The superclass “javax.servlet.http.HttpServlet” was not found on the Java Build Path
I have a project created by Maven integration in Eclipse. All work fine, but in the work space in all JSP files have this: To the first string where place: When I create a basic dynamic web project and JSP in – all is fine, no errors.
Psql could not connect to server: No such file or directory, 5432 error?
I’ve had this same issue, related to the configuration of my pg_hba.conf file (located in /etc/postgresql/9.6/main). Please note that 9.6 is the postgresql version I am using. The error itself is related to a misconfiguration of postgresql, which causes the server to crash before it starts. I would suggest following these instructions: Certify that postgresql service … Read more
No module named MySQLdb
I am using Python version 2.5.4 and install MySQL version 5.0 and Django. Django is working fine with Python, but not MySQL. I am using it in Windows Vista.
java – invalid method declaration; return type required [duplicate]
On a Java OOP project I got three errors on my constructor: .\Voter.java:14: error: invalid method declaration; return type required .\Candidates.java:7: error: invalid method declaration; return type required .\Candidates.java:14: error: invalid method declaration; return type required codes for constructor: i declared my constructors like this: Anything I missed?
NameError: global name ‘xrange’ is not defined in Python 3
You are trying to run a Python 2 codebase with Python 3. xrange() was renamed to range() in Python 3. Run the game with Python 2 instead. Don’t try to port it unless you know what you are doing, most likely there will be more problems beyond xrange() vs. range(). For the record, what you are seeing is not a syntax error … Read more
Can’t create handler inside thread that has not called Looper.prepare()
You’re calling it from a worker thread. You need to call Toast.makeText() (and most other functions dealing with the UI) from within the main thread. You could use a handler, for example. Look up Communicating with the UI Thread in the documentation. In a nutshell: Other options: You could use Activity.runOnUiThread(). Straightforward if you have an Activity: You could also post … Read more
ImportError: No module named PIL
On some installs of PIL, you must do instead of import PIL (PIL is in fact not always imported this way). Since import Image works for you, this means that you have in fact installed PIL. Having a different name for the library and the Python module is unusual, but this is what was chosen for (some versions of) … Read more
rmarkdown error “attempt to use zero-length variable name”
Putting this as an answer for visibility: this happens if you try to run by selecting all in the Rmd and pressing enter like you would with a normal R script. RStudio tries to run this all as R code, including the markdown parts, leading to the errors you saw. You can avoid this by … Read more
Warning comparison between pointer and integer
It should be In C, simple quotes delimit a single character whereas double quotes are for strings.