log4j produces no output on specific Weblogic servers - log4j

We are distributing an application that is deployed as a bunch of WAR files in various WebLogic servers (9, 10 and 11) at various customers' sites. Those apps are using commons-logging and log4j. It works perfectly everywhere except at a specific site where no logs are generated from our app. That site is on 11g and has a bunch of other Oracle software installed (BPEL, OSB etc)
In our code, we use:
public class Foo {
private final static Log log = LogFactory.getLog(Foo.class);
public void bar () {
log.trace("bar called");
...
Since we want to let the customers adapt their logs configuration, we have a configuration folder in the server CLASSPATH:
CLASSPATH=/opt/app/domain_foo/foo_config/:....
In that folder, two files for logs, commons-logging.properties:
org.apache.commons.logging.Log org.apache.commons.logging.impl.Log4JLogger
And log4j.properties: (this is a simplified one that has the same issue, actual file contains 5 loggers with various parameters)
log4j.rootLogger=INFO, fileApp
# File appender
log4j.appender.fileApp=org.apache.log4j.RollingFileAppender
log4j.appender.fileApp.file=fooapp.log
log4j.appender.fileApp.maxFileSize=10240KB
log4j.appender.fileApp.maxBackupIndex=5
log4j.appender.fileApp.append=true
log4j.appender.fileApp.layout=org.apache.log4j.PatternLayout
log4j.appender.fileApp.layout.ConversionPattern=%d{dd/MM/yyyy HH:mm:ss,SSS} %-5p %-70.70C %m%n
log4j.logger.be.foo=DEBUG
The file fooapp.log is created (so it was able to find the properties file) but empty.
I tried to check the log settings in Weblogic but they seem to be the same on working and not working servers.
I copied the CLASSPATH to my server and it is still working fine.
I don't really know where to look anymore. Any ideas ?

It is a bit tricky but the answer is in the environment named: APPLICATIONS_DIRECTORY that should point to the path where APPLICATIONS_DIRECTORY/fooapp.log should be. You can get the directory location from System.getenv("APPLICATIONS_DIRECTORY");

Related

Blazor server app cannot download .msg files

I have a Blazor Server 6.0 app where I have links to download .msg files.
I have setup IIS to serve that mime-type trying both application/octet-stream and application/vnd.ms-outlook (and restarting IIS)
I have also tried to put in web.config the staticcontent tag like suggested here:
.msg file gives download error
And obviously in my program.cs I have app.UseStaticFiles();
I try to put the .msg in a non-blazor app and they work ok, so I think is not IIS related
So why I cannot download (or open automatically in outlook) this type of file, while other (docx, pdf, zip, etc.) are Ok ?
ASP.NET Core -- on the server side -- also needs to know about the files it has to serve. You can enable serving all unknown file types (I'd rather not include the relevant code as it is a major security risk), or you can add you own additional mappings like so:
var provider = new FileExtensionContentTypeProvider();
provider.Mappings[".msg"] = "application/vnd.ms-outlook";
// app.UseStaticFiles();
app.UseStaticFiles(new StaticFileOptions()
{
ContentTypeProvider = provider
});
More info in the official docs: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/static-files?view=aspnetcore-7.0#fileextensioncontenttypeprovider
Additionally, Blazor Server registers custom options for serving static files (like .server.js, which is different from just .js). It's not directly exposed as a public API to configure, but you can look at the source here as to what the AddServerSideBlazor extension method actually does. The solution there relies on you calling UseStaticFiles without explicitly specifying the options, so that it can retrieve the StaticFilesOptions instance from DI.
Armed with this knowledge, you can override an already configured options instance as follows:
builder.Services.PostConfigure<StaticFileOptions>(o =>
{
((FileExtensionContentTypeProvider)o.ContentTypeProvider).Mappings[".msg"] = "application/vnd.ms-outlook";
});
This configures the already initialized options instance registered in the DI (after all other configurations happened on it, thus PostConfigure).
Note that if you would for whatever reason decide to use a different IContentTypeProvider, the unsafe cast above would need to be revised as well.

