Develop Reference

How do you modify values in java properties file

I have a config.properties file which contains configurable properties e.g. database connection details in a webapp deployed on tomcat. e.g.
local.driver: com.mysql.jdbc.Driver
local.username:myuser
local.password:mypass
dev.driver: com.mysql.jdbc.Driver
dev.username:mydevuser
dev.password:mydevpass
I can retrieve the values from config.properties using spring Environment object or #Value.
My question is how do you make Spring's environment object pick local properties when running on local and dev properties when running on dev? Also it doesn't sound right to save sensitive data e.g. production database connection
details in properties file which will float around in code base. So how do you add production detail when in production environment? Ideally I would want to change them as and when I like and not have to redeploy the app. Am I going the right direction?
Note - All the answers I have seen on SO discuss changing these properties within java code. I don't want to do that I want to be able to configure these values independent of the application code.
Thanks

You can have a look at spring profiles to load a specific file for a specific environment.
Alternatively, you can also parameterize the file from where the properties are loaded in the application context using a JNDI property or an environment property set in the container.
Example:
<context:property-placeholder ignore-unresolvable="true" location="${env.config.file:classpath*:META-INF/spring/profiles/dev/dev.properties}" />
The env.config.file can be set at the container level (say Tomcat) using -Denv.config.file= when starting it. By doing this, Spring automagically finds the property in the system props and replaces it. If you don't set it explicitly (for example, in dev where you might use some other container, such as jetty), it would use the given default value (in this example, dev.properties).
By putting the properties files outside the war / ear, they can be changed at will, and only the context needs to be restarted. Alternatively, you could look into re-loadable property placeholders. This also helps if you don't want passwords stored in the war in clear.
For encrypting information in the property files, if you're using Spring 3, you can also check: http://www.jasypt.org/spring3.html.

for picking env specific values you have couple of options
If you can create multiple properties file based on env then you can use Spring profile feature (i.e spring.profiles.active), this will allow to control properties file to loaded via JVM parameter.
If you still want to keep all the stuff in single fle then you can override PropertyPlaceholderConfigurer to take env details from JVM parameter or default to some value
On security question , one the approach is to store encrypted password in prop file.

Coherence config default override path

I've already spent more than 2 days trying to make this work without any result. The server is WebLogic 12c with embedded Coherence server. It is important to mention that I do not run Coherence in standalone mode, instead it starts automatically alongside the application server that has access to Coherence via JNDI context. I am trying to implement POF serialization approach using PortableObject interface to serialize certain objects I save in Coherence. I've also created the corresponding pof-config.xml registering the objects I'm planning to serialize. The only problem is: How do I add the override to the coherence class path?
According to http://docs.oracle.com/cd/E24290_01/coh.371/e22837/gs_config.htm#COHDG5014 I can use the following system property:
java -Dtangosol.pof.config=MyPOF.xml -cp COHERENCE_HOME;COHERENCE_HOME\lib\coherence.jar com.tangosol.net.DefaultCacheServer
The only problem here is that I have no idea which sh/cmd file to edit, since all edits I made to the files in Oracle_Home\coherence\bin\ had no effect.
Also the same article says that there is a way to confirm the pof-config override:
The output for a Coherence node indicates the location and name of the POF configuration deployment descriptors that are loaded at startup. The configuration messages are among the messages that display after the Coherence copyright text is emitted and are associated with the cache service that is configured to use POF. The output is especially helpful when developing and testing Coherence applications and solutions.
Loading POF configuration from resource "file:/D:/coherence/my-pof-config.xml"
But I couldn't find any of the mentioned lines in the logs produced by the server instance.
Any ideas?

Instead of editing files inside of your Oracle_Home, try the following inside of the weblogic admin console:
Login to admin console
Servers link -> Server Name
Click the Server Start tab
Edit the Arguments: text box and add in -Dtangosol.pof.config=MyPOF.xml
You can also change the classpath, Class Path: box, here if you need to
Every time your server starts it should have that property. If you are not using the nodemanager to start your server, you should do the following instead. Keep in mind this will change the properties for every server in your weblogic domain:
Navigate to your <domain home>/bin directory
Edit startWebLogic.sh/cmd
Edit the JAVA_OPTIONS= line and add in -Dtangosol.pof.config=MyPOF.xml
You can also change the classpath CLASSPATH= here if you need to

log4j log not working in Websphere when Class loader setting is parent first

I am having two problems. In my application we are using custom email functionality with javax.mail api. Mails are going fine with out any error when the class loader setting is kept as Parent First but custom logs are not getting generated with that class loader setting.
When I update the class loader to Parent Last then logs are getting generated but the custom email functionality is not working, its getting freezed at message.saveChanges(); line and server is throwing time out error.
I have mail.jar & log4j.jar included in the WEB-INF/lib of the application and the log4j.properties file is present in the classes folder
Could any one please let me know what is causing this issue and Is there a way to make both logging and email functionality work with a single class loader setting.
Thanks.

This most likely is caused because Log4J doesn't load the configuration file (log4j.xml or log4j.properties) that you think it does.
Add the log4j.debug=true system property, restart the server and watch the logs. The logs (in SystemOut.log or SystemErr.log) will tell you exactly which configuration file was loaded.

