I've recently written my first grails application.
The application is a "product" in that I'd like to build a single version of the application that can be deployed to multiple customers as a war file.
I need to be able to configure each application differently.
What is the "best practice" for deploying a grails application as a product.
I found this documentation after some searching on the grails site.
3.4 Externalized Configuration
The default configuration file Config.groovy in grails-app/conf is fine in the majority of cases, but there may be circumstances where you want to maintain the configuration in a file outside the main application structure. For example if you are deploying to a WAR some administrators prefer the configuration of the application to be externalized to avoid having to re-package the WAR due to a change of configuration.
In order to support deployment scenarios such as these the configuration can be externalized. To do so you need to point Grails at the locations of the configuration files Grails should be using by adding a grails.config.locations setting in Config.groovy:
grails.config.locations = [ "classpath:${appName}-config.properties",
"classpath:${appName}-config.groovy",
"file:${userHome}/.grails/${appName}-config.properties",
"file:${userHome}/.grails/${appName}-config.groovy"]
In the above example we're loading configuration files (both Java properties files and ConfigSlurper configurations) from different places on the classpath and files located in USER_HOME.
Ultimately all configuration files get merged into the config property of the GrailsApplication object and are hence obtainable from there.
See the section on External configuration at this link. I'm not sure if this will configure everything you need but it should be a start and will cover the basics such as data sources.
Related
I need a advice for design purpose my structure of the application is as follows.
I have three module designed in ZK framework as a separate war application (web application) e.g finance-module , general-ledger and cash-account , all are separate war files can be deploy on tomcat as a separate war files,
Now I want to have a seperate war ZK application that has index or home page and have menu and from that menu I can able to call these three module or war application.
-------------------------- Main module -------------
Menu : general-ledger link , cash-account-link ,finance-module
1) This 4th Main module also has feature to user login and change user preference , means can also have code e.g view module as well as spring service.
Now the question is that how to call other war files zul pages and even if v call how to manage from 4th module and also how to share session across the four war files or applications.
Thanks
Vikas
I have worked in a similar scenario and this worked well for us:
When you create separate war's it means that they are independently running in it's own web context inside tomcat. Usually when you want to share resources like datasources, transactionManagers, or any other kind of jee resource you need to configure them at the tomcat instance level and they will be available in the JNDI directory of the tomcat server and any web application can pull any of them to use it.
https://tomcat.apache.org/tomcat-8.0-doc/config/context.html
https://tomcat.apache.org/tomcat-8.0-doc/jndi-resources-howto.html
There are several jee resources than you can share in the tomcat server but if you need more flexibility and robustness you might need a full stack java enterprise application server like wildfly http://wildfly.org/news/2014/11/20/WildFly82-Final-Released/ or any other commercial like WebSphere, Oracle Weblogic, etc
Now, if you want to share java classes, zul's or any other file, you may want to package them in separate common jars and use them in any war as a dependency and then reference them through the classpath of the web application.To organize and maintenance this modular projects Maven and Gradle are very good tools you can use.
From ZK you can call any other url of the other war's as simple as
<a href="htt://myserver/account/home.zul" label="Account"/>
<a href="htt://myserver/finnance/home.zul" label="Finance"/>
To share the session what you need is to implement a Single Sign On (there are other implementations like oracle opensso), you can configure it directly in tomcat but be aware of this Sharing security context between few web applications .
Spring Securityhas an extraordinary support for this kind of escenario.
Eclipse's Web Tools Platform (WTP) allows you to configure Tomcat to "Server modules without publishing":
Web content will be served directly from the "WebContent" folder of the Dynamic Web Project. A customized context is used to make the project's dependencies available in the Web application's classloader.
In a 5 step process (just joking, you pick the # of steps), what happens technically and where are the files that Eclipse generates? I did notice that Eclipse generated a org.eclipse.jst.server.tomcat.runtime.70.loader.jar file in the Tomcat lib directory.
The idea is to serve a web application directly from the scattered directory structure of the development workspace, without packaging modules into JARs which then end up in WEB-INF/lib in a WAR.
The main benefits are:
You don't need to build archives.
When you change a resource in your workspace, the change is reflected in the running webapp without redeploying the webapp or restarting the server.
With Servlet 3.0, web resources may also be bundled in library JARs in META-INF/resources, so classes and resources may come from multiple workspace directories.
Tomcat 7.0 supports a VirtualWebappLoader and a VirtualDirContext to configure a web application based on a collection of scattered resource and class directories.
To serve your web app directly from your Eclipse workspace, WTP generates a suitable Tomcat configuration matching your project structure
in $WORKSPACE/.metadata/.plugins/org.eclipse.wst.server.core/tmp1/conf/server.xml
For some reason, WTP does not directly use the Tomcat loader and context implementations but has its own WtpDirContext and WtpWebappLoader which are slightly different but similar. (I believe this approach is older than the current solution in Tomcat. There is some special logic for TLD scanning - I'm not sure if this is still required with the latest Tomcat versions.) These helper classes are contained in the org.eclipse.jst.server.tomcat.runtime.70.loader.jar you noticed.
