Why the intellij code autocomplete doesn't work? - java

When i try to use the code autocomplete of intellij by using ctrl+space it dosen't work.
What i need to do?
example:
In this code i want to use the add method of List and it dosen't give me the option to.

Several possible reasons:
Your file doesn't reside in a content root and is not bound to a build path, so it doesn't get the required class definitions and resources needed for code completion. To fix, right click your root source directory -> Mark Directory As -> Sources Root.
Check to see if you accidentally turned on the Power Save mode (File | Power Save Mode). Turning it on minimizes power consumption of your laptop by eliminating the background operations, including error highlighting, on-the-fly inspections, and code completion. Turn it off.
Make sure the JDK for your project is set up correctly in the File | Project Structure window.
A file containing classes and methods that you want to appear in completion suggestions list is marked as a plain text file. To fix, right-click on the file -> Mark as Java class.
External libraries that contain methods that you want to appear in the completion suggestions list are not added as dependencies or global libraries.

Related

Use a Java file that is in a different place than the rest of the project

I have a java source file in my project, that I want to move to an entirely different location than the rest of the files (my unix home dir), but I still want to be able to properly use it in my project. Is there a way to do this?
EDIT - I see there is a vote to close this for being unclear, so - let's say you have a pJava project in Eclispe. All the source files are neatly saved in their relevant packages, under the same directory. Now, I want to move one of the files to somewhere completely different, but still have it used in my project. I hope this clarifies
Thanks!
I suggest that it depends on what your reason is for moving the source file.
The Java file is still conceptually part of this project, but you're moving it for general organisational purposes. In which case, the new "completely different" directory is another place where sources should be read from, which most IDEs will call a "source root". You should configure your project to read sources from there as appropriate for your IDE.
You're moving the file because it's distinct from this project. In which case I would suggest it ought to be a separate project in its own right. In order to still use the logic in your original project, you'd build the new project into a JAR, and then bring in the JAR as a library dependency (either directly, or using some dependency management system such as Ivy/Maven/etc.). Again, the details will depend on what your current setup is.
Right click on your Eclipse's project -> properties -> java build path , and under the source tab click Link source then choose the parent folder of your java file .

