今気づいたんですけど、最初にうまくいったときは、ターミナル上にdouble型で入力されたのがでていました。
ですが、SetDataがでないときはこうゆうのがでます。
apple.awt.EventQueueExceptionHandler Caught Throwable :
java.lang.NumberFormatException: empty String
at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:986)
at java.lang.Double.parseDouble(Double.java:202)
at FrameForm.actionPerformed(FrameMain.java:67)
at java.awt.Button.processActionEvent(Button.java:381)
at java.awt.Button.processEvent(Button.java:350)
at java.awt.Component.dispatchEventImpl(Component.java:3598)
at java.awt.Component.dispatchEvent(Component.java:3439)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:450)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:230)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:177)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:99)