Eclipse Formatter isn't indenting correctly

Question

We are using the Java Conventions [built-in] formatter for our Eclipse projects. The code looks as expected after formatting and indents correctly when viewing it in Eclipse.

What we've noticed is that if we open the file in Notepad++ (Or other apps) the indentation is actually incorrect. E.g. The method body has the same indentation as the method. Also if code is copied from Eclipse it isn't indented correctly.

Example 1

In Eclipse

class Example {

    public static void main(String args[]) {
        System.out.println("Hello World!");
    }
}

In Notepad++

class Example {

public static void main(String args[]) {
    System.out.println("Hello World!");
}
}

Example 2

In Eclipse

public static void main(String args[]) {
    System.out.println("Hello World!");
}

In Notepad++

public static void main(String args[]) {
System.out.println("Hello World!");
}

Is this behaviour expected?

Screenshot of spaces/tabs

All Characters

Answer 1

The default Eclipse formatter profile, Eclipse [Built-in], displays tabs with a width of 4 spaces.

In contrast, the Java Conventions [Built-in], displays tabs with a width of 8 spaces.

This is given by the Code Conventions for the Java Programming Language, 4 - Indentation as follows (highlighting by me):

Four spaces should be used as the unit of indentation. The exact construction of the indentation (spaces vs. tabs) is unspecified. Tabs must be set exactly every 8 spaces (not 4).

These days, the original Java Code Conventions with its mixed tab policy and a tab width of 8 spaces is rarely used. You may consider switching to the Eclipse [Built-in] formatter profile.

Answer 2

The Java Conventions [Built-in] profile uses 8 spaces for tabs.

Notepad uses 8 spaces but Notepad++ (and most other IDEs I've used E.g. IntelliJ) uses 4 spaces.

To fix this copy the profile and change the tab spacing to 4.

Alternatively the Tab Policy could be changed to Spaces Only. I prefer this as I don't feel tabs should be used for spacing. This question is an example of why tabs shouldn't be used.