- 博客(0)
- 资源 (2)
- 问答 (6)
- 收藏
- 关注
java练习题
初学java的可以边学边练,效果盛佳!
3 编程题(改代码,写代码)
3.1 下拉列表实现
使用ajax技术完成下拉列表对应显示内容。
当选择下拉列表某项时:
显示对应内容:
参考答案:
1)ActionServlet
copytextpop-up
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 { request.setCharacterEncoding("utf-8"); String uri = request.getRequestURI(); String path = uri.substring(uri.lastIndexOf("/"), uri.lastIndexOf(".")); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); if(path.equals("/prod")){ String name = request.getParameter("name"); System.out.println("name:" + name); if(name.equals("qq")){ out.println("性价比高"); }else if(name.equals("bmw")){ out.println("驾驶性能出众"); }else{ out.println("好车,也贵"); } } out.close(); } }
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 {
request.setCharacterEncoding("utf-8");
String uri = request.getRequestURI();
String path = uri.substring(uri.lastIndexOf("/"),
uri.lastIndexOf("."));
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
if(path.equals("/prod")){
String name = request.getParameter("name");
System.out.println("name:" + name);
if(name.equals("qq")){
out.println("性价比高");
}else if(name.equals("bmw")){
out.println("驾驶性能出众");
}else{
out.println("好车,也贵");
}
}
out.close();
}
}
2)product.jsp
copytextpop-up
<%@ page contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <html> <head> <title>Insert title here</title> <style> #d1{ background-color:#fff8dc; width:220px; } </style> <script type="text/javascript" src="js/prototype-1.6.0.3.js"> </script> <script type="text/javascript"> function getXmlHttpRequest(){ var xhr = null; if((typeof XMLHttpRequest)!='undefined'){ xhr = new XMLHttpRequest(); }else { xhr = new ActiveXObject('Microsoft.XMLHttp'); } return xhr; } function change(v1){ var xhr = getXmlHttpRequest(); xhr.open('get','prod.do?name='+v1,true); xhr.onreadystatechange=function(){ if(xhr.readyState == 4){ var txt = xhr.responseText; $('d1').innerHTML = txt; } } xhr.send(null); } </script> </head> <body style="font-size:30px;"> <select style="width:120px;" id="s1" onchange="change(this.value);"> <option value="qq">QQ</option> <option value="bmw">宝马</option> <option value="ff">法拉利</option> </select> <div id="d1"></div> </body> </html>
2013-11-11
谁精通JFinal,可以讲解一下里面的东西吗?急!急!急!急!急!急!急!
2014-08-21
JFinal中做登录该如何做登录部分,网上有的看不懂
2014-08-21
基于C#,我想做一个程序打开的缓冲界面,求代码
2013-12-10
求大神指点c#winform中的picturebox的tag属性的应用
2013-12-10
c#winform中的云台控制的设计以及他的按钮设计
2013-11-18
TA创建的收藏夹 TA关注的收藏夹
TA关注的人