Re: Use of Vectors in JSP
Amit - java.util.HashMap allows null values whereas java.util.Hashtable does not allow null values. Deepak - JOT Servlets provides an Iterator bean that wraps a JDBC ResultSet for repeating rows of output on a web page. You can work directly with the ResultSet methods instead of transferring the values to another Collection like a Vector. -- Paul Copeland, JOT Object Technologies - http://www.jotobjects.com -- Date:Tue, 19 Nov 2002 03:50:31 -0600 From:Amit Wadhwa [EMAIL PROTECTED] Subject: Re: Use of Vectors in JSP i use a 2-dimensional array. i have a bean to which i send the query, the query is processed by the bean, stored in an 2-d array, and the array is stored as an object in a hashtable which is returned to the calling jsp/servlet where i iterate thru the 2-d array and get the results. its working pretty ok but u have tro b careful about null pointer exceptions. anyone with any suggestions on this? * Amit Wadhwa Technical Support Representative, Dell International Services, Bangalore * -Original Message- From: Hans Bergsten [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 19, 2002 10:47 AM To: [EMAIL PROTECTED] Subject: Re: Use of Vectors in JSP Deepak wrote: Hi all Would you recommend the use of Vectors in jsp pages to hold the query results from a database? Is it ok then performance wise to iterate over the vector and display the items in the jsp page? For example, a method in a javabean executes a jdbc statement that returns some recordsets. These recordsets are added to a Vector and the Vector is returned by the method. In my jsp page I get the Vector with recordsets from the bean method. Then I iterate over the Vector to display its items in a html table. Is this a good way of doing things? If not can anyone suggest a better way? The methods in Vector are synchronized, so a List or an array is a slightly more efficient approach. But I would suggest that you look at JSTL instead. It's sql:query action exposes the query result as a type called a Result. From a Result, you can get an array of arrays where the first dimension represents rows and the second the column value, or as an array of Maps where each Map represents a row, with keys matching column names. Even if you access the database in servlet code (for instance), you can use utility methods to convert a JDBC ResultSet to a JSTL Result. For more info, see: http://java.sun.com/products/jsp/jstl/ Hans === To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
JSP for VoiceXML
How to set content type for VoiceXML files .vxml Anyone know this? Thanks ==To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
Re: Use of Vectors in JSP
hi Paul, i store the whole 2-d array in the hashtable whose values maybe null sometimes, but the whole array will never be null , and thats all i store as an object in the hashtable. when i said nullpointer exceptions, i meant the retrieval of data from the array whose one or more elements may be null. regards, amit -Original Message- From: Paul Copeland [mailto:[EMAIL PROTECTED]] Sent: Monday, November 25, 2002 9:07 AM To: [EMAIL PROTECTED] Subject: Re: Use of Vectors in JSP Amit - java.util.HashMap allows null values whereas java.util.Hashtable does not allow null values. Deepak - JOT Servlets provides an Iterator bean that wraps a JDBC ResultSet for repeating rows of output on a web page. You can work directly with the ResultSet methods instead of transferring the values to another Collection like a Vector. -- Paul Copeland, JOT Object Technologies - http://www.jotobjects.com -- Date:Tue, 19 Nov 2002 03:50:31 -0600 From:Amit Wadhwa [EMAIL PROTECTED] Subject: Re: Use of Vectors in JSP i use a 2-dimensional array. i have a bean to which i send the query, the query is processed by the bean, stored in an 2-d array, and the array is stored as an object in a hashtable which is returned to the calling jsp/servlet where i iterate thru the 2-d array and get the results. its working pretty ok but u have tro b careful about null pointer exceptions. anyone with any suggestions on this? * Amit Wadhwa Technical Support Representative, Dell International Services, Bangalore * -Original Message- From: Hans Bergsten [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 19, 2002 10:47 AM To: [EMAIL PROTECTED] Subject: Re: Use of Vectors in JSP Deepak wrote: Hi all Would you recommend the use of Vectors in jsp pages to hold the query results from a database? Is it ok then performance wise to iterate over the vector and display the items in the jsp page? For example, a method in a javabean executes a jdbc statement that returns some recordsets. These recordsets are added to a Vector and the Vector is returned by the method. In my jsp page I get the Vector with recordsets from the bean method. Then I iterate over the Vector to display its items in a html table. Is this a good way of doing things? If not can anyone suggest a better way? The methods in Vector are synchronized, so a List or an array is a slightly more efficient approach. But I would suggest that you look at JSTL instead. It's sql:query action exposes the query result as a type called a Result. From a Result, you can get an array of arrays where the first dimension represents rows and the second the column value, or as an array of Maps where each Map represents a row, with keys matching column names. Even if you access the database in servlet code (for instance), you can use utility methods to convert a JDBC ResultSet to a JSTL Result. For more info, see: http://java.sun.com/products/jsp/jstl/ Hans === To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com === To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
[no subject]
Hi, i want to know the differences b/w legacy classes and java2 collection API..what are the advantages of collection API over legacy classes..why sun has brought collections API.. give me details on this.. thanx in advance ==To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
[no subject]
http://www.javaworld.com/javaworld/jw-11-2002/jw-1101-collections.html -Original Message- From: Dinesh [mailto:[EMAIL PROTECTED]] Sent: Monday, March 25, 2002 2:14 PM To: [EMAIL PROTECTED] Subject: Hi, i want to know the differences b/w legacy classes and java2 collection API..what are the advantages of collection API over legacy classes..why sun has brought collections API.. give me details on this.. thanx in advance == To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com Disclaimer: This e-mail message along with any attachments is intended only for the addressee and may contain confidential and privileged information of GTL Limited. If the reader of this message is not the intended recipient, you are notified that any dissemination, distribution or copy of this communication is strictly prohibited. If you have received this message by error, please notify us immediately, return the original mail to the sender and delete the message from your system. === To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
Re: Hashtable / HashMap Problem.
