I am currently evaluating the Dropwizard framework for one of my personal projects. My intention is to use the Eclipse IDE for development. I've followed Dropwizard's "Getting Started" guide to successfully set up the basic 'Hello Stranger!' web service. My question is pretty basic but I haven't found any documentation/pointers so far and so here it goes...
How can I set up my dropwizard maven project so that I can set breakpoints (say, inside HelloWorldResource's sayHello method) and inspect/watch values of variables etc.?
I have created a debug configuration by specifying a Main class and setting "server hello-world.yml" as the Argument. When I try to debug, the service is started and works as expected but I am unable to set breakpoints or follow control flow.
You set breakpoints in Eclipse by double clicking the line you want to insert a breakpoint to.
Alternatively just right click on the left of line number you want to insert a breakpoint and click on "Toggle Breakpoint".
[Breakpoint Screenshot]
Then you want to open the Debug perspective (Window > Open Perspective Debug).
In debug you want to press the Run button (looks like a green play button) and it will stop at your breakpoint.
You can setup multiple breakpoints by the way for before / after a function call.
Related
I'm using Eclipse (Kepler) for a GWT application and for some reason, superDevMode keeps appearing in my arguments. We are stuck with GWT 2.4 which does not know what superDevMode is. I remove the argument, hit Apply and Debug to start the app, but when I look at the arguments again, -superDevMode is in there again. I am assuming there is some property that belongs to 2.6 (the version that was installed with the Eclipse plugin), but I can't seem to find it.
Update: Below, Adam recommended that I go to the GWT tab and take it out of superdevmode. Here is a screenshot of that tab:
There isn't a way to do that. The large area at the top of the tab (above the Super Dev Mode group) suggested that something was supposed to be there, so I set the project's GWT to 2.6. Sure enough, there was a Super/Classic dev mode selection. I set it to classic, saved the settings, and then put the project back to 2.4. The GWT tab looked exactly as it does above and the arguments now has "-nosuperDevMode" in it, which is also not recognized by 2.4.
Any help would be appreciated.
Thanks,
CC
I found a temporary workaround that comes with a caveat: I made the Eclipse Run Configuration file read-only.
Example path:
<YOUR_WORKSPACE>\.metadata\.plugins\org.eclipse.debug.core\.launches\<YOUR_RUN_CONFIG_NAME>.launch
Then whenever you bring up the Dev Mode Run Configuration in Eclipse it still shows the -superDevMode flag, but when you click the Close button it now asks you if you want to save and you can press No.
The big caveat: if you actually do want to change the Run Configuration Eclipse will ask if you want to save, you press Yes, the dialog closes, but it didn't actually save.
Easiest fix is to shutdown Eclipse, manually edit the .launch file to remove -superDevMode, make the file read-only, then start Eclipse again.
Here's the bug report.
Go to GWT tab (3rd from left) and switch from Super Development Mode to Classic Development Mode
I'd like to run my Groovy project in Eclipse using a shortcut (CTRL+F11). The trouble is, every time I do so I get a "Select a way to run " dialog, which gives me the choice between Groovy Console, Groovy Script, Java Application.
I've already set a Run Configuration to use Groovy Script, and if I click that Run Configuration under the Run As menu, it just runs.
How can I get my project to execute from a keyboard shortcut without that dialog popping up? I can't imagine ever selecting one of the other options.
I've never been able to get a satisfactory keyboard shortcut for Groovy script runs out of ctrl-F11. Instead I use alt-shift-X and then press G when the menu appears.
For debugging I use alt-shift-D, then G.
Both are two-stroke, rather than one-stroke, solutions, but neither one forces me to use the mouse or the arrow keys.
Under Project>Properties>Java Build Path and then click on Java SE, what ever it may be, click finish.
On the off chance that you deleted your java system library you can o pick up a new one... http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
In Netbeans I have the option of setting a "Main Project" which basically means if you hit "run", it will automatically execute the main class for that project.
