logic to call back end from java

Posted on 2008-09-30
Medium Priority
Last Modified: 2012-05-07
hi guys

I am trying to figure out a logic for my code scenario.

I have a search screen where user enters range of ids. I have to retrieve information for the range of ids.

for example: 1-100 (i am storing this in string array ids)
i am getting all the id individually and passing each id in my backend query

for(int i=0; i< ids.length ; i++)
from jsp--> call middle layer --> call backend and pass 1 to "select * from table where customer_id= 1"
from jsp--> call middle layer --> callbackend and pass 2 to "select * from table where customer_id= 2"
from jsp--> call middle layer --> callbackend and pass 3 to "select * from table where customer_id= 3"
call backend and pass 100 to "select * from table where customer_id= 100"



but the problem is the above approach is taking long time because in above case i am executing 100 queries
so if the range is 1-10000, 10000 queries are executed which takes a very long time.

Is there any other alternative to this.
One of the options is range search, something like
select * from table where customer_id between 1 and 10000
but i dont want to do that because i need to pass indivual ids in the middle layer and then pass each id
to the back end.

Any idea how i can run the above 100 queries and improve the performance.

thanks v much
Question by:jaggernat
  • 2
LVL 61

Accepted Solution

Kevin Cross earned 1000 total points
ID: 22610330
You could build a List<Integer> or int[] to hold the id values and make one call to the middle tier passing in your List/Array.  

You could then make one call to the backend to find those exact values or use your thought of range searching a return of all the customers with ids 1 --> 10000.  What you could do there is create a bean like Customer to hold each individual record and implement Comparable using the customer_id member as the comparison field.

You can use something like this for range searching lists: http://crossedlogic.blogspot.com/2008/09/range-searching-using-java.html.

LVL 23

Assisted Solution

Ajay-Singh earned 1000 total points
ID: 22611300
In this flow,

from jsp--> call middle layer --> call backend and pass 1 to "select * from table where customer_id= 1"

You can collect the ids, you want to pass, and pass it a array. So, the middle layer, you need
to make modification so as to add api to handle array input. Now, you have a choice to use in query
in the backend with the received ids.
LVL 61

Expert Comment

by:Kevin Cross
ID: 22611390
Thanks for confirming what I thought, Ajay.  Good to know I was on the right track.

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