I created a Vector called lines that stores the coordinate points of the end points of drawn line. It accomplishes the task that I want by drawing lines from the stored coordinates but produces the following exception:
Exception in thread "AWT-EventQueue-1" java.lang.ArrayIndexOutOfBoundsException: Array index out of range: 10
at java.util.Vector.get(Vector.java:748)
at DrawPad.paint(DrawPad.java:149)
at java.awt.Container.update(Container.java:1995)
at sun.awt.RepaintArea.updateComponent(RepaintArea.java:255)
at sun.awt.RepaintArea.paint(RepaintArea.java:232)
at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:358)
at java.awt.Component.dispatchEventImpl(Component.java:4967)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
You need to check to see if the element exists before calling lines.get(i). Also, use lines.size() instead of lines.capacity().
for(int i = 0; i < lines.size(); i += 4)
{
if((i+3) < lines.size())
{
g.drawLine(lines.get(i), lines.get(i + 1), lines.get(i + 2), lines.get(i + 3));
}
}