Good morning to all.
I have two projects, one as Java Project, and other made with Play!.
Both projects are in Eclipse IDE.
I need to consume a method in Play! project from Java Project.
How can I do that?
Thanks for helping.
I've never used the Play Framework myself, but what you usually do is put the JAR-file you like to use the method from in the "lib" folder in your play project and tell your IDE to add the lib to your java classpath. I'm guessing you're using an IDE to develop your app (would be great if you could mention it in this case).
That should be enough to access the method from the java project and compile your code. I'm not sure if you need to configure the play project to access the lib at runtime.
For more specific help you need to provide more info what you actually want to do and what tools you're using.
Related
I have a simple Java .jar application, that is not for Android. I want to use ProGuard (Eclipse plugin), to obfuscate its code. However, I could not find any way to use ProGuard Eclipse plugin for non-Android java projects. Can anybody tell me how can I do that?
I can not use the original ProGuard GUI, because my application requires too much obfuscation configuration, that I can not re-enter every time I want to export my application
Thank you.
Is it possible?
I'm developing for a application server that in runtime give me access to some specific classes. I also have the javadocs related to those jars.
Importing all the deployed jar into Eclipse would be much harder than getting auto-completion working exclusively from javadocs.
No, it's not possible. You'll need the binary jars in the eclipse build path to be able to compile your source code.
I need to add some jars from JRE7 library to my Android project. But for example rt.jar is in conflict with android.jar from Adroid 2.2 SDK, so I get this error:
Ill-advised or mistaken usage of a core class (java.* or javax.*)
when not building a core library.
This is often due to inadvertently including a core library file
in your application's project, when using an IDE (such as
Eclipse). If you are sure you're not intentionally defining a
core class, then this is the most likely explanation of what's
going on.
However, you might actually be trying to define a class in a core
namespace, the source of which you may have taken, for example,
from a non-Android virtual machine project. This will most
assuredly not work. At a minimum, it jeopardizes the
compatibility of your app with future versions of the platform.
It is also often of questionable legality.
If you really intend to build a core library -- which is only
appropriate as part of creating a full virtual machine
distribution, as opposed to compiling an application -- then use
the "--core-library" option to suppress this error message.
If you go ahead and use "--core-library" but are in fact
building an application, then be forewarned that your application
will still fail to build or run, at some point. Please be
prepared for angry customers who find, for example, that your
application ceases to function once they upgrade their operating
system. You will be to blame for this problem.
If you are legitimately using some code that happens to be in a
core package, then the easiest safe alternative you have is to
repackage that code. That is, move the classes in question into
your own package namespace. This means that they will never be in
conflict with core system classes. JarJar is a tool that may help
you in this endeavor. If you find that you cannot do this, then
that is an indication that the path you are on will ultimately
lead to pain, suffering, grief, and lamentation.
I know there have been several threads about it and things like JarJar, OneJar or FatJar might be good for me. But I don't know how to make any of them work and documentation doesn't really make it clear (for me). I guess they use Ant commands, but I have always used Eclipse built-in builder and now I have no idea how to use neither Ant nor any of mentioned above.
So my question is: how can I repack this rt.jar so I could compile it in my Android project?
Thank you!
EDIT:
Ok, so what I want to achieve is to create a .jar, which can be used during developing Android application (simplifies some functionalities, doesn't really matter). But I would also like to be able to add the very same .jar to standard Java project in order to use some functions there as well. It would look like this:
Whoever writes an application adds this .jar to his Java project -> it enables him to generate certain files (internet is needed to do it) -> these generated files are then added to Android project -> later on, when somebody uses this Android app, these files provide certain functionalities without using internet (off-line).
It would be ill-advised to do this in any project at all, even if it were possible. You would be opening yourself to a wealth of class incompatibility and loading problems. But in any case it doesn't even matter because the core Java libraries are loaded way before your archives are even touched, making any such attempt at overriding them moot.
Not to even talk about the fact that Android is using its own JVM implementation which is not fully compatible with JDK 6 (forget JDK 7). Also note that it may be a copyright violation to package the core Java libraries with your code and could change your licensing options (IANAL).
You need to find another way to resolve whatever issue you are having (which you failed to mention in your question).
