Is there a way to include whole Java source code into an eclipse project so the program is easier to debbug (e.g. by inserting println in methods you otherwise couldn't insert anything)?
I have a bug in my code. But to better understand why the bug in my code appears, I'd like to see what intermediate results in some system method (on which use the bug occurs) are.
For example, I'd like to know what JViewPort.scrollRectToVisible() exactly does and how my input behaves in it by printing out some intermediate results that occur in the method itself.
EDIT:
Instead of using JRE System Library X, I want to add the source code from JDK as if I had written the code myself. I want to be able to edit any System class just as I am able to edit any class I created myself. I want editable .java files, not packed .jars...
You would need to add the 3rd-party library to your Eclipse workspace as an project. (How you would do that depends on the code you are dealing with.) Once you have done that, you can hack your copy of the library to add trace prints etcetera.
A better alternative is to simply attach the source code for the 3rd-party library so that the debugger can show you source as you step through the code, set breakpoints,. Then use "advanced breakpoint" techniques instead of trace prints; e.g. http://www.vogella.com/articles/EclipseDebugging/article.html#advanced
You cannot change the library code, but you can view it by using de-compiler. The max you can do is this. Now if you change any code in the libraries which you reached via the de-compiler, you would find an error stating "the integrity of the .jar package has changed which is not allowed"
Eclipse have built-in support for what you wanna do.
All you have to do is set breakpoint and execute application in debugging mode.
You can use these icons in Eclipse debugging perspective.
Follow along Eclipse Debugging Tutorial for details.
Related
I was wondering if the way Java/JVM works means debugging tools like Eclipse can show me a list of all instances of a given class? I suppose one could write some reflection code but I don't want to break execution at the same place every time... rather I;d like to break execution and bring up a list of all MyClass123 objects in a debug window.
Is this even possible? Is it provided in Eclipse or any plugin?
Yes, it's possible in the standard eclipse debugger. See here. While debugging, right-click on a variable entry in the 'Variables View' and then click on 'All Instances':
This will open a list like this:
You may want to instatall Eclipse Test & Performance Tools Platform plugin in your application and perform MemoryAnalysis. This gives you details around all different objects in memory and their references.
You will not need to put any breakpoint in the code. It will gather the required data on its own.
What is it and how do I get around it?
Also, I want to use this code in my Java screen recorder, but I want to provide a vector of images as I click the screenshots rather than reading it frm a folder. I would like help with that, too.
for berry120:
In terms of the "access restriction" error, it seems to be a similar issue to this one - as in you may be trying to replace a Java library class with one from a jar file (in your case JMF.jar.)
Have a look at this question: Access restriction on class due to restriction on required library rt.jar?
The second answer down (one with 250+ upvotes) is the one that may work in your case - remove and re-add the JRE system library.
I'd like to add a custom warning message (i.e. add an entry to the Warnings section of the Problems tab) for .java files in Eclipse.
While I've found information (here and elsewhere) on creating plugins and using markers, I haven't yet found anything which talks about extending the "problem-finding" process. Most of the articles I've found don't discuss when to create markers, only how, and those that do assume that I'm interested in attaching them to a custom build step or custom editor, neither of which seems appropriate for what I'm trying to do.
How can I create a warning which functions like those available via Window > Preferences > Java > Compiler > Errors/Warnings?
I think that a builder might be appropriate for what you want to do. There's a template in the new plugin wizard that creates everything you need for a builder (ex. business logic). Since the builder runs every time the file is modified, you can clear the old warning (code generated for you) and add a new warning (code generated for you) if applicable. This also applies when the file is first created.
You could even look through the code and find hard-coded strings and flag them with warnings if you want.
As for the comments marking translation keys in the code today, those are there to guide NLS tools (you probably already knew that). The idea was to write the code first and then go back later and translate. If a change is made to the code later, the tools can run again and only act on new strings added by the delta.
I'm struggling with Java Refactoring - I need to write an Eclipse plug-in which will refactor some code. It's really difficult for me and it would be way easier if I could follow working code step - by - step. The only alike example I could find is a sample Introduce Indirection.
Unfortunately I cannot make it actually work. I get "chosen operation is not currently available" information anytime I try it.
I've imported code, "Run As -> Eclipse App" and than tried to use Introduce Ind. from Eclipse Articles. What am I doing wrong?
I'll be happy with any help :).
