50 slides of IDE — Eclipse Con France 2015

Baptiste Mathus
batmat@batmat.net

About Me

avatar baptiste

Baptiste Mathus

MojoHaus Committer (previously MOJO@Codehaus)

Jenkins Contributor & Plugins Maintainer

#automation #tooling #java #passion #oss #jenkins #maven #nexus #sonarqube

Preamble

  • You will already know some of the tricks here.
  • Some may even appear obvious ; for you.

  • Just wait for the next one then, it should not be long.

    • 50 tips ⇒ 35 minutes ⇒ 42 (!) seconds per tip!

Don’t worry: slides with each tip will be provided

First one: make saving things easier (and quicker lol) than clicking in the typical place where you usually find it in applications.

CTRL-S (Yay!)

This one is very useful. And alternatively you can also click (with the mouse) on the small icon that you will generally find on the left (because this is actually customisable, I’ve been told). I like it because it prevents you from going into the File/Save Menu. It took me years to find this one. I hope you will enjoy it too!

I hope you will like it as much as I did. I hope.

Lol…​

Let’s go

Let’s now get a bit more serious, only 34 minutes left…​

(1/51) Abreviate package name

In Java/Appearance/abbreviate package names :

Example:

net.batmat.econ2015={DEMO}

Before

After
pkg abbreviation before
pkg abbreviation after

(2/51) Find any class by name

Control-Shift-T

(3/51) Browse current class methods

Ctrl-O displays all the methods of the current class

Or Inherited

Ctrl-O-O methods of the current class + parent

(4/51) Find resources

Control-Shift-R

(5/51) Use CamelCase

camelcase filtering

Or more selectively

camelcase filtering more selective

Use space or < to stop matching

(6/51) Move/Copy lines up and down

  • Alt-arrow-down to move the currently selected lines down
  • Ctrl-Alt-arrow-down to copy the currently selected lines down

(7/51) Quick contextual execution menu

Alt-Shift-x will display a contextual menu.

Example: you’re in a JUnit class, just type Alt-Shift-X then T to run the tests.

alt shift x menu

(8/51) Execute previous run instead of current open file

Be explicit. Changing the code it’s natural to just run Ctrl-F11 or F11 to re-execute the previously ran test

Run/Debug/Launching/Launch Operation/Always launch the previously launched application

(9/51) Quick fix

Type Ctrl-Shift-1 (or click on the lightbulb on the left of the line) to see what the possible actions are on the current focus

Quick Fix Example

(10/51) Extract Method

Select text, right click and extract the whole code block into a new method easily.

Inverse: see (11/51) Inline Method

(11/51) Inline Method

Easily inline the code of a method.

  • Select method to inline/Right click/Refactor/Inline Method.
  • Shortcut: Alt-Shift-I

Inverse: see (10/51) Extract Method

(12/51) Refactoring: Replacing ternary with if-else

Replace your ternary expression with an if-else (more often than not!)

Before :

ternary before

After :

ternary after

(13/51) Invert if/else conditions

Select the if/else to invert, and call the Quick Fix

(14/51) Generate for-loop on collection or array

Just type the collection/array, and call the Quick Fix

(15/51) Finding matching curly braces

If putting your cursor next to the curly brace isn’t enough to find the associated closing/opening one:

Use Ctrl-Shift-P

(16/51) Convert to lambda expression

Accessible through Clean Up & Quick Fix

(17/51) Typing: automatically place semicolons

(18/51) Typing: escape text when pasting into a string literal

Not enabled by default. In Java/Editor/Typing.

(19/51) Meta-Shortcut

Use Ctrl-Shift-3 on a selected item, then start typing to filter the possible actions in the Quick access menu.

(20/51) Save actions: automatic formating

Useful: be able to automatically format only the code just modified when saving the file.

See in Java/Editor/Save Actions/Format source code/Format edited lines

(21/51) Formatter: don’t touch that part (using begin/end tags)

// @formatter:off
     // Some weirdly formatted source
     String s2 =
				            "hello";
// @formatter:on

Thanks Emmanuel Fontan

(22/51) Formatter: format selectively

Select the text you want to format, and hit ctrl-shift-f as usual.

(23/51) Tweak autocompletion (aka content assist)

Typing Ctrl-Space many times shows different proposals.

contentassist tuning

Those are actually configurable (list and order of proposals).

See Java/Editor/Content Assist/Advanced.

(24/51) Favorites

Autocomplete static imports!

In Java/Editor/Content Assist/Favorites

(25/51) JSR305 annotations to help null analysis

Lets you add more typesafe-ness in your codebase (at least way more than Javadoc does!).

Beware: it’s not enforcing anything at all at runtime. This is only hints for the developer.

To go even further:

(26/51) Null analysis: one step further with Type Annotations (JSR 308)

@Nonnull List<@Nonnull String> list = new ArrayList<>();

for(String string : list) {
  if(string != null )	{ // Useless if hinted by Eclipse
    throw new IllegalArgumentException("WTF?");
  }
  ...
}

(27/51) Annotating the package itself

Advice: annotate the package itself to define the default value for a whole package

⇒ package-info.java

Note
 With regards to Null Analysis : because studies show developers actually expect parameters to be passed non null as a default, you will generally annotate the package with "Nonnull by default" and then only annotate methods where you actually expect or produce Nullable things.

