Using Eclipse I was testing a simple app by running it on a device emulator. The application itself was working fine. I just had a thought of displaying some text on the console by means of System.out.print.
My app is merely a single instance of the Activity class. I imported java.lang.. For some reason, I was unable to display any text on the console with this: System.out.print("Hello");
Also, the Eclipse editor kept showing a warning that java.lang. was never used!
Was I doing something wrong? Or, does the Dalvik VM require something different from a Java VM when it comes to outputing text on the console?
Thank you.
There is no console like in Java. If you want to print debug information, use "logcat"
You can view these in eclipse.
If you have ever used i.e. the python logging module, the syntax will be familiar to you.
Related
Typically, when running an application from the command line, I get a nicely printed trace when things go wrong. But, since I happen to be working on an Ncurses application, the trace gets mixed in with the interface that was running, and the output gets all jumbled. Like so:
Specifically, I'm working on this project: todo-curses.
I'm running the app as a Rake task, so I figured the --trace option would help me, but I just can't seem to figure it out. Is there a good way to log the output of the app to a file or something and not include the Ncurses interface with it?
It depends on the application: curses writes to the standard output by default. If you (as the developer of the curses application) use newterm for initializing the library rather than initscr, then you can tell it to write the screen interface to the standard error.
But developers of bindings for curses from other languages typically leave out newterm as an alternative, just to make things simple. For instance, the Ruby curses shown on github has this deficiency. Perhaps a bug report is due.
While trying to use GWT Super Dev Mode, I followed those guidelines :
GWT-2.5-Super-Dev-Mode
Introducing Super Dev Mode
How does GWT's Super Dev Mode work?
However, I am stuck at the step trying to turn on Super Dev Mode :
Once I fully compiled my project, I run the code server and the dev mode, go at http://127.0.0.1:8888/myapp.html (without the ?gwt.codesvr=127.0.0.1:9997) and then click on the bookmark Dev Mode On. It detects my module, asks me to recompile, a glass screen appears with a message Compiling MyApp ... and then nothing ... No error, no stack trace either in Chrome or Eclipse. Just nothing happens.
Debugging the js code from dev_mode_on.js file, the script is interrupted at line 324 :
...
function getBindingParameters(module_name, get_prop_map) {
var session_key = '__gwtDevModeSession:' + module_name;
--> var prop_map = get_prop_map(); <--
...
Once the function get_prop_map is called, a few more obfuscated functions run and the debugger returns.
I know it is still experimental, but do you have any idea of what I could have done wrong ?
PS: I am using GWT 2.5, GWT-maven-plugin 2.5 and Chrome 23.0.1271.64 m
We have found a similar issue and tracked down the cause, looks like a boundary case not handled in GWT.
More info can be found here: http://code.google.com/p/google-web-toolkit/issues/detail?id=7894
I don't have an answer, but I can give some general debugging tips for this sort of problem.
Super Dev Mode currently (as of 2.5) doesn't report any progress to the web browser while it's compiling. It won't update the dialog until the compile finishes. So it's possible that it's just very slow for your program for some reason, or the compile stopped and somehow didn't report an error like it normally does.
However, there are other ways you can monitor its progress. The compiler log is available as a web page by following links from the code server's front page; you will have to refresh the page to see updates. Or you could look at the log on disk in the code server's work directory. (You can set the work directory with the -workDir argument when you start it.)
Another way is to start the code server from the command line. Any stack traces from the code server will be printed there. You should also be able to look at the output in Eclipse or IntelliJ if you're running it from there.
From this you should be able to tell whether the compiler is slow, but still working (it's still printing output) or has actually stopped with a stack trace.
Being new to NetBeans 7 (this is running on Windows 7 64-bit Ultimate Edition) I found it extremely interesting that I can't get any POC (proof of concept applications) to be "viewable." Allow me to explain.
Going through the tutorials - about as simple as anything can ever be in software dev:
1) I create may NetBeans Development application ... but using a product location other than the default. NetBeans wants to use C:\Users{user_name}\Documents\NetBeanProjects as the root path to your projects, then create project folders underneath. Reasonable, but I have dedicated "development drives" where all my development happens, which is not where NetBeans wants to put it.