Your version of JavaMail must be fairly old since you are using the 'mail.jar'.
Upgrade the JavaMail included with websphere to 1.5.3 which contains the fix for Bug 6668 -skip unusable Store and Transport classes. From the bug report:
In complex class loading situations, it can be possible for there to be
multiple copies of the JavaMail classes. A Store or Transport defined
by one copy may be loaded by another copy, but it won't be usable because
they're in different ClassLoaders. In this case, JavaMail should skip
over the unusable class and try to load the class from another ClassLoader.
This can happen, for example, in GlassFish if the application includes the
JavaMail classes, the application class loader is configured to prefer
application classes over system classes, and the app server itself tries
to use JavaMail when running in the context of the application.
You need to then remove that old version of JavaMail from your WEB-INF/lib and if need be, place JavaMail 1.5.3 in WEB-INF/lib too. I've tested this fix for GlassFish so I'm assuming lots of other appservers suffer this same issue.
You can download the latest snapshot and official releases from the JavaMail reference implementation home page.

com.sun.appserv.connectors.internal.api.ConnectorRuntimeException: Invalid resource

I'm trying to figure out where is the definition of the above resources stored. My application does not have and never had such resource defined. So I'm actually sure this is some kind of server reference but the question is where such stuff could be defined. It looks for me like some kind of cached references existing somewhere on the server and used when the same names are tried.
People advice workarounds like creating resources manually or using java:app/ prefix.
However I'd like to go tot the bottom of the problem and resolve the source of the problem instead.
The contain entity manager config could be the first thing to check but where is it?
What config file should I examine, modify or remove.
Here is the beginning of the error message:
Severe: Exception while preparing the app : Invalid resource : jdbc/CustomerDEV1__nontx
com.sun.appserv.connectors.internal.api.ConnectorRuntimeException: Invalid resource : jdbc/CustomerDEV1__nontx

To get rid of it, you´ll need to remove the persistence.xml cached by the IDE. For example (using Netbeans 8 under Windows 8.1):
C:\Users\jMarcel\AppData\Local\NetBeans\Cache\8.0\index\s71\java\14\classes\META-INF\persistence.xml
Hint: in WindowsExplorer, set your directory to C:\Users\yourUser**AppData\Local\NetBeans** and perform a search for the persistence.xml file.

I hope you are not letting the server know what type of resource you are looking up in the JNDI tree and confusing it. You look for JDBC resource in within application. Please note that if you use java:app/ then it means
The java:app namespace is used to look up local enterprise beans packaged within the same application. That is, the enterprise bean is packaged within an EAR file containing multiple Java EE modules. JNDI addresses using the java:app namespace are of the following form:
You have to use java:comp/env/jdbc/CustomerDEV1__nontx for JDBC Datasource. java:comp/env/jdbc denotes it is a JDBC resource in the Java components environment

Why is Realm setting required in Server.xml and not web.xml

I am working on a Java application for a while. I primarily work on .NET Platform. Although I feel lot of concepts are common between these two platforms but there are few areas where I am finding some issues related to the configuration.
I am working on Authentication and Authorization and thought I would get something similar to Membership APIs of .NET in JAVA. Closest which I got was using j_security_check. I also got to know about JAAS but think it is little too deep for me to dive into.
I have created the user and role tables in the database and now I have to specify the JDBC Realm settings somewhere. I am using Tomcat 7.0. In most places, it's mentioned that I need to specify the realm setting in the server.xml.But wouldn't that apply to all web application deployed on that server since it would become a server level configuration ?.
On a site I even saw a developer mentioning about context.xml but again can't see a standard document that mention about using this XML file for setting JDBC realm
In.NET, We always put Membership settings at the web.config level and not Machine.config.
Totally Confused on this. Looking for some light on this.

Why is Realm setting required in Server.xml and not web.xml
This is not true, you can define it in your webapp as well, but then only in a servletcontainer-specific configuration file, such as /META-INF/context.xml in case of Tomcat. It cannot be definied in /WEB-INF/web.xml because it's specific to the standard Servlet API, not the servletcontainer implementation.
But wouldn't that apply to all web application deployed on that server since it would become a server level configuration ?.
That's correct. This is not recommended if you have no control over the server or if you don't want to publish the realm through other webapps.
On a site I even saw a developer mentioning about context.xml but again can't see a standard document that mention about using this XML file for setting JDBC realm
You can specify it in webapp's /META-INF/context.xml. See also Tomcat's own documentation on the <Context> element:
Defining a context
It is NOT recommended to place <Context> elements directly in the server.xml file. This is because it makes modifying the Context configuration more invasive since the main conf/server.xml file cannot be reloaded without restarting Tomcat.
Individual Context elements may be explicitly defined:
In an individual file at /META-INF/context.xml inside the application files. Optionally (based on the Host's copyXML attribute) this may be copied to $CATALINA_BASE/conf/[enginename]/[hostname]/ and renamed to application's base file name plus a ".xml" extension.
In individual files (with a ".xml" extension) in the $CATALINA_BASE/conf/[enginename]/[hostname]/ directory. The context path and version will be derived from the base name of the file (the file name less the .xml extension). This file will always take precedence over any context.xml file packaged in the web application's META-INF directory.
Inside a Host element in the main conf/server.xml.
(emphasis is not mine, it is already as such in Tomcat's documentation)