get",encodeURI(uri),true);
document.getElementById("name_msg").innerHTML="正在检查。。。";
xhr.send(null);
}
</script>
</head>
<body>
<!-- GET方式提交中文用户名进行验证 -->
<form action="" method="post">
<fieldset>
<legend>注册信息</legend>
用户名：<input name="uname" id="uname"/>
<input type="button" value="检查一下吧" onclick="check_name()"/>
<span id="name_msg" style="color:red;"></span>
<br/><br/>
<input type="submit" value="注册"/>
</fieldset>
</form>
</body>
</html>
ActionServlet.java文件代码如下：
package web;
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 ActionServlet extends HttpServlet {
public void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
request.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
// 获取请求资源路径
String uri = request.getRequestURI();
String path = uri.substring(uri.lastIndexOf("/"), uri.lastIndexOf("."));
if (path.equals("/get_text")) {// get请求
out.println("get请求-服务器返回的数据");
} else if (path.equals("/post_text")) {// post请求
String name = request.getParameter("uname");
System.out.println(name);
out.println("又来了一次的" + name);
} else if (path.equals("/check_name")) {// 检查用户名
String name = request.getParameter("uname");
// 模拟网络延迟的操作
if (1 == 1) {
try {
Thread.sleep(6000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println(name);
if ("Luffy".equals(name)) {
out.println("该用户名不可用");
} else {
out.println("可以使用！");
}
}
out.close();
}
}
