Stop Eclipse from mangling my comments

Go to the "Window" menu -> preferences
choose the editor you're interested in from the list on the left.(e.g. Java)
then there should be a subsection called "Code Style", and under that "Formatter".

Then you'll need to create a new formatter profile. (The built-in profile can't be edited) On the last tab of the profile configuration is options for comment formatting

1. Go to Preferences -> Java -> Code Style -> Formatter
2. There edit the profile and switch to the last tab called "Comments"
3. Uncheck the "Enable line comment formatting"

There is another solution that you can use to suppress the formatting of specific block comments. Use /*- (note the hyphen) at the beginning of the block comment, and the formatting won't be affected if you format the rest of the file.

/*-
 * Here is a block comment with some very special
 * formatting that I want indent(1) to ignore.
 *
 *    one
 *        two
 *            three
 */

Source: http://www.oracle.com/technetwork/java/javase/documentation/codeconventions-141999.html#680

Window->Preferences->Java->Code Style->Formatter. Create new formatter. Click on edit and then pick tab Comments unchecked Enable Line comment formatting and Enable block comment formatting