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