Technical Tips & Troubleshooting
I messed up my Eclipse and it doesn’t show all the things it used to show.
First, make sure you are in the Java perspective: in the top right corner of the window, click the Open Perspective toolbar button and select Java.
If your Java perspective doesn’t look right, go to Window → Reset Perspective to return to the Eclipse defaults.
I can’t log in to a 6.031 web site.
Look for the hostname below…
I can’t log in to: 6031.mit.edu, caesar.csail.mit.edu, didit.csail.mit.edu, gitstream.csail.mit.edu, javatutor.csail.mit.edu, omni.csail.mit.edu
These sites require certificates.
First just try restarting your browser, so that the web server asks you to present your certificate again. That often fixes a temporary hiccup.
Next check whether your MIT certificate is valid using the certificate test page.
Then try a different web browser: Chrome, Firefox, Safari. You may have to install your certificate in the new browser.
Are you using Windows with an antivirus checker turned on?
Sometimes antivirus interferes with SSL connections and causes SSL_PROTOCOL_ERROR in every browser.
Try turning off your antivirus checking temporarily to see if it fixes the problem.
If so, then look for a way to add the web server to a whitelist in your antivirus configuration.
I can’t log in to: clicker.csail.mit.edu, constellation.csail.mit.edu, shimmer.csail.mit.edu
These sites use Touchstone.
Please post privately on Piazza and include the URL you tried to visit, whether you were able to log in with 2-factor authentication, and any error information.
Navigating in Eclipse
When I see the name of a variable or method or class in Eclipse, how can I jump straight to its definition?
Command-click (Mac) or Control-click (Windows/Linux) on the name, and Eclipse will jump to its definition.
After a jump like that, how can I go back to where I was before?
Navigate → Back, which might have the keyboard shortcut Alt ⟵ or Command [.
How can I search for a file or a class by name?
Navigate → Open Resource brings up a dialog for quickly searching for and jumping to a file, which is a resource in Eclipse terminology.
Its keyboard shortcut is Command-Shift-R or Control-Shift-R.
Editing in Eclipse
How can I easily rename a variable or method or class?
Put your cursor on the name and use Refactor → Rename (or its keyboard shortcut) to rename that variable, method, or class in all the places it appears.
How can I automatically reformat and reindent my code?
Use Source → Format to clean up your act.
How can I replace tab characters with spaces?
After you have set up Eclipse, Source → Format will change any tabs you have lying around into spaces. You can right-click the package to de-tab all of your classes at once.
How can I easily comment and uncomment parts of my code?
Use Source → Toggle Comment to quickly toggle on or off some lines of code.
The keyboard shortcut is Command / or Control /.
How can I get Eclipse to manage the package import statements automatically?
Use Source → Organize Imports to automatically add and organize Java import statements.
Just start using a new class, Organize Imports, and you’re good to go.
The keyboard shortcut is Command-Shift-O or Control-Shift-O.