use a TreeMap if you want the entries to come out sorted. -Original Message- From: Lakshmeenarayana G G [SMTP:[EMAIL PROTECTED]] Sent: 23 November 2002 07:27 To: [EMAIL PROTECTED] Subject: Re: Hashtable / HashMap Problem. Well guys... I got so confused with all these Collection API.. At last I sorted the values by using... ArrayList alist = new ArrayList(hashmap.values()); Collections.sort(alist); Then with the original map, I am looping through and getting the keys for the sorted values and in the loop I am feeding it to two Object Arrays. One for the Key and one for the Value. Now the two Object Arrays are having the sorted key values. I know this is not efficient way of implementing this solution. But why SUN has not given the hashmap.sortOnKeys() ?? Ok if hashMap takes the null values.. then at least they could have given hashtable.sortOnKeys()...??!!! thanks again for your time. Cheers.. L G Goundalkar. -Original Message- From: A mailing list about Java Server Pages specification and reference [mailto:[EMAIL PROTECTED]]On Behalf Of Amit Ghaste Sent: Saturday, November 23, 2002 1:46 AM To: [EMAIL PROTECTED] Subject: FW: Hashtable / HashMap Problem. I wonder why my reply went to the user and not to the list... anyways sorry to send it to uy directly but u can use java.util.LinkedHashMap as shown below Regards Amit -Original Message- From: Amit Ghaste [mailto:[EMAIL PROTECTED]] Sent: Friday, November 22, 2002 12:32 AM To: [EMAIL PROTECTED] Subject: RE: Hashtable / HashMap Problem. internally the hashtable stores object refrences according to hashcodes, if u get an enumeration of the stored values or keys, the order is not predictible its the same result with a iterator since hashmap is similar to hashtable (except that its meathods are not synched) it will give u the same result to preserve order use the LinkedHashMap... this preserves the order when u retrive it thro the keyset iterator but its meathods are not synchronized... so if u are doing multi threaded operation on shared data u need to synch it get more info from the api if that helps Amit -Original Message- From: A mailing list about Java Server Pages specification and reference [mailto:[EMAIL PROTECTED]]On Behalf Of Lakshmeenarayana G G Sent: Thursday, November 21, 2002 8:51 PM To: [EMAIL PROTECTED] Subject: Hashtable / HashMap Problem. Hi, I am using Hashtable or HashMap to keep Key-Value pair of elements. But When I add them, The Hashtable or HashMap gets sorted depending on the keys. I want to retain the order in which I have added the key-value pair. Is there anyway to do it with Hashtable or HashMap ? Or Can I use any other Collection type which will have the mapping of key-value which is not sorted other than two dimensional Array. Thanks for the time. Lakshmeenarayana G G CLI Division - SysArris Software Bangalore - India Tel. No. +91-80-665 4965, 665 5052, 664 2690 Xtn-240 Fax No. +91-80-665 0374, 655 4285 http://www.sysarris.com/ == = To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com == = To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com == = To unsubscribe: mailto [EMAIL PROTECTED] with body: signoff JSP-INTEREST. For digest: mailto [EMAIL PROTECTED] with body: set JSP-INTEREST DIGEST. Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com -- It is the strict policy of Truworths that its e-mail facility and all e-mail communications emanating therefrom, should be utilised for business purposes only and should conform to high professional and business standards. Truworths has stipulated certain regulations in terms whereof strict guidelines relating to the use and content of e-mail communications are laid down. The use of the Truworths e-mail facility is not
