Unable to determine what is the best way to connect to mysql database in struts..
We can always use DriverManger and Class.forName() to connect.
DataSource interface - but this has problems I am getting compliation error for
DataSource dataSource = (DataSource)context.getAttribute(Globals.DATA_SOURCE_KEY);
or when Action.Data_SOURCE_KEY is used. when searched I found that these variables are depricated.
How can I use connection pooling in struts?What is best place to place url,username,pass for database?DO i still have to use datasource configuration in same way in struts-config? Then why was this facility depricated?
Too many queastions but I cannot find a definite source to learn struts.
Struts doc can be but then revisions and backword compatibility are the issues which a learner cannot get easily... Pls suggest a good source to learn struts2.
Struts is an MVC framework, not a database access framework. You should use some sort tool for your Data Access Layer. Spring makes it really easy to manage connections, transactions, and the sort, and integrates well with ORM tools like Hibernate or the JPA implementation.
Where Struts fits in in this is that it will manage the request, delegate to an action, which in turn will invoke a service that uses your data access layer. You could put your DAL in your actions, but I wouldn't -- I would put them in a service.
Struts is a framework having the MVC approach. It makes you to create application in an efficient way. Connection between database is somewhat risk compare to someother connection.
Related
I am creating a web interface for an old piece of software running on an Access 2000 DB. There is no support for the Entity Framework Model for Access. Is there a way of making a connection to work with breeze?
Try to use Ado.net, there is no support from breeze to Access
http://www.c-sharpcorner.com/uploadfile/mimrantaj/connect-to-access-database-in-C-Sharp-and-ado-net/
I like your idea of putting EF in front of SQL Server express. But if that doesn't work out, your only serious impediment is finding a way to expose access to your Access (chuckle) over HTTP.
Have you got that figured out? Maybe Web API? Because once you figure that out, it will be "easy".
You do NOT need EF for Breeze clients. EF is a convenient technology for many .NET developers ... but not everyone. All Breeze really cares about is the data.
You will need to get some some metadata describing your service model (meaning whatever you expose as client-facing objects in your HTTP service). You can produce that in many ways. EF is one way (it's easy) but you can also do it in JavaScript.
The task is to create several JSPs, in which the user would be able to interact by inputting information, which would be saved on a database server, so the info can be called up later.
I'm not sure if this question is constructive enough or not, but I have no idea how to even start. I know what each one of the components means, but that's about it. I have no idea how the whole process works and I don't know what's it called, so I can't even search for it properly.
Could anyone briefly describe the process from start to finish how this system would work and what should be my first concern? I'm more interested in the JSP hosting (would Tomcat be a better choice, or is Geronimo much better in my case) and the connection of JSP to the database.
You need several components and layers for an application like that, so the first thing to do is select your technology stack so you don't reinvent the wheel and adopt best practices that your frameworks include. My choice, is Spring Framework.
Your JSP's represent the View Layer of your app. You can use JavaScript/AJAX to embelish your forms and sent data to your server.
The data that the user enters in the form is received and processed by the Controller Layer. Spring MVC has some neat collection of controllers for you to use. Once the data es ready, you can pass it to the Service Layer to execute Business Logic.
The Service Layer contains Business Logic rules. Spring Framework let this Layer to be simple POJO's, and to apply Transactional logic if you wish. It's highly probable that Service Layer requires to persist some data in the Database, so it invokes the DAO layer.
The classes in DAO layer have the responsability of storing data in the database. You can use several frameworks for this, and Spring supports many of them. Also, Spring includes some inherent JDBC support with templates included.
With that you can start your project. It should run with no problems in Tomcat, Geronimo or any Java EE Container
I am designing a simple C# WCF service using ASP.NET 4.0 and hosted on IIS7, which will be used by .NET and Java web applications and desktop applications to extract data stored in various databases (both local and remote). I am starting to learn how to use VS2010 and WCF after working for a few years on VS2005 and asp.net web services, so am somewhat of a noob to WCF but know a bit about web services and Visual Studio.
