Develop Reference

How do I add a directory to the eclipse classpath?

I'm attempting to run an already existing eclipse project created by another person.
After importing it to eclipse, and attempting to Run As->Java Application, it fails because it cannot find a .properties file in bin/resources
I printed out the classpath eclipse was using
logger.info(System.getProperty("java.class.path"));
and sure enough, it includes bin, and all the lib/*.jars, but not bin/resources. Copying the .properties file into bin makes the program work, but I wanted to understand how to add a directory to the eclipse classpath.
I tried several things, none of which worked
export CLASSPATH=$CLASSPATH:/home/me/programdir/bin/resources
This didn't work. I understand it's not a desirable way to approach the issue, but I had thought it would fix the problem (I have more of a windows than linux background so perhaps I am missing some nuances of system variables in linux)
Next up, I tried modifying the VM arguments in the Run->Configurations dialog in Eclipse
-classpath "/home/me/programdir/bin/resources"
No luck here either, which confused me, as I was sure it would work and seemed like a reasonable solution to a specific program needing one additional folder added to the classpath.
Next I tried modifying build.xml directly. I found the part that defines the classpath and added my own line for bin/resources, as follows:
<path id="classpath">
<fileset dir="./bin/resources" includes="**/*.properties"/>
<fileset dir="./lib" includes="**/*.jar" />
</path>
this too was unsuccessful. This perplexed me even more, so I commented out the entire path element, and the classpath printed out by the logger was unchanged, so it is apparent that whatever classpath eclipse was using, it certainly wasn't this one. This seemed to me the best solution, had it worked: the build.xml file could be checked in with the correct additions to prevent future users from experiencing the problem.
Next I tried the IDE approach. Run->Configurations->Classpath-> User Entries->Advanced and simply added the bin/resources folder. That worked perfectly, the program finds the properties file, all is well. However, I am dissatisfied that my previous efforts failed without me really understanding why. It seems that each one should have worked.
Additionally, I want to ensure that I fix this problem in such a way that it is captured by the code I check in so that subsequent users do not have to go through the same steps. My solution is thus not very satisfactory as I am not sure what actual piece of code changed, and thus cannot verify that the 'fix' is checked in.
How do you find the actual definition that eclipse is using for its classpath? I had thought it would be the build.xml classpath definition, but that did not seem to be the case at all.

In Eclipse, there is a build classpath and a runtime classpath. There is also the build output location, which by default is bin. You don't want to add resources directly to bin because Eclipse can delete its contents when doing a clean build. What you need to do is add a resources folder in your project to contain any non-Java files that you want included in your build output.
To include the contents of this resources folder in the build output (bin), right-click the project and select Properties. In the Project Properties, select the Java Build Path section, then the Source tab.
Use the Add Folder... button to select the resources folder from your project, then OK to save the changes. At that point, Eclipse will automatically copy everything from resources into bin when it builds.

This is for a maven project:
Right click on project
click on run configurations
click on the classpath tab (Oxygen Eclipse)
click on user entries
click on Advanced
first radio selection default should be 'Add Folders'
click OK

Follow these steps to get this issue fixed:
Right click on Project
Click on Run As and select Run Configurations
Click on the classpath tab (Oxygen Eclipse)
Click on user entries
Click on Add External JARs.. and choose the downloaded JAR file
Click Apply and run your project...

Right Click on the project-name in Package Explorer, select Properties, select Java Build Path on the left, select Source tab on the right, click on Add Folder, browse through the project's directories to select the resources folder or whatever you need to add to the eclipse classpath, hit OK, again hit OK. Done.

If you don't want the properties file to be copied to the bin folder, you can try the following:
Right click your project, select Build Path, select Configure Build Path..
Select Libraries tab
Select Add class folder..
Add your resource folder.