(28/51) Overwrite end of method name instead of adding

Java/Editor/Content Assist : toggle "Completion overwrites" instead of "Completion Inserts"

Can be live toggled using Ctrl key.

(29/51) Instanceof Automatic Contextualization

Inside an instanceof block, analyzes the type of the given instanceof and autocompletes with its methods:

autocast instanceof

(30/51) Type filters

In Java/Appearance/Type Filters

To filter out java.awt.* for example…​

Filter out method coming from Object! (who wants to call notify()…​)

type filters

(31/51) Filtering methods by categorizing them

Categorize Filtering/choosing which methods to display in the Outline using javadoc’s @category tags

(thanks Jordi Barrère).

(32/51) Step filtering

Be able to filter out stack when debugging:

  • By class
  • Constructors
  • Getters/setters
  • …​

Thanks Sebastien Bordes for the reminder

(33/51) Multi-line Edit

Alt-Shift-A or the icon, as if Sublime Text invented it all ;-)

(Thanks Olivier Jaquemet)

(34/51) Logical structure

Present complex/weird physical data structure in a logical way in the debugger

For reference see the official documentation or that forum discussion.

(35/51) Switch between tabs

  • Ctrl-E : displays a full list
  • Ctrl-F6 : Alt-tab for Eclipse
  • Ctrl-Page Up/Down : easily switch between tabs

(36/51) Full screen the current view

Ctrl-M

(37/51) Remove the lines with the cursor/selection

Ctrl-D

(38/51) Working Sets

Useful to categorize projects, or packages.

(39/51) Scrapbooking, REPL

String s = String.format("%05d", 7);
s

https://recoveringprogrammer.wordpress.com/2013/04/06/using-eclipse-scrapbook-to-quickly-test-your-code/

(40/51) Add to snippets

You can easily add any code block for future reuse.

(41/51) Code templates

Difference with snippets: can be variabilized.

Cf. Java/Editor/Templates

Example: JDK8 foreach
${iterable}.forEach(${iterable_element} -> {
	${cursor}
});

Thanks Vincent!

(42/51) Extensions: SnipMatch

Example: formatter on/off (cf. (21/51) Formatter: don’t touch that part (using begin/end tags))

(43/51) Breakpointing

  • Conditionally
  • by Hit Count
  • By Exception Type
  • By Class Loading
breakpointing

(44/51) Conditional breakpoint

Many conditions, not always well-known

Use it to debug :

System.out.println("HERE WE ARE: "+theVariable);
return false;

Gotcha: in external jars (like rt.jar) without local variable table, use the arg0, arg1…​ placeholders for parameters, instead of the original parameter names.

(45/51) Debugging: Run to line

When debugging, you don’t have to put a breakpoint on some line to take the debugger up to it.

Just put the cursor on the line you want, then Ctrl-R (or right click/Run to line)

Thanks Olivier :-)

(46/51) Debugging: Drop To Frame

http://eclipsesource.com/blogs/2013/01/08/effective-java-debugging-with-eclipse/

(47/51) Clean Up

(48/51) How to quick fix many issues outside of the Clean up menu

Many quick fixes are actually available, but not always through cleanup

  • Go to the Problems view
  • Then call…​ the Quick Fix
  • Select the issue you want to fix
  • Click select all

Possible since Luna SR2

(49/51) JSR 305 externally defined annotations

Complementary to (25/51) JSR305 annotations to help null analysis

New in Eclipse Mars, released yesterday! (24/03/2015).

See JSR305 externally annotated classes (Eclipse Mars)

(50/51) Workspace name

Useful if you often switch between workspaces.

Under General/Workspace, you can set the workspace name field.

(51/51) Using Docker to build a clean Eclipse with wanted features

Dockerfile
FROM ndeloof/java

MAINTAINER Baptiste Mathus <batmat@batmat.net>

RUN curl http://ftp.halifax.rwth-aachen.de/eclipse//technology/epp/downloads/release/mars/R/eclipse-java-mars-R-linux-gtk-x86_64.tar.gz | tar -xvz

WORKDIR /eclipse

RUN ./eclipse -nosplash -application org.eclipse.equinox.p2.director \
              -repository http://download.eclipse.org/releases/mars \
              -installIUs org.eclipse.egit.feature.group,org.eclipse.jgit.feature.group

RUN ./eclipse -nosplash -application org.eclipse.equinox.p2.director \
              -repository http://download.eclipse.org/releases/mars \
              -installIUs org.eclipse.m2e.feature.feature.group

CMD ["cp","-R","/eclipse","/eclipse-provisioned"]

Acknowlegments

  • Thanks to the ToulouseJug community for providing some of the tips here

Questions?

Don’t forget to evaluate the session

evaluate slide 4 3
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