So I have a problem: I have a Java project that connects to a DB and has some logic then answers via a RESTful Webservice request.
The thing is the connection do my DB was fixed (only connected to one DB) and hard to change because in the end I create a .war file, so for someone to use the .war it had to use the same DB connection settings and names.
Therefore I created a .properties file inside WebContent/WEB-INF/ (so the path is WebContent/WEB-INF/config.properties). When I run the project locally it works fine, the minute I run it on the Apache Tomcat Server it says he can't find the path specified, thus the NullPointerException.
Would appreciate if someone could shed some light on the issue. Thanks to all.
PS: Sorry for mispelling and bad formatting.
When you create a WAR the path of all the files are set relative to the context root (though in actual file system you can still figure it out in tomcat/jboss etc. it is not recommended to access files that way). The files can be got hold of through standard getResourceAsStream with relative path to the files /WEB-INF/config.properies
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I'm looking for the 'best practice' way to access resource files (for example a bunch of .xml files) as well as the folder structure in which they reside, regardless of the application server used.
Right now I'm using Wildfly 8 server and I access all src/main/resources/xxxx by getting the application real path then using Paths.get(resourcePath) as well as Files.walk(Paths.get(folderPath)) if I want to access a folder's files.
However, I faced a problem when I tried to deploy to Weblogic 12c, because this app server actually takes everything under WEB-INF/classes and creates a .jar file and adds it to WEB-INF/lib. I can still access singular resources using classLoader.getResource(resourcePath) but for some reason when I try to create a new File(Paths.get(resourcePath) or use Files.walk(Paths.get(folderPath)) it doesn't seem to be working. It throws an exception saying to file doesn't exist which I'm guessing is because it is not accessible since it is packaged inside a jar file.
I could potentially use classLoader.getResource(resourcePath) to access all my resources but unfortunately in my case I cannot know what resources will be available at compile time. I specifically NEED to be able to go through a selected folder's files and subfolders but I haven't found a common way to do it on both app servers, or ALL app servers for that matter.
Bonus points if the solution uses the new File api instead of creating a bunch of FileReaders but I'm ok with that too.
You could place the XML files in a folder /WEB-INF/xml and then use the ServletContext to obtain a File or Path for that location.
Variant 1:
call servletContext.getResourceUrl("/WEB-INF/xml") to obtain a URL and convert this URL to a File or Path. But depending on the server this might return a non-file resource URL, e.g. a jndi:/ url.
Variant 2:
call servletContext.getRealPath("/WEB-INF/xml") to obtain a file string and convert this URL to a File or Path.
I uploaded files to the server using BLOB db type on play framework. In the application.conf file I have
attachments.path=home/dotcloud/uploads
But I couldn't find the files on the server.
The issue is that if I restart my www service, then I lose all my files, I only have the db records.
I believe that there are two issues in here. First your path lack a initial '/' to be a full path (I'm assuming that was your intention):
attachments.path=/home/dotcloud/uploads
Second, I'm not sure that your Play server will have rights to write to that folder, as it's outside the application context path. Default folder is local to the application and Play can write it, not so sure about other folders though. You should double check that.
I am facing a problem with file upload.I have used Apache Commons
servlet file upload for uploading the file. Though the file is getting
uploaded and the data is getting stored on the local server(http://
127.0.0.1:8888/_ah/admin/datastore) but it is not going to the Google
App Engine datastore.
What I am doing is loading
the file as a stream and immediately parsing the stream and creating
datastore entities with the data. I am not actually trying to save the
file. In the local server it works. It even works when I try to access
the local server from another machine. However it does not work when I
deploy it to Appengine using the Google Pluggin for Eclipse. My parsing
code depends on resource files which are under the web-inf directory.
Is it possible these resource files are not getting uploaded and is
there a way to check what files are uploaded on Appengine?
Whatever's in your .war is going up into AppEngine. I don't see how parts of it will be selectively excluded. What's more likely is that your application is depending on stuff that is lurking SOMEwhere on your PC but not included in that .war file.
However, shouldn't your application be checking for those resources and throwing exceptions if they are not found? If it's failing silently, I'd consider that a design flaw.
Logging a lot may help you debug the problem. You can look at your program's logs via the AppEngine console. I recommend more error checking and logging.
Something else to check for is to not be running the version of your software you think you are. There's a kind of versioning mechanism that allows you to deploy different concurrent versions of your and only one will be actually accessible. One of the things you should be logging and/or making otherwise accessible is some version information (perhaps even including a build timestamp) for your app's build.
The files in the .war folder are executed in the app engine and the others are uploaded. What you need to verify is the path you have set and the path of you source java file and the file you are reading. You cannot use the local file system path in app engine. You need to include the file in your project
Consider the following example structure
- Project
- www
- files
+ documents
+ html
+ images
+ scripts
- WEB-INF
* web.xml
The documents folder needs to be a symlink or in some other way external from the war file because users will add and remove documents (through a mapped network drive).
I'd like to deploy the webapp as a war-file but I don't know how to do that and take the above into account. Could you give some pointers?
/Adam
If it's static content, maybe you'd be better off fronting your app server with a web server and putting the static content there. You relieve the app server of having to serve up static data and save a network roundtrip to boot.
I agree with #duffymo.myopenid.com that fronting your app server with a web server that serves static content for certain URL prefixes is a good, clean solution.