Check your handler class for isEnabled() method. I suppose when creating new handler the default value for this method returns false. That can be the issue.
You should be able to get that example (as written) working, or perhaps you need to open a bug. When you start their example in Run As, is there any errors in your error log?
Something else you can try is to look at some of the workbench refactorings. See org.eclipse.ltk.internal.ui.refactoring.actions.MoveResourcesHandler which sets up the move resources refactoring, and http://wiki.eclipse.org/FAQ_How_do_I_find_a_particular_class_from_an_Eclipse_plug-in%3F if you need help tracking down the SDK classes using CTRL+SHIFT+T
I've managed to run it. For others who'll face the same problem:
Check the basics:
Remember that you can chose only one method and:
It must exist in the model (http://help.eclipse.org/helios/index.jsp?topic=/org.eclipse.jdt.doc.isv/reference/api/org/eclipse/jdt/core/IJavaElement.html)
It must not have any errors
Must not be a constructor
Must not be connected to annotation declaration
And:Select a Java method in the editor outline or the Package Explorer
And it gets obvious :)
The action handler class should be impediments with related interfaces (Check for error console for identify what are the missing interfaces, most probably this would be 'IActionDelegate').
I have been wracking my brain trying to figure this out. For the first time I used jEdit the other day and I was pleasantly surprised that it auto indented my code (meaning that I'd put in the following code:
int method () {
_ //<-- and it put me here automatically
I've tried to get the same thing working with eclipse but with no success. I got into the code formatter but I don't see how to make that happen.
Is it possible to do this? Also while I'm here, is there a such thing as a eclipse plugin that will allow you to search the methods and classes of the standard java library?
Thanks
Personally all I use for this is the format options Window->preferences under Java->Code Style ->Formatter.
I once took the time to tweek how I like my code to look like when I work and exported the whole thing. After that I just code without too much bother on what it looks like. When I find the code looks messy by pressing the combination ctrl+shift+f and the whole class becomes pretty again, comments and all.
After a while it pretty much became a reflex...
code code code
ctrl-s, ctrl-b (cause I disable auto build sometimes), ctrl-shift-f
code some more etc...
Once I got used to this I never really cared how it presented the code as i was typing because I knew it would look all pretty as soon as the loop/if/switch/method etc is finished
My clean eclipse install does this by default.
Have you changed any options? Make sure the file you are editing has the .java file extension. The preference options that control the typing automations are under Java -> Editor -> Typing in the Window -> Preferences menu.
Also, I find that the auto-indenting, and most of the other auto-complete functions of eclipse do not function well if the file I am editing has errors in it which prevent compilation. Make sure that your curly-braces are matched correctly, this is the main one that I've noticed blocks auto-indent.
Regarding searching through the standard Java libraries, use the Search -> Java.. menu option, and check the JRE libraries checkbox, then search away. You can also use the Hierarchy view to see how the classes relate. Also, in the Package and Project views you can expand the JRE System Library, and then expand rt.jar which holds pretty much all the standard Java pacakges.
Eclipse has always done this for me by default.
One really cool thing about eclipse is that you can search preference pages. Just right click and go to prefrences. Go to the "Window" menu, and click "Prefrences". Then at the top of the tree view there's a text box that says "type filter text". Replace that with "indent" and it should bring up the page where the indent option is.
Make sure that eclipse recognizes your file as a java file, that you're using the Java distribution, the latest version, etc.
Iv been trying to work around the eclipse indenting and other supposed features for years, and it seems that the bottom line is this ...
It only works for the programming style of the authors, so to use it you need to modify your style to comply.
This would be OK except that the authors of eclipse have some very strange ideas about common shortcut keys.
One horrid example is the search features, eg when did Ctrl+K become "Find Next occurrence" and why doesnt F3 or n work?
That all being said I use eclipse because if you have the time to wait around while it starts up - or never close it - and you can modify everything youve learned about using an editor - why why why - then it will certainly increase your efficiency.
Please note that there is a preference setting for indenting, it can be set for a project, a workspace, or globally, but no matter how you set it eclipse will still chuck tab characters in where you dont want them.
In fact its indent crazy, like it wants to indent everything, even if its already indented.
Like I said Iv been using it for years and it STILL drives me nuts with its random behavior.
Follow these steps for Eclipse:
Select all text: ctrl+A
Correct indentation: ctrl+I
You should check:
Hidden features/tricks for Eclipse?
What is your favorite hot-key in Eclipse?