java web遇到的各种问题汇总

1.异常：十二月 12, 2015 5:06:31 下午 org.apache.catalina.core.StandardWrapperValve invoke

SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/BSMD] threw exception [Handler processing failed; nested exception is java.lang.OutOfMemoryError: Java heap space] with root cause

java.lang.OutOfMemoryError: Java heap space

源代码：

for(int index=0;index<<span style="color:#FF0000;">userPosStamplist.size()</span>;index++){
UserPosStamp posStampInfo= userPosStamplist.get(index);
String stampStartDate = new SimpleDateFormat("yyyy-MM-dd").format(posStampInfo.getStampStartDate());
String stampEndDate = new SimpleDateFormat("yyyy-MM-dd").format(posStampInfo.getStampEndDate());
posStampInfo.setStartDate(stampStartDate);
posStampInfo.setEndDate(stampEndDate);
<span style="color:#FF0000;"> userPosStamplist.add(posStampInfo);</span>
}

解释：因为用了add()方法，所以size()会增加，因此陷入死循环

解决方案：用set方法

解决方案：用set方法
<span style="color:#000000;">userPosStamplist.set(index, posStampInfo);</span>
2.ClassCastException:



解决方案：用set方法