Eclipse - Source not found

I know this question has been asked many times before, but none of the proposed solutions resolve my issue (or I'm not implementing them correctly).
I'm developing a plugin for OpenFire, and when I set a breakpoint in my plugin source Eclipse reports "Source not found". The JAR is built separate from the build of the OpenFire server. I've tried adding the JAR and specifying the source code directory, but no dice.
Here's the process I'm following: When I hit my breakpoint I'm clicking "Edit Source Lookup Path", clicking "Add", Java Library, User Library, click User Libraries, adding my library (tried both "Add JARs" and "Add External JARs"), and then specifying the folder that contains the source code. I've also tried:
Adding the source by selecting "File System Directory" instead of "Java Library"
Adding it by selecting "Workspace Folder"
In the Project Explorer, adding the source for my plugin to the Java Build Path
In the Project Explorer, adding my JAR as a Library and specifying the Source attachment
Thanks in advance for any suggestions.
Personally, I have no good experience in Eclipse JDT, when adding a source folder at the time it hits a break point. What I always prefer to do, is adding the source folder before debugging:
Select Project/Properties/Libraries
Select your library and "edit..." the source attachment
Select either the corresponding source folder or the zip/jar containing the package
After that, you should be able to open the source files in the virtual "Referenced Libraries" folder (directly below the "JRE System Library" folder inside the project), or when opening a reference to a linked class file from within the JDT editor. If you are able to access the source, then you should also be able to at least stop at the break point and see the corresponding source.
Else, you will have to check again, if the source folder is really valid: The source folder or source archive must contain the folder with the name of the root package of the library (e.g. the default Java "src.zip" inside the JDK folder also includes a corresponding "java" folder at its root). When in doubt, extract the archive and select the parent folder of the package you are interested in - sometimes source archives might be a mess or incompatible to JDT.
If this has been assured and it still doesn't work, chances are, that your linked source folder does not correspond to the compiled version of the library. Usually JDT will handle such inconsistencies fine, but if you try to open a source file, that is entirely different than the corresponding class file, you will encounter problems. In this case I would suggest either downloading the correct source version of the library, or recompiling the library from the source, if all else fails.
If opening a referenced source file from withing the JDT editor does work fine, and you are still unable to open the source files when a break point is entered during debugging, then most likely the class files are missing the line numbers of the corresponding source file. Again, you will have to recompile the library from the source in this case.
Finally, it is also possible to overwrite the default source lookup by specifying source folders or archives in the source tab of the launch configuration. But you should normally not need to do this, when your build path is configured correctly. From the Eclipse Help:
The Source tab defines the location of source files used to display source when debugging a Java application. By default, these settings are derived from the associated project's build path. You may override these settings here.
I had this very annoying problem for a long time but was finally able to solve it. In my case, a null pointer exception was being thrown somewhere in Java's Transformer.IsRuntimeCode(ProtectionDomain) function.
I didn't really need to know about this since the exception was being caught and handled, but eclipse would pause debugging every time this happened and tell me that the source wasn't available. As a result, I constantly had to keep pressing the button to continue code execution.
In order to prevent this from happening, I:
1. Clicked on the "Breakpoints" window at the bottom of the debugging
screen
2. Right clicked "NullPointerException"
3. Unchecked "Caught"
This prevented the debugger from pausing program flow during a caught NullPointerException.alt text
(source: SharpDetail.com)
And this another one as:
Eclipse doesn't crash. You're trying to step into a method, where eclipse doesn't know where to find the source (*.java) files and informs you about this. Here is how to tell eclipse where to look. Go to
Window->Preferences->Java->Installed JREs,select the JRE you are using and click Edit.
There, select all of the jar files in the list you see and and click Source Attachment....
In the window that shows up, select the fille src.zip, which is in your JDK folder (if you didn't uncheck it while installing the JDK). On the machine I'm on right now, that is
C:\Program Files\Java\jdk1.7.0_07\src.zip.
Save all your changes (possibly restart eclipse) and you won't see that error again.
Well it turns out the solution was anticlimactic. When Balder's recommendations did not work I tried debugging one of the stock OpenFire plugins and it worked just fine. I then created a new plugin from scratch, and by doing nothing other than adding the source to the project (Right-click on the project -> New -> Source Folder) it also worked just fine. I have no idea why Eclipse refuses to see the source for my original plugin, but I moved all my code and libraries over to the new plugin and debugging is working as expected.
Many times you put jar files in eclipse IDE as referenced libraries when binary version of application was downloaded. Usually done so by configuring the build path. But the binary does not have the source files. You have Binary version and source version of application.
One simple way is to download the source libraries that you also use maven to build the project.
Keep somehwere, may be inside your project workspace.
Now while seeing the class file (from eclipse, jar exploded) you may see the source not found, fine.... there is a button below and click on that, a new window opens and there select add external folder.
Reference it to the src folder of the source you downloaded(not the binary one) and kept somewhere as said above and it will show the class details from that.
I fixed this issue with doing the following:
Click at the menu Window - Preferences - Debug - Step Filtering And check all the packages like the following image.
(Step Filtering)
Then, debug again your project and thats it.
Best regards,
In my case, I had a breakpoint in the class declaration. I mean in the next line.
public class GenerateInterface implements JavaCall {
So, the debugger stopped in that line and showed the following message:
Source not found
I think unconsciously activate the breakpoint in that line.

How to debug Java code when it is out of sync?

