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萌新求助啊,各位大神帮忙看看,估计是很简单很丢脸的问题。。

只看楼主收藏回复

是这样的
在学习AJAX的小白,现在发现AJAX传值到后台一直报空指针,各位大神能帮忙看看是什么问题吗?谢谢啦!!!
PS:在action中设置固定值的话,能正常运行到结束并返回前台
但是正常收的话在String Ggid=request.getParameter("ggid");这句的时候就报空指针
我现在前台AJAX代码参数写死了,action拿还是空指针,大神们帮忙看看解决一下是什么问题,谢谢啦!!(づ ̄ 3 ̄)づ
下面开始贴代码,其实在CSDN论坛上发过了不过没人回答。
下面JS部分:
<script type="text/javascript">
$(document).ready(function(){
var gid= '<%=request.getParameter("gid")%>';
//messager.alert('提示','ggid:'+ggid,'info');
//alert(gid);
$("#ggid").attr("value" , gid);
alert($("input[name=ggid]").val());
$.ajax({
type:"post",
url:"m0101/GetGgDetailAction.action",
data: {ggid:"7"},
dataType:"json",
success:function(data){
var d = eval("("+data+")");
//alert(d.content);
$('#title').textbox({
value:d.title
});
$('#date').textbox({
value:d.author_date
});
$('#author').textbox({
value:d.author
});
$('#txtdetail').textbox({
value:d.content
});
},
error:function(){
$.messager.alert('提示','获取数据出错!','info');
}
});
});
</script>
下面ACTION部分:
public String GetGgDetail(){
try{
String Ggid=request.getParameter("ggid");
//String Ggid="5";
JfInfo info=m0101service.getGgDetail(Ggid);
Map<String,Object> map = new HashMap<String,Object>();
map.put("id", info.getId());
map.put("title",info.getTitle());
map.put("content", info.getContent());
map.put("author", info.getAuthor());
map.put("author_date", info.getAuthorDate());
JSONObject json = JSONObject.fromObject(map);
result = json.toString();
}catch(Exception ex){
ex.printStackTrace();
return ERROR;
}
return SUCCESS;
}


IP属地:上海1楼2015-02-28 13:03回复
    java.lang.NullPointerException
    at com.testweb.module.m0101.action.M0101GetGgDetail.GetGgDetail(M0101GetGgDetail.java:50)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:452)
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:254)
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:133)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:142)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:166)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:485)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
    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:230)
    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:104)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:619)
    补上错误信息


    IP属地:上海2楼2015-02-28 13:04
    回复
      看过如果不能帮忙回答的,麻烦帮忙顶一下可以吗?好急的。


      IP属地:上海3楼2015-02-28 13:12
      收起回复
        csdn都没人的话 不是我打击你 这里可能性更低了 不过帮你顶下还是可以的


        4楼2015-02-28 13:22
        回复
          Ggid,info 用debug看下,哪个是null不就清楚了


          IP属地:浙江6楼2015-02-28 13:32
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            public String GetGgDetail(HttpServletRequest request){...
            大哥,应该这样写,服了


            IP属地:浙江7楼2015-02-28 13:57
            回复
              在前台chrome的控制台里调试一下看看数据有没有发送出去,再到后台看看这个参数接收到没


              IP属地:浙江8楼2015-02-28 14:00
              收起回复
                request是不是null,你debug看一下,struts2中获取request的方式用这个试试HttpServletRequest request = ServletActionContext.getRequest();


                IP属地:北京9楼2015-02-28 14:01
                收起回复