treemapexample.java

java2 primer plus一书源程序

import java.util.Set;
import java.util.Map;
import java.util.TreeMap;
import java.util.Iterator;

public class TreeMapExample
{
    public static void main( String[] args )
    {
        // Create a new TreeMap
        Map map = new TreeMap();

        // Add Items to the TreeMap 
        map.put( new Integer( 1 ), "One" );
        map.put( new Integer( 2 ), "Two" );
        map.put( new Integer( 3 ), "Three" );
        map.put( new Integer( 4 ), "Four" );
        map.put( new Integer( 5 ), "Five" );
        map.put( new Integer( 6 ), "Six" );
        map.put( new Integer( 7 ), "Seven" );
        map.put( new Integer( 8 ), "Eight" );
        map.put( new Integer( 9 ), "Nine" );
        map.put( new Integer( 10 ), "Ten" );

        // Use iterator to display the keys and associated values 
        System.out.println( "Map Values Before: " );
        Set keys = map.keySet();
        for( Iterator i=keys.iterator(); i.hasNext(); )
        {
            Integer key = ( Integer )i.next();
            String value = ( String )map.get( key );
            System.out.println( key + " = " + value );
        }

        // Remove the entry with key 6 
        System.out.println( "\nRemove element with key 6" );
        map.remove( new Integer( 6 ) );

        // Use iterator to display the keys and associated values 
        System.out.println( "\nMap Values After: " );
        keys = map.keySet();
        for( Iterator i=keys.iterator(); i.hasNext(); )
        {
            Integer key = ( Integer )i.next();
            String value = ( String )map.get( key );
            System.out.println( key + " = " + value );
        }
    }
}