Does anyone have opinions on what the best approach would be in terms of project/class/file setup in Visual Studio 2010 to do this, seeing as how I want to maximize code re-use and minimize development time yet still have the ability to connect to the different databases? I have a WCF Service Application project for the service, and have generated a WCF Client to use for testing using svcutil.exe, but now I'm at the point where I need to start writing database access layer code (or "model" code for MVC if that's the design route I need to go down).
Any help appreciated, thanks!
Each of the databases will have their set of nuisances while integration. The first thing you need to start with would be to design your model in more of OO (Object Oriented) fashion than relation DB way. Once such a model is created, you need to implement mapper layer/classes that would map data from a relational form to a OO format. Then for each DB you need to write some data access code. The amount of code you write for data access may well depend upon the tools\technologies you use. You could look into Entity Framework or NHibernate or other such ORMs to decrease the code required to access data. But keep in mind these ORM mappers may require their own set of tweaks to work well with MySQL, Oracle, SQL Server.
In my application, the entity database schema is created after application deployment based on inputs captured from end user, using a tool. I cannot use Entity Framework in this situation, since modeling is not possible without development environment (Visual Studio). The 'Code First' approach is also ruled out since it would require code generation which may lead to needless complexity.
Anyhow I need a Data Access Layer. I am therefore planning to introduce Data Access Application Block (DAAB) into my solution. Using SQL Management Objects (SMO) I can carry out the DDLs and for Data access I will use DAAB.
Now here is my confusion. Can I use LINQ for SQL technology on top of DAAB? I want DAAB to abstract all data access related complexities and then use LINQ to query. I also have a situation where I need to expose entity data through RESTful interface (read as OData). Would I be able to expose my data using WCF Data Services via DAAB?
LINQ is not supported in DAAB. DAAB is based on the good old DataSet and DataReader approach. This post has much more detailed answer with respect to role of DAAB.
LINQ support in Enterprise Library Data Access Application Block
I don't yet fully understand your scenario. If your database schema is created after deployment, then hows your front end application being developed against (as there wont' be any schema, if I get your question right).
If the schema is created after deployment what functionality is in your deployed application. Are you creating user interfaces on the fly using the dynamic schema that end user modelled?
Please do correct my understanding also good if you can give in some more info about your scenario.
i was asked to do a book manager at university with hibernate and mysql. I have a simple question. If i choose to do a web application, grails already uses hibernate. GORM runns over hibernate. so to use mysql i only need to configure jdbc grails drivers and that's it?
i mean, "for the project you must use hibernate and mysql" - this are the requirements. So can i do that way?
thanks in advance,
JM
Yes, of course you can.
You'll need to get the MySQL JDBC driver from this location.
Grails? When you're new to programming? Whose idea was this?
Personally, I think that taking on all these unknowns is risky for someone who's "new to programming." Do you know anything about SQL or JDBC? Have you ever written a web project before? This could be difficult.
I don't know how to be more specific. Download the JDBC JAR from the link I gave you.
I'd recommend that you start with a JDBC tutorial first. Hibernate is not for you - yet.
Hibernate is an object-relational mapping tool (ORM). It's a technology that lets you associate information in relational database tables to objects in your middle tier. So if you have a PERSON table with columns id, first, and last Hibernate will let you associate those data with the private data members in your Person Java class.
That sounds easy, but it gets complicated quickly. Your relational and object models might have one-to-many and many-to-many relationships; Hibernate can help with those. Lazy loading, caching, etc. can be managed by Hibernate.
But it comes at a cost. And it can be difficult if you aren't familiar with it.
If you have a deadline, I'd recommend creating a Java POJO interface for your persistence classes and doing the first implementation using JDBC. If you want to swap it out for Hibernate later on you can do it without affecting clients, but you'll have a chance of making progress without Hibernate that way.