I've read some articles on the Internet that this is not possible. To communicate own SQL database that is located on other server from GWT application. Jetty doesn't allow it.
I found a way how to perform it but it's not very cosy. I have client and server part inside GWT. The server has to communicate with MySQL database on localhost. So I've written an ant script to build a war that I can launch on Apache Tomcat server. It works perfectly there but I'm not able to debug the code effectively.
Do you have some advices how to perform this task? I was thinking of writing the clienty only in GWT and find some waz how to communicate my own server written outside the GWT. I've found Apache Thrift for GWT but this edited library of thrift seem not to work properly.
Thank you very much for your answers:)
It is possible to communicate with a database from a GWT application. The client side has to call the methods of the server via GWT-RPC, which can communicate with any database.
Maybe Jetty does not support it (have not tested it personally) but you can develop your web application using Apache too. There you can access the database the same way as from any web application:
You will need the mysql-connector-java-5.1.20-bin.jar file (downloadable from: http://dev.mysql.com/downloads/connector/j/ ), and restart the server added to the $CATALINA_HOME/common/lib directory.
OR added to the WEB-INF/lib folder of your web application.
You can find tutorials online of how to develop an application using Tomcat instead of Jetty. For example: https://wiki.auckland.ac.nz/display/BeSTGRID/Deploying+GWT+to+Tomcat+in+Eclipse
Reshi, stop and think about how applications really work. Nobody provides web pages with javascript to read/write databases, that would be crazy and unsecure. Servers are always in themiddle of all communication in this case. You need to create services that run inside your server, one of these services will be a database layer.
Javascript cant create network connections and read/write binary data, thus it would be insane to attempt to get the gwt compiler to compile any jdbc drvier and more.
Jetty does NOT stop us from connecting to a database. All you have to do is to follow the MVP model way. Although MVP is better bet against all hurdles, at a minimal point, you would have to try not having SQL code on the client package.
Related
Hi I'm sorry for the naivety of this problem but I need some guidance as I have confused myself greatly.
I have been tasked with creating a database(mysql) and creating a web interface for i to be interacted with. I have experience with web design and database development. Previously I have used java to interact with a DB and was hoping I could use JSP for the web interface. This is where my problem is, how I would I deploy/host this website?
I have 2 theories which are misguided:
(A). Use a cms which has a web server for me to place the jsps in?
or
(B). Use a domian/web hosting site that has a server for me to place the jsps in?
I'm totally lost and any guidance would be greatly appreciated.
Simple answer is you will require a Java Application Server to host your JSPs.
You can use Apache Tomcat, GlassFish, or some other application server to do this.
You will also need a database e.g MySQL running on your host or some other host accessible by the machine running the Java application server.
You can choose to host all of this locally or farm it out to a web host provider depending on your resources.
A CMS seems like overkill. See this link for a description of CMS and its functionality. I don't believe this is what you are looking.
I don't know exactly what you're looking for, but I think you need (B)
You need a MySQL instance running your database and a servlet container (e.g. Tomcat) to host your JSPs.
Running a CMS which is just used to use the DB that it works with is a little bit heavy for that usecase.
As suggested by Mr #cmd , yes there is no need to go for an outsourced server just to host your website, unless you need it to be visible to the world.
Else for your testing purpose, you can use Any of the Apache Tomcat, Glassfish servers for hosting the applications designed in JSP or in other web interface language.
And Inside of the JSP coding itself you may write the interaction coding with your database.
your database also can be installed in the same server.
And actually instead of a server, you may even use your PC to install the Apache Tomcat and the database and start using it.
I have an existing Java application running on a linux box that monitors the state of relays and network information. This is a stand-alone device currently.
What I would like to further develop is a web server for the device to remotely monitor, configure, and control the device via an Ethernet connection. To achieve this, I need some way to interface between the web server, which could be configured as enabled/disabled, and the master device, which is always running.
