(Former) IntelliJ Notes

Here's how to turn line numbers on permanently and remove vertical indent guides (those annoying vertical lines in the editor).

1. File -> Settings....
2. Look down the left pane for IDE Settings -> Editor.
3. Look for Appearance.

1. Look to bottom of workbench, click on Changes.
2. Right-click on Default or the file you wish to see.
3. Choose Show Diff.

Symptom

A class is missing even when the import statement is typed in by hand (and valid).

Analysis

The JAR containing the class is missing (duh).

Solution

The JAR must be included in the module's pom.xml. The JAR may be known to other modules in the project. Here's how to add it to the current module where it's missing:

1. Figure out which JAR supplies the missing symbol:
   1. Right-click the project root—that is, the top-level project (and not the module missing the symbol).
   2. Choose Find in Path and narro the search to pom.xml files.
   3. Choose a good occurrence in the resulting search output list.
   4. Copy the whole dependency.
2. Open pom.xml (in the module missing the JAR/symbol) and paste in the new dependency clause.
3. Open Maven Projects view (right-hand margin of IntelliJ workbench) and click the reload button (circling arrows at upper-left of view).

Note that a module may not be missing the symbol and yet not define the dependency because it inherits dependencies from the project (root) pom.xml as long as it defines none of its own.

IntelliJ loves to corrupt import statements by collapsing like package names down and discarding all the classnames in favor of using a wildcard (*). To turn this off, I apparently had to set the number of imports up to 99 in:

File -> Settings -> Code Style -> Java -> Class count to use import with '*'
                                                      Names count to use static import with '*'

Hovering over a method will not, as in Eclipse, tell you anything about it. Instead, holding down the Ctrl key and hovering will tell you or hovering and pressing Ctrl-Q will get you the Javadoc.

Here's how to attach sources in IntelliJ. This is one thing that's easier and more successful in IntelliJ than in Eclipse.

1. Click link Attach Sources.
2. In the Attach Sources dialog, navigate to the root of the project containing the source code, e.g.: project ct.
3. Click OK.
4. See "Scanning for roots"; choose a root or, for all source code, click OK (since all are selected).
5. Enjoy population of editor window with source code.