Index: src/main/java/common/javax/swing/JScrollBar.java =================================================================== --- src/main/java/common/javax/swing/JScrollBar.java (revision 490131) +++ src/main/java/common/javax/swing/JScrollBar.java (working copy) @@ -120,6 +120,11 @@ public JScrollBar(final int orientation, final int value, final int extent, final int min, final int max) { model = new DefaultBoundedRangeModel(value, extent, min, max); + + if (orientation != HORIZONTAL && orientation != VERTICAL) { + throw new IllegalArgumentException("Orientation is not HORIZONTAL or VERTICAL"); + } + this.orientation = orientation; blockIncrement = extent;