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

Issue

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
}

Solution

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:

1. Window > Preferences > Java > Code Style > Formatter
2. Click Edit
3. Select the Line Wrapping tab
4. Select the enum declaration treenode
5. Set Line wrapping policy to Wrap all elements, every element on a new line (...) so it now says 3 of 3 in the parenthesis.
6. Uncheck Force split, even if line shorter than maximum line width (...) so it now says 3 of 3 in the parenthesis.
7. Select the Constants treenode
8. 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)
}

Answered By - PolyTekPatrick