2) Create a Module for the application. Here I created an Installer and placed a System.out.println() in an overriden restored() method .... you never see this in the Output windows of the IDE. I also added a new Window with a button and textArea, and set the new Window's properties to be shown on application startup and in the Editor location .... you never see these either.
Long story short, I uninstalled NetBeans v7.0 from the computer, and reinstalled it again, but this time allowing the IDE to use the location it wants for project folders. Though, I still do not get the System.out.println() text in the Output window, I do get my new Windows with the button and TextArea.
I've added this post because I did a bunch of seaches trying to find an answer to all this to no avail. I certainly don't have the real answer, but if someone else is strugling with the same problem you'll at least have a "partial answer" if you've changed default project locations and your applications "don't seem to run or be visible."
If anyone knows the real answer to these questions PLEASE advise.
EDIT #1 ... thinking this might be a security or privilege issue I tried running the IDE "as Administrator" and this didn't make any difference. I do not see any prompts or anything in the OS' logs that indicate a problem either, so I'm assuming it's NetBeans.
EDIT #2 ... Found it. Finally discovered where all my System.out.println()'s are ending up. Not in the IDE's Output Window as I would have expected (pretty sure I'm not the only one) but in a "message.log" text file located at
C:\Users\{User_Name}\Documents\NetBeansProjects\{Project_Name}\build\testuserdir\var\log
That was fun - Not! I am assuming that this probably means the System.out is currently set to do this in a property somewhere. But at least I know it's not disappearing off into space somewhere now.
re. the System.out "Not in the IDE's Output Window", have you tried to instantiate a logger instead?
Directly after the class declaration, paste in the following field definition:
private static final Logger logger = Logger.getLogger("thePackageName.andYourClassNameHere");
import the import java.util.logging.Logger; library.
then simply log what ever you want to trace on the output console.
ie: logger.info(" ... " + ....);
I am using the Flex Builder 3 debugger almost every day and it's starting to be a real pain that the 'Variables' tab in the 'Flex Debugging' view doesn't show local variables, only 'this' is displayed.
Also I can not add Watch Expressions for local variables.
Am I forgetting something here or is the debugger just very limited?
Thanks
I have the same problem that motto described. Local variables are not displayed when debugging, "hover" method doesn't work either. You can always use trace() or Loging API.
The problem occurred to me yesterday and the only thing I noticed is that the project stopped to compile using ant script due to OutOfMemoryError (I usually build project using FB, but sometimes FlexBuilder doesn't show errors/warnings and compiling via ant script is the only way I know to find them).
To see if Flex Builder is even tracking your local variables properly, set a breakpoint somewhere in a function. Once you hit that breakpoint, you can also "hover" over a variable in your source code, and a tooltip should show the current value of that variable.
Sometimes, FB has problems if the current function is further down in a larger file. Moving the function code up solves the problem (but exposes the same for another funciton further doen then). It seems that FB can only gather a certain amount of metadata for the currently open file.
I'd like to script FlexBuilder so that I can run debug or profile without having to switch to FlexBuilder and manually clicking the button (or using the key combo). Is this possible without writing an extension?
To be more specific, this is exactly what I want to do: I want to create a TextMate command that talks to FlexBuilder and makes it run the debug target for the currently selected project. TextMate already has support for interacting with Xcode in this way, and it would be great to be able to do the same with FlexBuilder.
When compiling I use Ant and have full control over that from TextMate, what I want is to be able to launch the debugger and the profiler. The command line debugger is unusable and there is no other profiler available than the one in FlexBuilder.
Since FlexBuilder essentially is an extended version of Eclipse, any tools/scripts for doing the same in Eclipse should work for FlexBuilder aswell. I couldn't find any tools like this googling it, have you considered doing away with FlexBuilder completely, there are plenty of guides for using the mxmlc (or fcsh) compilers directly from your editor.
I do not know if there is a plugin like this for Eclipse however if not you can write one as it should be easy.
If the specific command that you want to call shows up in Windows/Preferences - General/Keys, you can create a plugin that takes commands from TextMate (I do not know what protocol TextMate uses, socket or something else) and executed the specific action that is associated with the command that also appears in preferences.