Without Serve modules without publishing, when you change a web resource in META-INF/resources in a library module, this change will not be directly visible in the running application after reloading the current page in the browser.
Hullo - issue is this:
I wrote a servlet in Eclipse which requires mysql-connector-java-5.1.22-bin.jar
To compile I need to add the jar via the project's "Java Build Path"
To deploy I need to add the jar to the project's "Deployment Assembly"
To run the servlet within eclipse I need to add the jar to the servlet's Run Configuration -> Classpath
It's not the end of the world re-re-repeating myself like this, but it does seem odd.
Given that Eclipse gets a lot of other stuff correct I'm guessing / hoping that maybe I'm overlooking some feature to avoid this silliness (I cannot imagine a scenario where you'd benefit from entering this in 3 different spots ... but maybe I'm being uncreative here ...).
Insights appreciated :-)
The only thing you need to do is to drop the jar in WebContent/WEB-INF/lib.
You are developing a Java Web project, so the traditional place to put the required libs (JAR files etc) is under /WEB-INF/lib. And you do it only once.
In Eclipse, when you create Dynamic Web Project the appropriate project structure is generated for you (this is a development structure). In this case you place your JAR files in ProjectName/WebContent/WEB-INF/lib folder. And this folder is *automatically included in the project's build path.
Considering the fact that it is a Java Web project (you said you use servlets) you have to deploy your web app to some Application Server, like GlassFish, JBoss, WebLogic, WebSphere etc, or more simple Web Container like Apache Tomcat. If you do this thru Eclipse, then again your web project is automatically deployed.
NB!
There may be some additional details related to using libraries.
For instance, when it comes to using database drivers (MySql, PostgreSQL, Oracle etc) Tomcat advises the following while configuring JNDI Datasource (quote):
Before you proceed, don't forget to copy the JDBC Driver's jar into
$CATALINA_HOME/lib
In your case (MySQL) see the example here: MySQL DBCP Example
Also see my answer related to Webapp configuration file organization convention.
Hope this will help you.
P.S. Here is a step-by-step example: How do I access MySQL from a web application?
I am developing a Java EE 6 bottom-up JAX-WS to expose an EJB3.1 stateless session bean. The web service in a WAR is failing to install on deployment because it references an external jar (or shared library) which one can assume is not loaded yet.
The common suggestion is to include the jars in the /lib folder, which does fix the issue, however the jars need to remain in this external shared library location and NOT in the ear file, because they amount to 30MB.
What are some techniques to get around this issue in a Websphere (WAS v.8) environment or any server environment.
Some suggestions I have found include:
1. define classpath in META-INF file.
2. define the resources in deployment.xml
3. alter class loading order
4. (from ibm) In the case where the jars are part of a Shared Library configured on WebSphere Application Server, then a User Library must be used to configure the project for development before generating the WebService.
However, I have been unsuccessful to find any help online in these areas. Is there another technique or does anyone know anything about accomplishing this? Thanks in advance.
EDIT: If I specify the libraries in the META-INF using class-path, they are loaded before extensions, shared libraries..etc, but they are still loaded after the WAR which is not good. Again, this isn't a runtime issue because the web services are created at deployment on the fly.
I submitted a ticket to IBM. The libraries referenced by the web service are needed during deployment and must be bundled into the Ear in some fashion. I threw them in the web-inf/lib folder. However, if the referenced libraries then depend on additional libraries, these can be placed in the Shared Libraries. Seems odd to me too, but let's all just admit "shared libraries" are a hack anyways.
If you still have issues, just make sure your class loading is set to parent_last.
I have a Java web app that offloads some environment specific settings (Hibernate configurations, required directory paths, etc.) in a properties file that is ultimately packaged in the deployed WAR. If I wish to distribute this web app, what's the best way to handle the mangement of these settings? It's not feasible to ask the user to open up the WAR, update the properties file, repackage the WAR, and then deploy. I was thinking of either creating an installer (e.g. NSIS, WiX) that asks for the properties, writes them in the WAR, and then asks for the deployment location for the WAR. The other option is to have the properties file external to the WAR, and based on convention the web app will know where to read the file. What's the best practice in this case?
Some projects that require this sort of configuration, and face this issue, use the approach of building the projects (and the .war) on the server where it will be deployed.
So instead of:
Copy a pre-packaged .war file to a meaningful location
You get:
Check source code out of SCM (Subversion, CVS, etc.)
Configure to taste
Build the project (automated with Maven or Ant)
Deploy the project (also typically automated using Maven or Ant)
From here you can get fancy by checking each server's configuration files into SCM as well. This approach allows you to version & audit configuration changes.
I was also facing the same problem in the project. The developer before me had done crude fix for the solution which was adding all the required configuration in the hibernate.hbm.cfg.xml file and commenting them. The required configurations were uncommented as per the need. There is a better solution to problem however.
Use a configuration folder schema
Using configuration Parameter Reader
Use of ConfigurationReader component
Source : http://www.javaworld.com/javaworld/jw-11-2004/jw-1108-config.html