Mule not honouring log4j2.component.properties or log4j2.system.properties

I've a mule application which needs to load log4j2.xml from different locations as per the environment shown below.
app1
dev --> /etc/dev/app1/log4j2.xml
sit --> /etc/sit/app1/log4j2.xml
. . .
prod --> /etc/prod/app1/log4j2.xml
I don't want to use spring bean loading as by the time this bean is loaded, Mule would have already initiated log context for this app1 with default configuration and writes few logs to it.
Within log4j functionality, there are log4j2.system.properties and log4j2.component.properties files. When either of them is added to classpath (src/main/resources) with log4j.configurationFile property in it, it is supposed to pick up this file during application startup itself.
Reference: Log4j System Properties
log4j.configurationFile=${config.path}/app1/log4j2.xml
config.path is defined in wrapper as system property and available to app1 holding the env path ("/etc/dev" if dev or "/etc/sit" if sit etc..)
However, both of these files are not picking up by Mule and resolving to default configuration.
Can someone please assist in making any of these files pick up by Mule during application startup itself?
After long research, we have to update mule_artifact.json with "logConfig" key to define the location of external log4j2.xml file in server relative to mule_home path.
The same path may not work in local but you can create "mklink" to resemble server path in local.
I've tested successfully both.

ClassLoader - Loading and saving data

Hopefully someone can help me with this.
It is my understanding that using a ClassLoader is the most reliable way to load in content.
public class Pipeline{
public static URL getResource(String filename) {
return ClassLoader.getSystemResource(filename);
}
public static InputStream getResourceAsStream(String filename) {
return ClassLoader.getSystemResourceAsStream(filename);
}
}
If you had a file at "[jar bundle]/resources/abc.png" ..You would load it by:
URL url = Pipeline.getResource("resources/abc.png");
Loading is simple.
Saving is what's getting me.
I have a program that collects data while running, saves that data on exit, and then loads the data back in next time and keeps adding to it.
Easiest solution I think would be to save back into the jar bundle so that ClassLoader can get at them. Is this even possible? Or recommended?
I don't mind having my resources outside of the jar, just as long as I don't have to resort to 'File' to get at them and save to them. (Unless it can be done cleanly)
folder/application.jar
folder/resources/abc.png
If you could ../ back one from where the ClassLoader is looking it would be easy to cleanly get data from the directory that actually contains the jar file
Pipeline.getResource("../resources/abc.png");
Any ideas?
This isn't really what class loaders are meant for. Loading resources from the class loader is meant so that you can bundle up your application as one package and components can read each other without worrying about how the system you're deploying to is setup.
If the file in the JAR is meant to be changed by the app, then it isn't part of the app and thus probably shouldn't be in the JAR.
I don't have a lot of context on your app, but hopefully my suggestion will be valid for your situation.
I recommend setting a requirement in your app that it has a work area to which it is allowed to read and write and accept a configuration setting that specifies where this directory is. Typical ways to do this in Java are with environment variables, system properties or JNDI settings (for container deployments).
Examples:
Tomcat's startup scripts figure out where it is installed and sets a system property called catalina.home and allows you to over-ride it with an environment variable called CATALINA_HOME.
JBoss looks for JBOSS_HOME
Java application servers typically look for JAVA_HOME to find the JDK.

