STEPS TO FOLLOW TO REPRODUCE THE PROBLEM : Run attached test. sizeChanged () returns true if componentInnards is null without initializing the object (see line 949). you need to get the value in the FileReader class, and send it as a parameter to the FileListener class.
NULLPOINTEREXCEPTION JAVA NEW FLOWLAYOUT FULL
tHorizontalTextPosition(SwingConstants.CENTER) FULL PRODUCT VERSION : 1.6.014 A DESCRIPTION OF THE PROBLEM : updateSizes () assumes componentInnards is not null (see comment line 465, it says only call after sizeChanged ()). nullpointerexception: you are selecting your value in the FileReader class, but your FileListener class is trying to select it from the one in there, in which you haven't select anything.
tText("Label with icon and text at bottom") Label2 = new JLabel("Label with text and icon",bug,SwingConstants.LEFT) Icon bug = new ImageIcon(getClass().getResource("bug.gif")) When a container size is changed (eg, when a window is resized), FlowLayout recomputes new positions for all components subject to these constraints. At first i thought it was because I didn't have an image called bug1.gif in the same folder as my java files however that was not the case.Įxception in thread "main" Īt .(init)(ImageIcon.java:167)Īt LabelTest.main(LabelTest.java:7) import arranges components from left-to-right and top-to-bottom, centering components horizontally with a five pixel gap between them. Most of the other programs worked perfectly this is the only one iv had a problem with so far. When I copied this example program out of the book I get a null pointer exception.
Hello folks, I recently started learning Java and bought a book to look at some examples. You get NullPointerExceptions and if you follow the exception trace I believe you will find that one of those lines is the guilty one: Icon bug1 new ImageIcon( getClass().getResource( 'bug1.gif' )) Icon bug2 new ImageIcon( getClass().getResource( 'bug2. Example Where Described Notes FlowLayoutDemo: This page: Sets up a content pane to use FlowLayout.If you set the RIGHTTOLEFT constant to true and recompile, you can see how FlowLayout handles a container that has a right-to-left component orientation.
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