Hello vaijayanthi !!
see the comments i made ....
Hope that helps
>From: Vaijayanthi Kolli <[EMAIL PROTECTED]>
>Reply-To: "A mailing list for discussion about Sun Microsystem's Java
> Servlet API Technology." <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: Re: ArrayIndexOutOfBoundsException
>Date: Thu, 18 May 2000 15:34:43 PDT
>
>Hi Ajai,
> Here is the code:
>the declaration part:
> private int limit=2;
> private int users=0;
> private Vector db_v;
> private Vector db_status;
> private int i;
>The code in the doPost method:
> users++;
> if(users>limit)
> {
> if(!addconnection())
> {
> System.err.println("Failed to connect to the
>database");
> return;
> }
> }
>
> boolean found=false;
> i=0;
> String val=" ";
> while(!found)
> {
> val=(String)db_status.elementAt(i);<---(1)
> if(val.equals("0"))<------if this isnt true in the first
>two runs ...the i value keeps on incrementing ...say the loop runs 5 times
>with out this being true .....
> {
> found=true;
> }
> else
> {
> i++;------------>here the i value is 5
> }
> }
> dbcon=(Connection)db_v.elementAt(i);------->throws an out of
>bound exception bcoz u have only 2 elements in ur bd_v vector.make sure the
>i value never increments above the number of elements in the vector ..The
>same exception is possible at (1) too for the same reason ...Also i dont
>see the code where u are adding elements to the db_v vector i assume that u
>are doing that....
> db_status.setElementAt("1",i);
>
>
>addconnection() is a public method which adds a new connection to the db_v
>vector and increments limit.
> All this is from the Wrox server programming book.
> Thanks.
>Vaijayanthi.
>
>
>>From: ajaikumar peddapanga <[EMAIL PROTECTED]>
>>Reply-To: "A mailing list for discussion about Sun Microsystem's Java
>> Servlet API Technology." <[EMAIL PROTECTED]>
>>To: [EMAIL PROTECTED]
>>Subject: Re: ArrayIndexOutOfBoundsException
>>Date: Thu, 18 May 2000 22:15:41 GMT
>>
>>send me that part of code probably u messed up with the >= ...
>>
>>
>>>From: Vaijayanthi Kolli <[EMAIL PROTECTED]>
>>>Reply-To: "A mailing list for discussion about Sun Microsystem's Java
>>> Servlet API Technology." <[EMAIL PROTECTED]>
>>>To: [EMAIL PROTECTED]
>>>Subject: ArrayIndexOutOfBoundsException
>>>Date: Thu, 18 May 2000 15:06:18 PDT
>>>
>>>Hi everybody,
>>> I am developing a website involving sevlets and an access
>>>database.The UI is created using HTML.
>>> I am implementing Connection Pooling in that.
>>> I store a certain no. of connections(in a var. limit) in a vector and
>>>keep
>>>track of the number of users(in a var. users).Once the number of users
>>>exceeds the limit(users>limit)I increase the limit by adding one more
>>>connection to the vector.
>>> I have set the initial value for limit as 2 and that of users as 0.
>>> When I try to access the servlet from two browsers simultaneously,and
>>>the
>>>value for users is 2,I get the following error:
>>>
>>>Error: 500
>>>
>>>Internal Servlet Error:
>>>
>>>java.lang.ArrayIndexOutOfBoundsException: 2 >= 2
>>> at java.util.Vector.elementAt(Compiled Code)
>>> at db1servlet.doPost(Compiled Code)
>>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:747)
>>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:840)
>>> at
>>>com.sun.web.core.ServletWrapper.handleRequest(ServletWrapper.java:140)
>>> at
>>>com.sun.web.core.InvokerServlet.service(InvokerServlet.java:169)
>>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:840)
>>> at
>>>com.sun.web.core.ServletWrapper.handleRequest(ServletWrapper.java:140)
>>> at com.sun.web.core.Context.handleRequest(Context.java:375)
>>> at com.sun.web.server.ConnectionHandler.run(Compiled Code)
>>>
>>> Can anybody tell me what is causing this problem?
>>>Secondly,what is the default capacity of a vector?
>>>
>>>Thanks in advance.
>>>Vaijayanthi.
>>>
>>>
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>>
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>
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