How to stop Eclipse formatter from placing all enums on one line

Question

I have enums like:

public static enum Command
{
login,
register,
logout,
newMessage
}

When formatting the file, the output becomes:

public static enum Command 
{
login, register, logout, newMessage
}

Is there any variable in external formatter (org.eclipse.jdt.core.formatter......) to enforce each enum variable in a separate line? — Paramesh Korrakuti, Oct 04 '18 at 23:54

score 210 · Accepted Answer · edited Nov 25 '14 at 13:36

The answer by @wjans worked fine for normal enums, but not for enums with arguments. To expand on his answer a bit, here's the settings that provided the most sensible formatting for me in Eclipse Juno:

Window > Preferences > Java > Code Style > Formatter
Click Edit
Select the Line Wrapping tab
Select the enum declaration treenode
Set Line wrapping policy to Wrap all elements, every element on a new line (...) so it now says 3 of 3 in the parenthesis.
Uncheck Force split, even if line shorter than maximum line width (...) so it now says 3 of 3 in the parenthesis.
Select the Constants treenode
Check Force split, even if line shorter than maximum line width

This sets the 3 subnodes for the enum treenode to the same wrapping policy, and the same force split policy except for the Constants treenode, so your enums with arguments will be formatted each on their own line. The arguments will only wrap if they exceed maximum line width.

Examples:

@wjans

enum Example {
    CANCELLED,
    RUNNING,
    WAITING,
    FINISHED
}

enum Example {
    GREEN(
        0,
        255,
        0),
    RED(
        255,
        0,
        0)
}

Solution described above:

enum Example {
    CANCELLED,
    RUNNING,
    WAITING,
    FINISHED
}

enum Example {
    GREEN(0, 255, 0),
    RED(255, 0, 0)
}

Still looks wrong in the eclipse previewer for me but when I tried it on the actual source it worked like a charm. Thanks. — Ben Thurley, Oct 11 '13 at 11:53
Thank you, could you post the corresponding XML markup from a eclipse-codeformatter.xml? — Tob, Feb 16 '22 at 10:39

score 51 · Answer 2 · edited Jul 14 '11 at 23:24

51

You can specify this in your formatter preferences:

Preferences: Java -- Code Style -- Formatter
Click Edit
Select the 'Line Wrapping' tab
Select 'enum' declaration -> Constants in the box on the left
Set Line wrapping policy to 'Wrap all elements, every element on a new line'
Check 'Force split...'

edited Jul 14 '11 at 23:24

Manbeardo

544
4
7

answered Jul 13 '11 at 08:47

wjans

10,009
5
32
43

I had this problem for months. The thing I didn't try was "force split". Not sure why it should be needed as you'd think "wrap all elements" would actually wrap all elements! Thanks for the solution. – LegendLength Jun 28 '17 at 10:17

score 11 · Answer 3 · answered Jul 13 '11 at 08:57

It's slightly ugly too, but if your company policy prevents you from changing the formatter, you can just put comments at the end of lines you don't want to be wrapped.

public static enum Command 
{
    login,//
    register,//
    logout,//
    newMessage//
};

pillingworth · Answer 4 · 2015-04-22T14:53:00.727

6

It's not nice but you can turn the Eclipse formatter off for some sections of code...

// @formatter:off
public static enum Command {
    login,
    register,
    logout,
    newMessage
};
// @formatter:on

the option is in the Windows->Preferences->Java->Code Style->Formatter->Edit->Off/On Tags panel

edited Apr 22 '15 at 14:53

answered Jul 13 '11 at 08:53

pillingworth

3,238
2
24
49

1

This works...kind of. The compiler now thinks its an error. Putting them in comments overcomes this problem like // @formatter:off – Bob Kuhar Jan 11 '12 at 21:46

score 4 · Answer 5 · answered Jul 13 '11 at 08:53

4

You need to set the line wrapping policy under enum declaration for "Constants."

Set the wrapping policy to

Wrap all elements, every element on a new line

AND

Check the box that says "Force Split, even if line shorter than,,,,,

answered Jul 13 '11 at 08:53

Ray Toal

86,166
18
182
232

score 2 · Answer 6 · answered Nov 30 '18 at 10:29

Just adding latest Eclipse 2018.9

Window > Preferences > Java > Code Style > Formatter - Edit
Expand Line Wrapping tree node.
Expand Wrapping settings
Expand 'enum' declaration
Edit Constants and Constant arguments.

Constants need to be Wrap all elements, every element on a new line. Constant arguments need to be Wrap where necessary.

score 0 · Answer 7 · answered Jul 15 '23 at 21:01

in my case set org.eclipse.jdt.core.formatter.alignment_for_enum_constants to 17 works with maven formatter plugin: https://code.revelc.net/formatter-maven-plugin/

    <setting
      id="org.eclipse.jdt.core.formatter.alignment_for_enum_constants"
      value="17"
    />

https://gitlab.inria.fr/stopcovid19/submission-code-server/-/blob/develop/.etc/eclipse-formatter-java.xml

How to stop Eclipse formatter from placing all enums on one line

7 Answers7

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