Netbeans doesn't see classes from referenced library

I'm using netbeans 7.2 with NBAndroid extension. In my android project, I'm referencing a library (ActionBarSherlock) that is not in jar (can't be, for some reason). The problem is, that netbeans doesn't see classes from that library and gives me errors (package does not exist etc.) However it builds and runs OK, the library is added correctly. Netbeans just doesn't see it.
Here is a screenshot.
Here is similar question, no solution package com.actionbarsherlock.app does not exist
Is there a way to fix this? Thanks for help!
EDIT: So I found a way to solve this, it's more a workaround than a solution. I created a jar file from the library classes called classes.jar. I put it in the libs folder, so netbeans sees it. Than I created custom_rules.xml (it's imported via build.xml). In it I move classes.jar away from the libs folder, so I can build it, and in the end I move it back.
<?xml version="1.0" encoding="UTF-8"?>
<project name="imported">
<copy file="libs/classes.jar" todir="./" />
<delete file="libs/classes.jar" />
<target name="-post-compile">
<copy file="./classes.jar" todir="libs/" />
<delete file="./classes.jar" />
</target>
</project>

The errors you see are because NetBeans doesn't recognize the packages, classes, methods, etc. When you build or run the program, NetBeans resorts to the Android project's Ant script, which apparently is configured correctly to find the classes. As far as compiling and running, you won't have a problem. However, if you want to use NetBeans' autocomplete and error-detection features, you need to configure it to detect your libs. To do this, just right click on your project name in the Project pane and click Properties from the context menu. Next, click on Libraries under Categories on the left. Then click Add JAR/Folder and navigate to the folder with your third-party library. You can select one of the options for the path then click OK. Now NetBeans should be able to find the identifiers and help you write your code.

Rather than doing some tricks in your build script I'd recommend you to use ActionBarSherlock as a library project. You should be able to do this in project customizer (select project, right click, choose properties).
Also see 'Including in YOur Project' bullet 2. in http://actionbarsherlock.com/usage.html
-Radim

Copied resources using ant in eclipse not appearing in jar

I'm using ant to build a project in eclipse. Before the jar is constructed, I want to move some files from another project into a resources folder in this project.
The problem I'm having is that none of the files show up in the jar.
Example:
<project>
<target name="A">
<copy file="../otherloc/file1" tofile="resources/file1" />
<waitfor><available file="resources/file1" /></waitfor>
</target>
<target name="B" depends="A">
<jar destfile="dist/jarfile.jar">
... (actually build the jar)
</jar>
</target>
</project>
So in the above case, "file1" doesn't actually make it into the jar, even though everything else in the resources directory does. Eclipse doesn't show the new file in the resources directory until I refresh, either. It's like, because eclipse doesn't know about it, it's not included in the build.
Any suggestions appreciated. I'm pretty much an Ant noob, so it's possible I'm going about this entirely wrong.
Edit: Alternately, is there some way to just include the file from the other project? I was a little unclear on the best way to get it into the jar. It needs to be in a directory along with some other existing project files.

Did you check both tasks independently?
First to have file1 copied in the proper location.
Then, if B fails to put file1 in the archive, the issue could lie in the tag. Are you sure resource/file1 is handled by a fileset ?

Unfortunately we haven't been able to resolve this, so we just work around it by separating the task into two steps and copying the files before running the build script. Not really a great "answer", but nothing else has been suggested.

Add a properties file to IntelliJ's classpath

I'm running a simple Java program from the IntelliJ IDE using the Run->Run menu. It works fine. Now I want to add log4j logging.
I added a resources folder under my project root.
I added a log4j.properties file in that folder.
I changed the code to log something.
What is the right way to tell IntelliJ to include the resources folder in the classpath so the properties file is seen?
With IntelliJ 8 I could guess like a drunk monkey and eventually get it to work. I have 9 now and I am wholly unsuccessful. I've been trying for an hour. How about an "Add to classpath" option somewhere? /fume /vent /rant

Try this:
Go to Project Structure.
Select your module.
Find the folder in the tree on the right and select it.
Click the Sources button above that tree (with the blue folder) to make that folder a sources folder.