This is convenient for various reasons, for example if you have one project depending on another project and you want to quickly test your changes in your main project.
Does a similar concept exist in eclipse?
Currently, I click on the desired project and then ctrl+F11 to run that project, but it would be convenient if I could just hit F11 or something without the extra action.
I had that same problem. My workaround is to make eclipse always launch the previously launched application. You can do that in settings, Run/Debug | Launching, in the Launch Operation section, select:
[x] Always launch the previously launched application
When you want to launch something different, launch it explicitly, and after that you can relaunch easily with Control F11.
This is very useful for me in practice, as most of the time I work on one thing and relaunch it several times, and rarely need to switch between launchers. (As an aside: in IntelliJ it's nice that I can easily switch between launchers using a simple drop-down list, without manually navigating to the other project/thing I want to switch to.)
Hi I am going to dig a little more in Java so I would like to see how the program executed in the core class. For example, I would like to know how String.chatAt() is implemented, so I set breakpoint and tried to step into with debug mode. But I failed, I set bp at the second line when the program hit it, I used step into it still continue to the third line.
String a = "1231231241241";
char b = a.charAt(0);
System.out.println(b);
I think it should go into the source and show "no source found" and then give me a chance to attach the source file, right? But why it cannot get in? I can only use ctrl+right click on a method to get into source and attach.
It might be that your Eclipse is not setup to run with JDK, it might run with JRE instead.
Check this link.
Also, I might suggest you to try and use Maven for your Java projects management, it makes the life so much easier, when you get a grasp of it.
Most likely, you have the "Step filtering" functionality activated.
When debugging, it can sometimes be a bit annoying when the debugger steps into trivial classes whose internals you were not really interested in. Because of this, you can configure "Step filters". Classes or packages that are added as step filters will be ignored by the "Step into" operation.
If you want to configure which classes/packages should be included in the step filter, you can go to: Window --> Preferences --> Java --> Debug --> Step Filtering
My guess is that you have a java.* package filter defined there, meaning that the debugger will never step into any class within a package which starts with "java". Uncheck this package filter if you want to be able to step into java.lang.String
Alternatively, if you want to activate/deactivate step filtering completely, you can do this by clicking the Use step filtering button in the debug view, as shown below:
To be able to look at the code of libriaries you are using in your project you should configure your build path by attaching the soruces and JavaDoc.
Source Lookup
Seems like you dont have the "Source Attachment" set. Go to Preferences -> Java -> Installed JREs. Select the JRE you use and click "Edit", then set the Source Attachment to the src.zip that comes with the jdk by selecting the jars and clicking "Source Attachment" :).
You can do this with all of the jars at the same time by selecting them via shift-click.
for example in this System.out.println("test") piece of code if you want to step into System class just click on System and click F3 you will be redirected to attach the source code if you haven't already attached.Just attached the src folder of the jdk
I have a problem with eclipse debugging. I had a proper working code and few hours ago I add one more external library to do something new. When I run the program now it works properly, but when I want to debug it, it stopped on the first line of a new part of the code (the one using the newest external library). It shows the info:
"Class File Editor
Source not found
The source attachment does not contain the source for the file ModelBuilder.class"
When I try to step over I just receive the same information but connected with other files. After stepping over a multiple times I finally get back to my code and can debug the rest of the program normally.
Of course I can do it always but does anybody know the solution to that problem, not to click step over multiple times but debug normally?
It should not enter the external library code unless you step into it, or there's an exception in that code. If you find yourself stepping through code you don't have source to, use Step Return, which jumps to the end of whatever method you're in.
If it is caused by an exception in the library code and you want to ignore it, go to Window > Preferences > Java > Debug and uncheck "Suspend execution on uncaught exceptions".
If you know what exception is causing the execution to suspend, then you could also try this:
Go to the Debug perspective
Open the Breakpoints view
Click the J with the exclamation point by it (J!)
Search for the exception that triggers the debug suspend
Uncheck the two check boxes
Say OK