There are many JARs that work nicely on both Android and on classic Java. None involve having Android developers pirate rt.jar. Stick to java.* and javax.* classes that exist in both the Android SDK and in whatever level of Java you are supporting, and your JAR will work fine in both environments.
You should ideally refrain from using such .jar files, but if you must, you can add them to build path. But this, at times results in a conflict, like the one that you are facing right now. What you need to do to resolve this kind of a conflict, is:
add the jar in the build path.
Check "referenced libraries". The jar file should appear under the same.
once it features under referenced libraries, check the "android dependencies" virtual directory. If you get to see that you have an instance of the same jar file there as well, you should delete the "android dependencies" folder altogether. (Trust me, this does not affect your project in any way).
having done that, you should be able to compile your code without any further conflicts.
Happy coding.. :)
I developed an application in eclipse that uses many of the classes of the eclipse framework and requires eclipse to run. But now I'm being required to decouple it from eclipse and make it a standalone application. How can I do this?
You might have luck using File / Export... / Java / Runnable Jar File. This will create a standalone .jar file that should be possible to run without Eclipse. You may however need to experiment with the various settings to get it to behave exactly how you want depending on what libraries you are using.
In general however, I'd suggest using a proper build/dependency management tool such as Maven. This will take a bit of time to learn at first, but my experience is that it will make you more productive in the long run....
Start by commenting out the imports for the offending libraries. This will turn red any references to those libraries in your code. Then substitute a different library or refactor your code.
What do you mean by "decouple" it from eclipse? Do you mean you can no longer rely on any of the eclipse libraries, or that you simply don't want it running as a module in the IDE?
If it's the former, you have a lot of rewriting to do.
If it's the latter, then you'll want to basically bundle your module with an "empty" eclipse framework application. This doesn't "unbundle" eclipse, eclipse is still there, but now you don't have any of the IDE modules etc, and instead you have a stand alone ECLIPSE BASED application.
Create a standalone jar file from the Eclipse project as mentioned by Mikera, or you need to re-factor the code such that it doesn't depend on Eclipse libraries.
There is no point in creating a Java application which depends on certain IDEs or platforms. Java code should be independent (which is why it has the power to run on any platform which has JVM installed in it.
Try removing the dependency from your project to the Eclipse libraries. See if you can simulate the same thing using Standard Java libraries. If not, try to create a JAR for your project from Eclipse. If nothing works out, try looking for some 3rd party APIs.
trying to do some Android development, which means Eclipse, however, most of my experience is Microsoft tools (e.g. Visual Studio). My java experience is mostly either Blackberry dev in the JDE and some miscellaneous stuff back in the Java 1.0 days.
My question is this. In VS200x, there is a .sln (solution), .csproj(project), etc...
What are the equivalent file extensions for Eclipse? Do they even exist? I am having trouble with the basics, like how does one load a project into a workspace.
Is there a tutorial for Microsoft refugees somewhere?
Have a look here for "An introduction to Eclipse for Visual Studio users"...
Basically, for Java program (I never done any Android development) the basic Eclipse configuration files for a project are a .classpath (defining the dependencies of your project), and a .project file, that contains all specificities to your project configuration. In addition to that, a .settings directory is created, which contains some configuration files for plugins activated on your project.
Edit:
Eclipse is the most used IDE for the Java development. However, the best IDE is JetBrains IntelliJ IDEA. I see that there is a plugin for it to develop Android applications (here). If you can affort this wonderful application ($249), you will not regret it! You may eventually try the free 30 days trial...
You need to use file import and then choose Existing projects into workspace.
A .project file and a .classpath file will be created.
I find the Eclipse way of working to be incredibly frustrating having come from Delphi/JBuilder where a single project file held all your settings.
Make sure that you back up your workspace as well - there is nothing worse than recreating it when you are under pressure!
My 2 cents :
Make sure to version control your .project and .classpath. You may aslo want to use path variables to reference directory where the external dependencies (third parties libs) are located.
Are you doing it for fun or for commercial purposes? Because if money is involved, if I were you, I would really consider investing in IntelliJ, which is arguably the best IDE Java IDE out there, but unfortunately it is not exactly free. The Android SDK has some support for IntelliJ out of the box so it's not like you had to write all the makefiles yourself manually. If you liked Visual Studio, you would like IntelliJ, so why don't you download the trial version and have a look at it.
Just my 2 cents.