Name: akC57697 Date: 12/08/97


 The java.awt.swing.JTable indexOfTab does not work properly with null.


The documentation says:
    /**
     * Adds a <i>component</i> represented by a <i>title</b> and no icon.
     * Cover method for insertTab().
     * @see #insertTab
     */
    public void addTab(String title, Component component)
    
    /**
     * Inserts a <i>component</i>, at <i>index</i>, represented by a
     * <i>title</i> and/or <i>icon</i>, either of which may be null.
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     * Uses java.util.Vector internally, see insertElementAt()
     * for details of insertion conventions.
     * @param component The component to be displayed when this tab is clicked.
     */
    public void insertTab(String title, Icon icon, Component component, String tip, int index)


    /**
     * Convenience method for locating the first tab with a given <i>title</i>,
     * testing for equality with String.equals. Returns -1 if no tab has this title.
     */
    public int indexOfTab(String title)




The linear search with invoking String.equals without checking for null is
the reason of this bug.




 --------------8-<-----------------------------------
import java.awt.swing.JTabbedPane;
import java.awt.Component;

public class JTabbedPaneBug {
    public static void main(String s[]) {

 Component components [] ={new JTabbedPane(),new JTabbedPane(),new JTabbedPane()};
 String names [] ={"1",null,"3"};
 int result=0;

      JTabbedPane c = new JTabbedPane();

      for(int j=0;j<components.length;j++)
        c.addTab(names[j],components[j]); //Fill the set

      try {
         result=c.indexOfTab("3"); //Try to find "3" through the null
       } catch (Exception e) {
          System.out.println("Unexpected in indexOfTab() : "+e);
         }
      
      System.exit(0);
   }
}

 --------------8-<-----------------------------------
 The output is:
(novo35 46): java JTabbedPaneBug
Unexpected in indexOfTab() : java.lang.NullPointerException
(novo35 47): java -fullversion
java full version "JDK-1.2beta2-Y"

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