Is there a good way to do this? I have looked at apache w/ tomcat and similar web servers but not sure if this is what I need. The key here is that the web server needs to be able to access the existing java application without interfering with its always running services.
You either develop a webapp, use your Java application's API inside the webapp, and deploy this webapp inside a web container. Or you can do the reverse and embed a web server inside your application (see here for documentation to embed Jetty).
If you want to keep the webapp and the original application in two separate JVMs, you'll need some wey to communicate between both, like sockets, RMI, or even files, but it will be more complex.
You might want to take a look at JMX http://docs.oracle.com/javase/tutorial/jmx/overview/index.html
I want to run a standalone java application on a remote server. It would not be accessible to clients, but would do background calculations and interact with a database and Secure Socket connection to a third party site. It would also interact with a php site.
Do I have to deploy this with JSP, or can I write a standalone application? If so, how would I deploy a standalone java application (jar file) on a remote server? I understand that I must have them install a jvm on the server (not a problem) but then how would I deploy it (if possible). Would I start it with a command line?
I know I have much to learn, but I am not sure how I would access the command line on a remote server. Through the cPanel?
Thanks.
First of all, you'll want to set up some firewall rules to allow access to that server. I'm hoping that you don't expose that server naked to the Internet.
If all you need is database access exposed on the Internet, I don't see why it can't be a secured web app deployed on a servlet/JSP engine and accessed via a web server. You can leverage basic auth for security, JDBC access to the database from the server, and servlets as controllers to accept requests in a nice REST API.
It'll save you the complications of sockets and inventing your own protocol (use HTTP), starting and stopping the application (now it's just a web server/servlet engine), and deployment (send a WAR file).
Does it really must be a 'standalone' application? I think that in your case the best match would be to use Spring container to load your application within some server (tomcat?) and expose services via standard controllers - with Spring you only have to add some annotations on services methods actually.
Then, your php site can interact with these controllers using for example ajax requests.
If your application is written already, you can easily transform it to run within Spring container. It's very non-invasive and promotes usage of POJOs.
I've made a Google Web Application Project in Eclipse and am now running into problems as I need to use from a server side point of view, with Hibernate with MySQL. I've just been told that Google Web Application projects can't run Hibernate connections to MySQL as they're deployed projects.
What's the best way for me to migrate this project somehow so it runs on say Glassfish and just uses GWT for the client side technologies that can then use Hibernate and MySQL, rather than actually being deployed?
Thanks,
David
You cannot access database from client-side directly.
GWT translates your client-side java code into Javascript which runs in browser; there is no way to directly access JDBC.
You will have to employ server-side which will handle your DB persistence. Your client can communicate via GWT-RPC, JSON, XML, or any other protocol - but the database connection part will always reside on server.
Note that the server part does not need to be in Java - it can use PHP or any other technology, as long as it understands the javascript generated out of your app.
I have just became a partner of a company that has a site developed in JAVA. As part of the agreement they allow me to create a section on their site (so I can take benefit of their traffic), but the development of this section needs to be as less intrusive as possible.
So ideally I would like to implement an independant web application in JAVA (with same layout) with a separate database that runs in the same application server. And in the application server to make a mapping like this:
All the traffic that comes to www.domain.com/MY_FOLDER
its served by my web application, all the rest should be served by my partners site.
I have no experience in JAVA but I found that in php this can be done, so I was wondering if it can be done also in JAVA.
About the application server I dont know yet which one they are using but I guess that are using "resing server" (by caucho: http://www.caucho.com/).
I would really appreciate if you can give me any ideas of how I can achieve this.
Thanks in advance,
Juan
Only one application can listen at a given socket at one time, so you need to have the existing server forward "your" requests to your web application, if it is not Java capable in itself.
The way to do that is not standardized so you will have to talk to the server administrator.
The easiest way to start from scratch with a Java Web Application is in the Netbeans bundle with Glassfish.