Dear Tomcat organization:
I think I find a bug in tomcat, I explain it in the document.The document
is in the attachment. Or I paste it directly following:
When I use logic:iterator(struts) labels in tomcat 4.1.x or later
version(5.x,6.x), I find a problem. This problem don’t appear in tomcat
4.0.x.
First of all,I will show you the test code:
<!--body>
This is my test JSP page. <br>
<%
HashMap map=*new* HashMap();
ArrayList valueList=*new* ArrayList();
valueList.add("value");
map.put(*new* Integer(1),valueList);
ArrayList list=*new* ArrayList();
list.add(*new* Integer(1));
request.setAttribute("keys",list);
request.setAttribute("testMap",map);
*if* (request.getAttribute("keys") != *null*)
{
HashMap myMap = (HashMap)request.getAttribute("testMap");
%>
<logic:iterate id="element" name="keys">
<%
Integer myElement = (Integer)element;
List myList = (List)myMap.get(myElement);
*if* (myList == *null* || myList.size() <= 1)
{
System.out.println("test!!!");
*continue*;
}
%>
</logic:iterate>
<%
}
%>
</body-->
When I put the code in the a jsp file(index.jsp), start the tomcat 5.x
server and access the page(index.jsp), the console prints the “test!!!”
endlessly. But if I excute the same code in tomcat 4.0.1,the “test!!!” only
prints one time.
So I try to find out the reason, and finally I find that it is the JSP
compiler that cause the problem. When I compare the java code generated by
the two compilers,I find the result of compiling the logic:iterator(struts)
is not the same.
In tomcat 4.0.1, it like this:
*code 1*
*do{*
*…….//omitted codes*
*if** (myList == **null** || myList.size() <= 1)***
*{***
* System.out.println(**"test!!!"**);***
* **continue**;***
*}***
*……//still omit*
* *
*} while (_jspx_th_logic_iterate_0.doAfterBody() ==
javax.servlet.jsp.tagext.BodyTag.EVAL_BODY_AGAIN);*
But in tomcat 5.x,it becomes:
*code 2*
*do{*
*…….//omitted codes*
*if** (myList == **null** || myList.size() <= 1)***
*{***
* System.out.println(**"test!!!"**);***
* **continue**;***
*}***
*……//still omit*
* *
*if (evalDoAfterBody != javax.servlet.jsp.tagext.BodyTag.EVAL_BODY_AGAIN)*
* break;*
*} while (true);*
In code 2,when the code is excuted the “*continue*” statement, it jumps to
the “*while(true)*”. Again, the “*continue*” is excuted, angain the “*
while(true)*”. So we encounters the Endless loop.
But in code 1, the problem is noe exist. You see, when the “*continue*”
statement is excuted, it jumps to the “*while
(_jspx_th_logic_iterate_0.doAfterBody() ==
javax.servlet.jsp.tagext.BodyTag.EVAL_BODY_AGAIN)*”. It then break the while
loop.
I test the code in tomcat 4.0.1, tomcat 4.1.40, tomcat 5.5.27, and tomcat
6.0.20. It seems that the code works normally only in tomcat 4.0.1.
Thank you for reading my letter.Looking forward to hearing from you.
Your sincerely, Ma Jun
