ajax+struts报java.lang.IllegalStateException请高手指教

[chrisl8080]

JS
function getResult(stateVal)
{
var url = "./sample.do?method=changeAjax";
if(window.XMLHttpRequest)
{
req = new XMLHttpRequest();
}else if(window.ActiveXObject)
{
req = new ActiveXObject("Microsoft.XMLHTTP");
}
if(req)
{
req.open("GET",url,true);
req.onreadystatechange = complete;
req.send(null);
}
}
function complete()
{
if(req.readyState == 4)
{
if(req.status == 200)
{
var city = req.responseXML.getElementsByTagName("city");
//alert(city.length);
var str = new Array();
for(var i=0;i<city.length;i++)
{
str[i] = city[i].firstChild.data;
}
alert(document.getElementById("city"));
buildSelect(str,document.getElementById("city"));
}
}
}
function buildSelect(str,sel)
{
sel.options.length=0;
for(var i=0;i<str.length;i++)
{
sel.options[sel.options.length] = new Option(str[i],str[i])
}
}


JSP
<select name="state" onChange="getResult(this.value)">
<option value="">selsect</option>
<option value="zj">zj</option>
<option value="zs">js</option>
</select>

<select id="city"></select>

ACTION
response.setContentType("text/xml");
response.setCharacterEncoding("UTF-8");
response.setHeader("Cache-Control","no-cache");
String state = request.getParameter("state");
StringBuffer sb = new StringBuffer("<state>");
if("zj".equals(state))
{
sb.append("<city>hz1</city><city>hz2</city>");

}else if("zs".equals(state))
{
sb.append("<city>nj</city><city>yz</city><city>sz</city>");
}
sb.append("</state>");
PrintWriter out = response.getWriter();
out.write(sb.toString());
out.close();
我觉得是ACTION中的问题,是不是和STRUTS中的response有冲突,请问应该怎么解决.谢谢.

[街头小贩]

是不是和STRUTS中的response有冲突
re:
不可能！我写过很多还没有发现!你告诉我:request.getParameter("state");
state的值从哪得来?
是这吗?==>var url = "./sample.do?method=changeAjax";

[街头小贩]

你在java.lang包下看一看:
public class IllegalStateException extends RuntimeException
在非法或不适当的时间调用方法时产生的信号。换句话说，即 Java 环境或 Java 应用程序没有处于请求操作所要求的适当状态下。

[chrisl8080]

TO xiaofanku
从request.getParameter("state");中得到state的值.

[falcon272003]

var url = "./sample.do?method=changeAjax&state="+stateVal;

[chrisl8080]

能把二级下拉列表读出来,但是还是报java.lang.IllegalStateException:错误,请问哪里出的这个错误,现在看来ACTION中应该没什么问题,因为我每行都输出一个字符,知道最后都没什么问题,应该怎么改呢.

[老紫竹]

java.lang.IllegalStateException

可以肯定是Java方面的问题。你的异常不完整，无法判断具体原因。

response.setContentType("text/xml");
response.setCharacterEncoding("UTF-8");
response.setHeader("Cache-Control","no-cache");

这几句之前不能有任何输出，否则会有异常出来。

仔细看看异常里面到底是哪一行的问题

[chrisl8080]

前面没有任何输出
完整的异常是
java.lang.IllegalStateException:
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:302)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292)
at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1063)
at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:386)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:229)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at jp.co.lce.waf.utils.EncodingFilter.doFilter(EncodingFilter.java:25)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)

[老紫竹]

at jp.co.lce.waf.utils.EncodingFilter.doFilter(EncodingFilter.java:25)

我看你先把这个过滤器屏蔽掉，运行看看异常信息吧。

[街头小贩]

你的URL和4楼提供的一样么?