Actually, you have at least 2 ways to do it, the first way is described by ColinD, you just configure the "resources" folder as Sources folder in IDEA. If the Resource Patterns contains the extension of your resource, then it will be copied to the output directory when you Make the project and output directory is automatically a classpath of your application.
Another common way is to add the "resources" folder to the classpath directly. Go to Project Structure | Modules | Your Module | Dependencies, click Add, Single-Entry Module Library, specify the path to the "resources" folder.
Yet another solution would be to put the log4j.properties file directly under the Source root of your project (in the default package directory). It's the same as the first way except you don't need to add another Source root in the Module Paths settings, the file will be copied to the output directory on Make.
If you want to test with different log4j configurations, it may be easier to specify a custom configuration file directly in the Run/Debug configuration, VM parameters filed like:
-Dlog4j.configuration=file:/c:/log4j.properties.

I have the same problem and it annoys me tremendously!!
I have always thought I was surposed to do as answer 2. That used to work in Intellij 9 (now using 10).
However I figured out that by adding these line to my maven pom file helps:
<build>
...
<resources>
<resource>
<directory>src/main/resources</directory>
</resource>
</resources>
...
</build>

I spent quite a lot of time figuring out how to do this in Intellij 13x. I apparently never added the properties files to the artifacts that required them, which is a separate step in Intellij. The setup below also works when you have a properties file that is shared by multiple modules.
Go to your project setup (CTRL + ALT + SHIFT + S)
In the list, select the module that you want to add one or more properties files to.
On the right, select the Dependencies tab.
Click the green plus and select "Jars or directories".
Now select the folder that contains the property file(s). (I haven't tried including an individual file)
Intellij will now ask you what the "category" of the selected file is. Choose "classes" (even though they are not).
Now you must add the properties files to the artifact. Intellij will give you the shortcut shown below. It will show errors in the red part at the bottom and a 'red lightbulb' that when clicked shows you an option to add the files to the artifact. You can also go to the 'artifacts' section and add the files to the artifacts manually.

Faced a similar challenge adding files with .ini extensions to the classpath. Found this answer, which is to add it to Preferences -> Compiler -> Resource Patterns -> [...] ;*.ini

If you ever end up with the same problem with Scala and SBT:
Go to Project Structure. The shortcut is (CTRL + ALT + SHIFT + S)
On the far left list, choose Project Settings > Modules
On the module list right of that, select the module of your project name (without the build) and choose the sources tab
In middle, expand the folder that the root of your project for me that's /home/<username>/IdeaProjects/<projectName>
Look at the Content Root section on the right side, the red paths are directories that you haven't made. You'll want to put the properties file in a Resources directory. So I created src/main/resources and put log4j.properties in it. I believe you can also modify the Content Root to put it wherever you want (I didn't do this).
I ran my code with a SBT configuration and it found my log4j.properties file.

For those of you who migrate from Eclipse to IntelliJ or the other way around here is a tip when working with property files or other resource files.
Its maddening (cost my a whole evening to find out) but both IDE's work quite different when it comes to looking for resource/propertty files when you want to run locally from your IDE or during debugging. (Packaging to a .jar is also quite different, but thats documented better.)
Suppose you have a relative path referral like this in your code:
new FileInputStream("xxxx.properties");
(which is convenient if you work with env specific .properties files which you don't want to package along with your JAR)
INTELLIJ
(I use 13.1 , but could be valid for more versions)
The file xxxx.properties needs to be at the PARENT dir of the project ROOT in order to be picked up at runtime like this in IntelliJ. (The project ROOT is where the /src folder resides in)
ECLIPSE
Eclipse is just happy when the xxxx.properties file is at the project ROOT itself.
So IntelliJ expects .properties file to be 1 level higher then Eclipse when it is referenced like this !!
This also affects the way you have to execute your code when you have this same line of code ( new FileInputStream("xxxx.properties"); ) in your exported .jar.
When you want to be agile and don't want to package the .properties file with your jar you'll have to execute the jar like below in order to reference the .properties file correctly from the command line:
INTELLIJ EXPORTED JAR
java -cp "/path/to_properties_file/:/path/to_jar/some.jar" com.bla.blabla.ClassContainingMainMethod
ECLIPSE EXPORTED JAR
java -jar some.jar
where the Eclipse exported executable jar will just expect the referenced .properties file to be on the same location as where the .jar file is

Right-click on your directory and from Mark directory as select Resources root as below:

Perhaps this is a bit off-topic, seeing as the question has already been answered, but I have experienced a similar problem. In my case only some of the unit test resources were copied to the output folder upon compilation. My persistence.xml in the META-INF folder got copied but nothing else.
In the end I "solved" the problem by renaming the problematic files, rebuiling the project and then changing the file names back to the original ones. Do not ask me why this worked but it did. My best guess is that, somehow, my IntelliJ project had gotten a bit out of sync with the file system and the renaming operation triggered some kind of internal "resource rescan".

