How to mark logical sections of code in Java comments?

For intellij/android studio there is an amazing solution.
Start with:
//region Description
and end with:
//endregion

The shortcut for that is in the menu you can open with Command+Alt+T (Mac) or Ctrl+Alt+T (Windows)

You can also add your own line for additional visual separation if you need it. The region can be contracted and expanded at will with the +/- buttons like any function. You can also navigate between regions with Command+Alt+Period (Ctrl+Alt+Period)

Source.

Example:

//region Parceler Implementation
//---------------------------------------------------------------------------------------
@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeParcelable(this.die, 0);
    dest.writeParcelable(this.dieSprite, 0);
}

private DieVm(Parcel in) {
    this.die = in.readParcelable(Die.class.getClassLoader());
    this.dieSprite = in.readParcelable(Sprite.class.getClassLoader());
}

public static final Parcelable.Creator<DieVm> CREATOR = new Parcelable.Creator<DieVm>() {
    public DieVm createFromParcel(Parcel source) {
        return new DieVm(source);
    }

    public DieVm[] newArray(int size) {
        return new DieVm[size];
    }
};
//---------------------------------------------------------------------------------------
//endregion

I personally use 80-chars line separators, like this :

public class Client {

    //================================================================================
    // Properties
    //================================================================================

    private String name;
    private boolean checked;

    //================================================================================
    // Constructors
    //================================================================================

    public Client() {
    }

    public Client(String name, boolean checked) {
        this.name = name;
        this.checked = checked;
    }

    //================================================================================
    // Accessors
    //================================================================================

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public boolean isChecked() {
        return checked;
    }

    public void setChecked(boolean checked) {
        this.checked = checked;
    }

}

Of course, this may seem a bit overkill for such a small POJO, but believe me, it proved very useful in some huge projects where I had to browse through big source files and quickly find the methods I was interested in. It also helps understand the source code structure.

In Eclipse, I have created a set of custom templates (Java -> Editor -> Templates in Eclipse's Preferences dialog) that generate those bars, eg. - sepa (SEParator for Accessors) - sepp (SEParator for Properties) - sepc (SEParator for Constructors) - etc.

I also modified the standard "new class" template (Java -> Code Style -> Code Templates in Eclipse Preferences screen)

Also, there is an old Eclipse plugin called Coffee-bytes, which enhanced the way Eclipse folds portions of code. I don't know if it still works, but I remembed one could define arbitrary foldable zones by adding special comments, like // [SECTION] or something. It might still work in recent Eclipse revisions, so take a look.

Eclipse defines an @category javadoc annotation (scroll to section marked "Category support") which enables filtering by category in the outline view. Not exactly what you want. I'm suprised nobody has written an Eclipse plugin which offers a view like your screen shot.

I liked that also when i was using xcode. For eclipse i use ctrl+o (quick outline) to navigate through a Java class.