One of the problems I'm running into is that my jar files and my source files don't match.
I'd like to:
Be Notified when when source and binary don't match (I think Visual Studio can do something like this...)
Set break points not by line, but by function. For example, set a break point at the entry of function foo().
I use eclipse mainly; so Solutions for eclipse would be most appreciated, but any IDE (or command line debugger) will do.
Thanks!
When developing just use and link to .class files that are saved by your IDE.
If your project starts to grow to a point where it's really useful to link to a .jar you're better off treating the jar's as separate projects.
Go to Project tab in Eclipse and then
click clean: Project->Clean…
click build automatically: Project->Build automatically
Use method breakpoints instead of line breakpoints. They can be set to halt on entering/exiting a method. You get them by double clicking the left editor side in a line containing a method declaration.
The debug information is limited to line numbers in the source file... I do agree that having a warning that the lines are wrong would be nice, but that would require more meta data in the jar than I think is available...
You might want to consider addressing the challenge with a change in your build process. This isn't exactly answering your question, but hopefully it will give you a strategy that will address the underlying problem.
When you generate the jar for deployment, also generate a jar with the binary AND source. For investigating the source code of a stack trace on the live server, set up a separate project in eclipse and have the binary+source jar be on the classpath. You may have to explicitly set the source code location back to the same jar (though I think Eclipse will just do this automatically).
Then you just have to add copying of the binary+source jar into the appropriate location in your workspace as you do your deployments (preferably with a deployment script).
If it's your server, you may want to even consider deploying the binary+source jar to the live server - that way you will always be able to get at the source.

Can Eclipse have multiple output folders just like multiple source folders

I have an Eclipse project, which has two source folders - 'src', and 'test'. I would like the build from both these folders to go into separate output folders.
The reason being, both these folders have a property file called ServiceProviders.properties which has different values for production and test runs of the code.
The problem is, since there is only one output folder where all compiled classes are copied, the properties file in 'test' does not get copied, and as a result my test code gets the production version of the properties file. I guess I am trying to simulate the way we can have different classpaths in Maven (and their lookup order).
If this does not work, I will use a JVM property to specify certain values which I can use in the test case. However, it does not seem like an elegant solution.
Using Maven will get this to work, but I cannot use Maven in this project.
Update 1:
Thanks for both the answers. Since they were identical, I have accepted the one which was posted earlier.
Upadte 2:
Even though I could get multiple output folders for corresponding source folders, it did not solve my original problem which was to load a ServiceProviders.properties from test when I run test cases, and the one from src when I run the app on a server from Eclispe. The way I got it to work is by creating a separate jar file with ServiceProviders.properties file from the test folder. In the run configuration of my test cases, I add this jar file and change the order, so it appears as the first dependency for lookup.
Yes it can, i just have checked that.
If you go into Properties of your Project, and there to Java Build Path, where you choose your different Source-Folders, there also is an option called "Allow output folders for source folders", which, if checked adds an editable output-folder for each of your source-folders.
just select it and click the edit-button and you're fine
Easy: click "Allow output folders for source folders" on the Java Build Path | Source tab. Then, when you expand each folder's settings, you get "Output folder"
In the PackageExplorer view click on the source folder and select "Configure Output Folder..." You can now configure the output folder separately for each source folder.

How can an Eclipse plugin access the project directory?

Is there a way to get the directory of a project in Eclipse? We are writing a plugin that will allow the user to select files, and then run some processes on those files. I would ideally like to be able to get all the files with a certain extension, but that is not necessary.
sure:
ResourcesPlugin.getWorkspace().getRoot().getProjects()
will get you a list of all the projects in the workspace. you can easily iterate to find the one you want. At that point, you can look for certain files by extensions, etc.
If you want to enable your users to select files inside eclipse workspace with a certain extension, you can look at the class org.eclipse.ui.dialogs.ElementTreeSelectionDialog (org.eclipse.ui.dialogs plugin)as a start.
Then, to have an example on how to make it filter extensions, you can look at the class org.eclipse.jdt.internal.ui.viewsupport.FilteredElementTreeSelectionDialog (org.eclipse.jdt.ui plugin) to see how they do it and then reimplement the stuff.
This should give you a higher level of action than going threw files inside projects by hand and reimplement dialogs.

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