This is one of the dumb mistakes I've done. I spent a lot of time trying to debug this problem and tried all the responses posted above, but in the end, it was one of my many dumb mistakes.
I was using org.apache.logging.log4j.Logger (:fml:) whereas I should have used org.apache.log4j.Logger. Using this correct logger saved my evening.

I had a similar problem with a log4j.xml file for a unit test, did all of the above. But figured out it was because I was only re-running a failed test....if I re-run the entire test class the correct file is picked up. This is under Intelli-j 9.0.4

Setting Different Java Class Paths in Eclipse

I have been given an application which uses a build.xml file for building purposes. I have very little knowledge of Apache Ant and the classpaths seems to be the following:
<!-- Classpath -->
<path id="development-classpath">
<fileset dir="${libs.dir}">
<include name="**/*.jar"/>
</fileset>
<pathelement location="."/>
<pathelement location="${classes.dir}"/>
<pathelement location="${configuration.dir}/langs/"/>
<pathelement location="${fits.dir}/xml/nlnz"/>
</path>
As I want to use Eclipse own building facilities I would like to assign these classpaths variable in Eclipse, which I don't have much experience with. How do I do it?

Go to your external tools configuration, select your ant build, and click on the Properties tab. You will probably have to un-click "Use global properties...". Then it is simply a matter of adding properties. This will allow you access to the variables built into Eclipse such as ${project-loc} and these properties will be available to ant as if you had set them in the ant file itself.

Here's the manual way to configure Eclipse to mimic what ant will do using the build.xml file. This should get you started:
Open Eclipse, open the "Java" Perspective. Right click the project and choose "Build Path / Configure Build Path". Alternatively click "Project" Menu, and choose "properties", then click "Java Build Path". Click the Libraries Tab. This is where you tell Eclipse where the jars needed build your project are located.
From the build.xml snippet, the first "<fileset>" specifies that all the jars you need are under the <project>/libs directory (I'm guessing that ${libs.dir} corresponds to "libs" but you might want to double check. It should be defined near the top of build.xml). So click, "Add Jars...", navigate into <project>/libs, highlight all the jars inside the directory and then click "Ok".
The first and second <pathelement> tags are telling ant to use the current directory and the classes directory. Eclipse should already take care of this by default, but to double check, click on the "Source" Tab (should be in the same "Java Build Path" dialog as the "Libraries" tab). The default output folder shows where eclipse will compile java code to .class files. The Source folders on build path shows where all your source code is that Eclipse should try to compile.
Finally, The last two <pathelement> tags tell ant to use some resource/config files under ${configuration.dir}/langs and ${fits.dir}/xml/nlnz. You can add these similar to the way you added the jars. Click "Libraries" Tab. Then choose "Add Class Folder" and highlight both the "langs" and "nlnz" folders.
Hope this give you some insight into where Eclipse looks for jar dependencies, class files and resources.
Having said all this, as you become more familiar with Eclipse and build tools, you'll probably discover that this probably isn't the best way to go because it's very easy for the build.xml and eclipse configuration to get out of sync. There are ways to tell eclipse to build using an ant build.xml file (check out File->New Project->Java Project form Existing Ant Buildfile). And there are also ways to run ant targets from within Eclipse (check out Window -> show view -> ant).

Probably you need to put build.properties files at same path which build.xml is.
This build.properties will looks like similar to this:
libs.dir=path_where_libs_are
classes.dir=path_where_classes_are
configuration.dir=etc
fits.dir=etc
This will allow to run your ant script with these configuration values inside and outside Eclipse.