If this isn't feasible in your environment or if you decide that you'd rather handle it in the web application itself, you could write a servlet that effectively does the same thing. For example, create a servlet that is mapped to the URL pattern /documents/*. This servlet could parse the URL (/documents/some/file.png) to determine a relative filename (some/file.png). It could then read and return the corresponding contents found in an external directory (/staticDocs/some/file.png).
Why not store the documents etc. in a database, then have the web-app access the database and allow users to pull files that way? Does it have to be a mapped network drive?
Otherwise if it's a matter of knowing what is there, you could always construct the jnlp file dynamically and pass file lists, etc. in as arguments (if they are server side).
Guess we need to know a little more about what you are trying to accomplish.
Basically, it's a webapp that aggregates information from various sources and generates documents. It's a requirement that users have the ability to create and upload documents manually from the network without being logged in to the webapp.
Putting the document location path as a context variable is definately doable. I guess it's the easiest way. /Adam
Unfortunately, for you .war files are .zip files at heart and .zip files do not support symbolic links. If you are ONLY deploying to a windows machine you may have luck using a shortcut file. However, I'm not sure if the app-server will like that (... probably not.)
I would recommend adding a configuration parameter to the application that allows the document folder's full path to be specified there. The default path should be relative ("./www/files/documents") so that the app works out of the box without additional configuration.
Many java web servers support "exploded war files" where you just unzip your .war file into the deployment directory. With tomcat you copy this to $CATALINA_HOME/webapps and you're done.
This should work for you.
What about creating an environment variable on your server that points to the directory the files are stored in? The environment variable may work better than a setting inside your WAR file because you could deploy your application in a new environment (maybe moving from DEV to PROD) without changing your WAR file.
From your java code, you can reference this environment setting with:
String docPath= System.getProperty("DOC_PATH");
In Apache Tomcat it may sometimes be appropriate to achieve reuse via the tomcat RewriteValve like this:
META-INF/context.xml:
<Context>
<Valve className="org.apache.catalina.valves.rewrite.RewriteValve" />
</Context>
WEB-INF/rewrite.config:
RewriteRule (.*)/login(/.*\.)(png|jpg|js|css) $1$2$3
Now the /appContext/login/ path will use the same images/js/css as /appContext/
Of course as with all regular expression based solutions to ANY problem, keeping the complexity of the expression low is important for performance.
Sounds like you need a web Content Management System (CMS).
I create a web application (WAR) and deploy it on Tomcat. In the webapp there is a page with a form where an administrator can enter some configuration data. I don't want to store this data in an DBMS, but just in an XML file on the file system. Where to put it?
I would like to put the file somewhere in the directory tree where the application itself is deployed. Should my configuration file be in the WEB-INF directory? Or put it somewhere else?
And what is the Java code to use in a servlet to find the absolute path of the directory? Or can it be accessed with a relative path?
What we do is to put it in a separate directory on the server (you could use something like /config, /opt/config, /root/config, /home/username/config, or anything you want). When our servlets start up, they read the XML file, get a few things out of it (most importantly DB connection information), and that's it.
I asked about why we did this once.
It would be nice to store everything in the DB, but obviously you can't store DB connection information in the DB.
You could hardcode things in the code, but that's ugly for many reasons. If the info ever has to change you have to rebuild the code and redeploy. If someone gets a copy of your code or your WAR file they would then get that information.
Putting things in the WAR file seems nice, but if you want to change things much it could be a bad idea. The problem is that if you have to change the information, then next time you redeploy it will overwrite the file so anything you didn't remember to change in the version getting built into the WAR gets forgotten.
The file in a special place on the file system thing works quite well for us. It doesn't have any big downsides. You know where it is, it's stored seperatly, makes deploying to multiple machines easy if they all need different config values (since it's not part of the WAR).
The only other solution I can think of that would work well would be keeping everything in the DB except the DB login info. That would come from Java system properties that are retrieved through the JVM. This the Preferences API thing mentioned by Hans Doggen above. I don't think it was around when our application was first developed, if it was it wasn't used.
As for the path for accessing the configuration file, it's just a file on the filesystem. You don't need to worry about the web path. So when your servlet starts up it just opens the file at "/config/myapp/config.xml" (or whatever) and it will find the right thing. Just hardcodeing the path in for this one seems pretty harmless to me.
WEB-INF is a good place to put your config file. Here's some code to get the absolute path of the directory from a servlet.
public void init(ServletConfig servletConfig) throws ServletException{
super.init(servletConfig);
String path = servletConfig.getServletContext().getRealPath("/WEB-INF")
Putting it in WEB-INF will hide the XML file from users who try to access it directly through a URL, so yes, I'd say put it in WEB-INF.
I would not store it in the application folder, because that would override the configuration with a new deployment of the application.
I suggest you have a look at the Preferences API, or write something in the users folder (the user that is running Tomcat).
The answer to this depends on how you intend to read and write that config file.
For example, the Spring framework gives you the ability to use XML configuration files (or Java property files); these can be stored in your classpath (e.g., in the WEB-INF directory), anywhere else on the filesystem, or even in memory. If you were to use Spring for this, then the easiest place to store the config file is in your WEB-INF directory, and then use Spring's ClassPathXmlApplicationContext class to access your configuration file.
But again, it all depends on how you plan to access that file.
If it is your custom config WEB-INF is a good place for it. But some libraries may require configs to reside in WEB-INF/classes.