日常問題記錄-- java.util.NoSuchElementException

問題：

調用list時報錯。

type Exception report

message java.util.NoSuchElementException

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.util.NoSuchElementException
	com.paipai.webframework.dispatcher.PaiPaiDispatcher.serviceAction(PaiPaiDispatcher.java:713)
	org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:419)
	com.paipai.webframework.filter.PaiPaiDispatcherFilter.doFilter(PaiPaiDispatcherFilter.java:175)
	org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:99)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

root cause

java.util.NoSuchElementException
	java.util.ArrayList$Itr.next(ArrayList.java:834)
	webbench.web.action.WebBenchAction.QueryTaskDetail(WebBenchAction.java:167)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	java.lang.reflect.Method.invoke(Method.java:606)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:404)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:267)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:229)
	com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:221)

 

代碼：

else{
			jsonRootMap.put("ret", 0);
			jsonRootMap.put("msg", "查詢任務成功。");
			/*解析返回包*/
			Iterator<WebBenchTask> i = webbenchtasklist.iterator();
			while (i.hasNext()){
				jsonTaskMap.put("TaskId", i.next().getTaskId());
				jsonTaskMap.put("User", i.next().getUser());
				jsonTaskMap.put("Ip", i.next().getIp());

　　

 

問題原因：

i.next()每執行一次，游標后移以為。上述循環造成越界；

解決辦法：

Iterator<WebBenchTask> i = webbenchtasklist.iterator();
            while (i.hasNext()){
                WebBenchTask task = i.next();
                jsonTaskMap.put("TaskId", task.getTaskId());
                jsonTaskMap.put("User", task.getUser());
                jsonTaskMap.put("Ip", task.getIp());
                jsonTaskMap.put("Url", task.getUrl());