Uploaded image only available after refreshing the page

When I upload a picture, the file is successfully saved and the path is successfully set. But the uploaded image is not displayed immediately after the form submit. Only when I reload the page, the uploaded image is displayed.
I'm saving the uploaded file as below:
InputStream is;
try {
File file = new File("C:\\****\\*****\\Documents\\NetBeansProjects\\EventsCalendary\\web\\resources\\images\\uploadPhoto.png");
is = event.getFile().getInputstream();
OutputStream os = new FileOutputStream(file);
setUserPhoto("\\EventsCalendary\\resources\\images\\"+file.getName());
byte buf[] = new byte[1024];
int len;
while ((len = is.read(buf)) > 0) {
os.write(buf, 0, len);
}
os.close();
is.close();
} catch (IOException ex) {
System.out.println(ex.getStackTrace());
}
Why is the uploaded image only displayed after reloading the page and how can I solve this?
You're writing the file straight into the IDE's project folder and your intent seems to save the file in the webapp's deploy folder. This is a bad idea and well due to the following 3 main reasons:
Changes in the IDE's project folder does not immediately get reflected in the server's work folder. There's kind of a background job in the IDE which takes care that the server's work folder get synced with last updates (this is in IDE terms called "publishing"). This is the main cause of the problem you're seeing.
In real world code there are circumstances where storing uploaded files in the webapp's deploy folder will not work at all. Some servers do (either by default or by configuration) not expand the deployed WAR file into the local disk file system, but instead fully in the memory. You can't create new files in the memory without basically editing the deployed WAR file and redeploying it.
Even when the server expands the deployed WAR file into the local disk file system, all newly created files will get lost on a redeploy or even a simple restart, simply because those new files are not part of the original WAR file.
You need to write it to a fixed path outside the project/deploy folder instead. For example, /var/webapp/uploads. Then, to get it to be served by your webapp, just add it as a new web application context to the server.
Based on your previous question, I know that you're using Glassfish 3.1. In this server, it's called a "virtual host". You can configure it at server level in the admin console at http://localhost:4848 > Configuration > HTTP Service > Virtual Servers, or at webapp level by adding the following line to the /WEB-INF/glassfish-web.xml (your IDE should have autogenerated one; note that this file is before Glassfish 3.1 called sun-web.xml, so if you're seeing manuals/blogs/tutorials referencing it, yes it's exactly the same file):
<property name="alternatedocroot_1" value="from=/uploads/* dir=/var/webapp" />
Either way, you should then be able to use http://localhost:8080/contextname/uploads/* to serve those uploaded images from by <img> the usual way.
See also:
How to upload files to server using JSP/Servlet?
Recommended way to save uploaded files in a servlet application (contains a Tomcat configuration example)
Reading/writing a text file in a servlet, where should this file be stored in JBoss? (contains JBoss configuration example)
Simplest way to serve static data from outside the application server in a Java web application

Can multiple log4j.properties files be used in the same Tomcat web app?

I'm writing a custom extension to an off-the-shelf Java web application. The application uses log4j for logging and I'd like to add a new logger and appender specifically for my extension. The problem is that the application manages the log4j.properties file which is dynamically generated based on selections in an admin screen UI. Since this is an "off-the-shelf" application, I can't modify the source code. So, if I add my own logger & appender(s) to the file, it gets overwritten anytime an admin changes logging preferences in the UI.
Is it possible to get log4j to get it's configuration from 2 files? For example, I'd want something like the following:
applog.properties #(Dynamically generated from admin UI)
mylog.properties #(My static properties)
In this scenario, log4j would somehow combine the entries from both files for the complete configuration.
Is this possible? or are there other workarounds?
I never did find a way to "merge" multiple log4j.properties file, but I did find a workable solution. log4j configuration can be manipulated programatically at runtime similar to the code snippet below. This effectively merged my custom log4j settings into the configuration defined by the log4j.properties file, which in my case I couldn't edit.
// Init custom logging
// Define layout
PatternLayout layout = new PatternLayout();
layout.setConversionPattern("%d [%-5p] -- %m%n");
// Create appender
RollingFileAppender appender = new RollingFileAppender();
appender.setFile(LOG_PATH);
appender.setMaxFileSize("2MB");
appender.setMaxBackupIndex(0);
appender.setLayout(layout);
appender.activateOptions(); // It didn't work without this
// Get our logger and add appender.
log = Logger.getLogger("[MyCustomLogger]");
log.setLevel(YOUR_LOGGING_LEVEL_HERE);
log.addAppender(appender);

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