Eclipse formatter settings for the Builder pattern.

Question

I'm extremely frustrated with the Eclipse formatting rules for a series of qualified invocations (i.e., the Builder pattern style). For example, here is my preferred formatting for some code that creates a new Apache Commons CLI Options object:

  Options options = new Options()
      .addOption(OPTION_HELP_SHORT, OPTION_HELP, false, "print usage information")
      .addOption(OPTION_VERSION_SHORT, OPTION_VERSION, false,
          "print version and exit")
      .addOption(OptionBuilder.withLongOpt(OPTION_PROPERTIES)
                     .hasArg()
                     .withArgName("FILE")
                     .withType(File.class)
                     .withDescription("specify a user properties file")
                     .create());

I.e., parameters are wrapped and indented if necessary and all qualified invocations except the first, unless necessary, are wrapped and indented if there is more than one. If a parameter list wraps inside a qualified invocation, the invocation should wrap first.

The default formatting in Eclipse ("Wrap only when necessary" for arguments and invocations) yields the following mess:

  Options options = new Options().addOption(
      OPTION_HELP_SHORT, OPTION_HELP, false, "print usage information")
      .addOption(OPTION_VERSION_SHORT, OPTION_VERSION, false,
          "print version and exit").addOption(
          OptionBuilder.withLongOpt(OPTION_PROPERTIES).hasArg().withArgName(
              "FILE").withType(File.class).withDescription(
              "specify a user properties file").create());

Going into "Java Code Style -> Formatter -> Line Wrapping" and the line wrapping setting to "Wrap all elements, except first element if not necessary" for invocations yields:

  Options options = new Options().addOption(
      OPTION_HELP_SHORT, OPTION_HELP, false, "print usage information")
      .addOption(OPTION_VERSION_SHORT, OPTION_VERSION, false,
          "print version and exit")
      .addOption(
          OptionBuilder.withLongOpt(OPTION_PROPERTIES).hasArg().withArgName(
              "FILE").withType(File.class).withDescription(
              "specify a user properties file").create());

I don't like that the OptionBuilder expression isn't being wrapped, or that "FILE" gets wrapped without also wrappingwithArgName`.

Changing the indentation to "Indent on column" yields:

  Options options = new Options().addOption(OPTION_HELP_SHORT, OPTION_HELP,
                                     false, "print usage information")
                                 .addOption(OPTION_VERSION_SHORT,
                                     OPTION_VERSION, false,
                                     "print version and exit")
                                 .addOption(
                                     OptionBuilder.withLongOpt(
                                                      OPTION_PROPERTIES)
                                                  .hasArg()
                                                  .withArgName("FILE")
                                                  .withType(File.class)
                                                  .withDescription(
                                                      "specify a user properties file")
                                                  .create());

The is breaking the lines where I'd prefer, but pushing things over much too far to the right.

Is there any way to convince Eclipse to apply my preferred formatting style or something closer to it than any of the above?

Answer 1

On the menu select Window -> Preferences when the window opens select Java -> Code Style -> Formatter and from there you can create your own format style to use by selecting the new or edit option. When editing a formatting profile a new window opens that gives you a lot of different options to use.

Answer 2

Use comments:

   Object o = foo() //
      .bar() //
      .toString();

Answer 3

AFAIK, this is known problem with Eclipse Formatter: https://bugs.eclipse.org/bugs/show_bug.cgi?id=59891

Answer 4

In Eclipse 3.6 It's possible to turn off formatting for a region of code. See my answer to

http://stackoverflow.com/questions/1820908/how-to-turn-off-the-eclipse-code-formatter-for-certain-sections-of-java-code/