requtst.setAttribute("train",trains);
trains是list，里面放三个Train实体，Train有number，speed等属性怎么在函数中遍历出每个trains，并获取出属性值，如speed=？
<script Language="javascript">
function getValue
{
.........
document.write("<%=request.getAttribute("traintrack")%>") //只能获取到一个字符串 }
</script>
trains是list，里面放三个Train实体，Train有number，speed等属性怎么在函数中遍历出每个trains，并获取出属性值，如speed=？
<script Language="javascript">
function getValue
{
.........
document.write("<%=request.getAttribute("traintrack")%>") //只能获取到一个字符串 }
</script>
试试，我也不知道行不行。
<script Language="javascript">
function getValue
{
.........
// document.write("<%=request.getAttribute("traintrack")%>") //只能获取到一个字符串
var array = ${requestScope.trantrack};
alert(array.length);
for(var i in array){
alert(array[i]);
}
}
</script>
<script Language="javascript">
function getValue() // 加个 （）
{
.........
// document.write("<%=request.getAttribute("traintrack")%>") //只能获取到一个字符串
var array = ${requestScope.trantrack};
alert(array.length);
for(var i in array){
alert(array[i]);
}
}
</script>
网上抄的,自己多baidu啊function GetUrlParms()
{
var args=new Object();
var query=location.search.substring(1);//获取查询串
var pairs=query.split("&");//在逗号处断开
for(var i=0;i<pairs.length;i++)
{
var pos=pairs[i].indexOf('=');//查找name=value
if(pos==-1) continue;//如果没有找到就跳过
var argname=pairs[i].substring(0,pos);//提取name
var value=pairs[i].substring(pos+1);//提取value
args[argname]=unescape(value);//存为属性
}
return args;
}
1.对象 如果是String var v = "<%=request.getAttribute("traintrack")%>";如果是定义的对象 例如： class A{private String a1;private int a2;//get set方法自己写吧。} 那你可以：
function a(a1,b1){
this.a1 =a1;
this.b1 = b1;
}
var v = new a("<%=(A)(request.getAttribute("traintrack")).getA1()%>","<%=(A)(request.getAttribute("traintrack")).getA2()%>")2 数组 List 方法差不多。都是遍历数组或List， 在JS定义相同结构的数据存储单元，将JAVA的数年转为JS的数据。
注意： JAVA---> JS 都是通过字符串进行转化的。
不过数组有好的转化方法， 就是在后台把数据拼成[1,2,3] 这样的形式。在页面就可以直接这样写了： var v = request.getAttribute("traintrack");最后建议LZ用JSTL， 直接在JSp中用JAVA是不好的行为。
1.对象 如果是String var v = "<%=request.getAttribute("traintrack")%>";如果是定义的对象 例如： class A{private String a1;private int a2;//get set方法自己写吧。} 那你可以：
function a(a1,b1){
this.a1 =a1;
this.b1 = b1;
}
var v = new a("<%=(A)(request.getAttribute("traintrack")).getA1()%>","<%=(A)(request.getAttribute("traintrack")).getA2()%>")2 数组 List 方法差不多。都是遍历数组或List， 在JS定义相同结构的数据存储单元，将JAVA的数年转为JS的数据。
注意： JAVA---> JS 都是通过字符串进行转化的。
不过数组有好的转化方法， 就是在后台把数据拼成[1,2,3] 这样的形式。在页面就可以直接这样写了： var v = request.getAttribute("traintrack");最后建议LZ用JSTL， 直接在JSp中用JAVA是不好的行为。
traintrack就那个train，里面的是多个Train类得List，
想取到里面每个Train类得属性
测试通过了index.jsp<%@ page language="java" import="java.util.*,com.servlet.bean" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body> <script type="text/javascript">
<%
ArrayList list = (ArrayList)request.getAttribute("list");
for(int i=0;i<list.size();i++){
bean Bean = (bean)list.get(i);
%>
var name = '<%=Bean.getName()%>'
alert(name);
<%
}
%>
</script>
</body>
</html>
servlet.javapackage com.servlet;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;public class servlet extends HttpServlet {
public servlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
bean Bean = new bean();
Bean.setName("liubin");
Bean.setPwd("123");
bean Bean2 = new bean();
Bean2.setName("aaa");
Bean2.setPwd("456");
bean Bean3 = new bean();
Bean3.setName("bbb");
Bean3.setPwd("789");
ArrayList list = new ArrayList();
list.add(Bean);
list.add(Bean2);
list.add(Bean3);
request.setAttribute("list", list);
request.getRequestDispatcher("../index.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request ,response);
}
public void init() throws ServletException {
// Put your code here
}}
ArrayList list = (ArrayList)request.getAttribute("list");
这句我想放在
function（）
{
}中，老出错，怎么写，格式不对吗？
<%@ page language="java" import="java.util.*,com.servlet.bean" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body> <script type="text/javascript">
function init(){
<%
ArrayList list = (ArrayList)request.getAttribute("list");
for(int i=0;i<list.size();i++){
bean Bean = (bean)list.get(i);
%>
var name = '<%=Bean.getName()%>'
alert(name);
<%
}
%>
}
init();
</script>
</body>
</html>
函数里可以用<%%>标签吗？
那是html标签吧
有错啊
愁~~
Request = {
QueryString : function(item){
var svalue = location.search.match(new RegExp("[\?\&]" + item + "=([^\&]*)(\&?)","i"));
return svalue ? svalue[1] : svalue;
}
}
Request.QueryString("参数")
</script>
ArrayList list = (ArrayList)request.getAttribute("traintrack");
把 function 括号看仔细啊，
<script type="text/javascript">
function init(){
<%
ArrayList list = (ArrayList)request.getAttribute("list");
for(int i=0;i<list.size();i++){
bean Bean = (bean)list.get(i);
%>
var name = '<%=Bean.getName()%>'
alert(name);
<%
}
%>
}
init();
</script>
{
document.write("---------");
<%
ArrayList list = (ArrayList)request.getAttribute("traintrack");
for(int i=0;i<list.size();i++){ //80行
Train Bean = (Train)list.get(i);
%>
var name = '<%=Bean.getNumber()%>'
document.write(name);
<%
}
%>
}
错误：
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /traintrack1.jsp at line 80
77:
78: <%
79: ArrayList list = (ArrayList)request.getAttribute("traintrack");
80: for(int i=0;i<list.size();i++){
81: Train Bean = (Train)list.get(i);
82: %>
83: var name = '<%=Bean.getNumber()%>' org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:555)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause java.lang.NullPointerException
org.apache.jsp.traintrack1_jsp._jspService(traintrack1_jsp.java:148)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:390)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.2 logs.