AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  simple persistence without databases          AppletTalk.com Forum Index -> Java and Databases View previous topic :: View next topic   Author Message slothbear Guest Posted: Tue Mar 08, 2005 7:52 pm    Post subject: simple persistence without databases I have a simple application that has been using standard serialization for the save format. I have a small user community; no one has complained about the save format breaking with each new version (because I change class structure). But ... it is kind of unprofessional and I would like to fix it. A "real" database looks like overkill. Some of the smaller options (M.A.O.S., db4o) look interesting, but they are still kind of heavy/complicated for my little program (which is currently 88K). My current plan is to save one big Map, which will contain an assortment of smaller Maps with simple types. That will get rid of the class structure dependency. Much of the data are already in Maps (of simple types), so the save/load code will not have to do much juggling of values. Does that sound like a reasonable plan, or has my searching/researching overlooked a more simple method? thanks! Back to top Manuel J. Goyenechea Guest Posted: Tue Mar 08, 2005 10:08 pm    Post subject: Re: simple persistence without databases You may want to take a look at Servertec Persistent Object Store (POS). www.servertec.com/products/pos/pos.html "slothbear" <farbot (AT) gmail (DOT) com> wrote Quote: I have a simple application that has been using standard serialization for the save format. I have a small user community; no one has complained about the save format breaking with each new version (because I change class structure). But ... it is kind of unprofessional and I would like to fix it. A "real" database looks like overkill. Some of the smaller options (M.A.O.S., db4o) look interesting, but they are still kind of heavy/complicated for my little program (which is currently 88K). My current plan is to save one big Map, which will contain an assortment of smaller Maps with simple types. That will get rid of the class structure dependency. Much of the data are already in Maps (of simple types), so the save/load code will not have to do much juggling of values. Does that sound like a reasonable plan, or has my searching/researching overlooked a more simple method? thanks! Back to top dar7yl Guest Posted: Tue Mar 08, 2005 10:45 pm    Post subject: Re: simple persistence without databases "slothbear" <farbot (AT) gmail (DOT) com> wrote Quote: I have a simple application that has been using standard serialization for the save format. I have a small user community; no one has complained about the save format breaking with each new version (because I change class structure). But ... it is kind of unprofessional and I would like to fix it. A "real" database looks like overkill. Some of the smaller options (M.A.O.S., db4o) look interesting, but they are still kind of heavy/complicated for my little program (which is currently 88K). It may seem like overkill now, but later, after you have used databases for a while, you will wonder how you got along without them. Using databases does involve a learning curve. You have to figure out SQL, jdbc, tables, columns, rowsets, user passwords and logins, prepared statements, and other complications. However, using a database can add a whole new dimension to your application. For instance, you appear to be saving the application's state in one "chunk" per user. With a relational database, that state can be saved over a number of tables/rows. Only the portions of the state that have been changed need be updated to the database. I personally use MySQL. It is easy to install and maintain, and is efficient in terms of computer resources used. It is fairly efficient for small datasets, and has good performance for very large databases. As an aside, I would discourage the use of serialization for external state storage for precisely the reasons you have given - it is hard to control revisioning. It is better to define an external storage format (with provision for future expansion) and explicitly code for that interface. (IMHO) regards, Dar7yl Back to top slothbear Guest Posted: Tue Mar 08, 2005 11:19 pm    Post subject: Re: simple persistence without databases Thanks for the thoughts. I have been learning MySQL, but had not thought to use it for this project so far (since it is a standalone application for each person that uses it). If I understand your idea of an external storage format -- that is approximately what I was proposing by serializing a Map of Maps and simple types -- although I suppose I could still get in trouble if the definition of Map ever changed. Back to top Robert Klemme Guest Posted: Wed Mar 09, 2005 1:50 pm    Post subject: Re: simple persistence without databases "slothbear" <farbot (AT) gmail (DOT) com> schrieb im Newsbeitrag news:1110311527.226614.104670 (AT) f14g2000cwb (DOT) googlegroups.com... Quote: I have a simple application that has been using standard serialization for the save format. I have a small user community; no one has complained about the save format breaking with each new version (because I change class structure). But ... it is kind of unprofessional and I would like to fix it. A "real" database looks like overkill. Some of the smaller options (M.A.O.S., db4o) look interesting, but they are still kind of heavy/complicated for my little program (which is currently 88K). My current plan is to save one big Map, which will contain an assortment of smaller Maps with simple types. That will get rid of the class structure dependency. Much of the data are already in Maps (of simple types), so the save/load code will not have to do much juggling of values. Does that sound like a reasonable plan, or has my searching/researching overlooked a more simple method? Yes, I think so. Please take a look at XML bean serialization. That way it's human readable (well, sort of) but more important so, you can load old configs with new classes. And as long as you just add members, you don't have to do anything to read the old config. I guess it becomes more complicate if you rename fields etc. http://java.sun.com/products/jfc/tsc/articles/persistence4/ http://java.sun.com/j2se/1.4.2/docs/api/java/beans/XMLEncoder.html http://java.sun.com/j2se/1.4.2/docs/api/java/beans/XMLDecoder.html Kind regards robert Back to top slothbear Guest Posted: Thu Mar 10, 2005 2:04 am    Post subject: Re: simple persistence without databases Thank you for the information about XML bean serialization. That looks very promising. I am finishing up the review of my data model, and am still open to other ideas and suggestions. <sb> Back to top ableofhighheart@gmail.com Guest Posted: Fri Mar 11, 2005 8:06 pm    Post subject: Re: simple persistence without databases You might also wanna try XSream for xml serialization. http://xstream.codehaus.org/ Doni Ocena Back to top slothbear Guest Posted: Sat Mar 12, 2005 5:07 am    Post subject: Re: simple persistence without databases Wowwee..... XStream may be even better for me than XML beans ... especially since my objects are not already coded as beans. I just experienced the advantage of a human-readable format with my brief test of XStream. Even though I used a small data set, I got over 600 lines of XML -- which did not seem right. A glance at the file showed many copies of my 40-color palette -- which I had forgotten to mark as static. thanks tons! Back to top frebe Guest Posted: Sat Mar 12, 2005 6:08 am    Post subject: Re: simple persistence without databases Hypersonic SQL (http://hsqldb.sourceforge.net) has a footprint of 260K. I think that can be considered as acceptable in your case. (Rememeber that java itself has a footprint > 10MB). Fredrik Bertilsson http://butler.sourceforge.net Back to top slothbear Guest Posted: Tue Mar 15, 2005 4:21 am    Post subject: Re: simple persistence without databases I would like to do some fairly complex queries as my application evolves ... and would like to offer query support to my users too. Since SQL is such a standard, I will definitely look into using Hypersonic SQL. The footprint is an interesting topic. Some of my customers use my product because they only have a dial-up connection, and 88K is easy to download. They are frequently non-Windows users, and already have Java as part of their OS. Another 260K should not break the bank though -- thanks for the suggestion. <sb> Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> Java and Databases All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.