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Archive for May, 2009

Read and write a Properties file

May 21, 2009 Leave a comment

// Read properties file.
Properties prop = new Properties();

try {
prop.load(new FileInputStream("filename.properties"));
} catch (IOException e) {
}


// Write properties file.
try {
prop.store(new FileOutputStream("filename.properties"), null);
} catch (IOException e) {
}


Categories: Uncategorized

How do I sort items in a Set?

May 5, 2009 Leave a comment

The trick to sort a java.util.Set is to use the implementation of a java.util.SortedSet such as the java.util.TreeSet class. The example below shows you the result of using the java.util.TreeSet class, in which the items in it will be sorted based on the element’s natural order.

 
package com.corelabs.example.util;

import java.util.Set;
import java.util.TreeSet;

public class TreeSetDemo {
    public static void main(String[] args) {

        // The TreeSet class is an implementation of a SortedSet, this means
        // that when your are using the TreeSet to store you data collections
        // you'll get the items ordered base on its elements natural order.

        Set<String> set = new TreeSet<String>();
        // In the example below we add some letters to the TreeSet, this mean
        // that the alphabets will be ordered based on the alphabet order
        // whichs is from A to Z.
        //
        set.add("Z");
        set.add("A");
        set.add("F");
        set.add("B");
        set.add("H");
        set.add("X");
        set.add("N");

        for (String item : set) {
            System.out.print(item + " ");
        }
    }
}

This demo prints:

A B F H N X Z
Categories: Java