The general sorting program

In the previous chapter, we implemented a simple sort algorithm. The code can sort elements of a String array. We did this to learn. For practical use, there is a ready cooked sort solution in the JDK that can sort members of collections, which are comparable.

The JDK contains a utility class called Collections. This class contains a static Collections.sort method that is capable of sorting any List that has members that are Comparable. List and Comparable are interfaces defined in the JDK. Thus, if we want to sort a list of Strings, the simplest solution is as follows:

public class SimplestStringListSortTest { 
    @Test 
    public void canSortStrings() { 
        ArrayList actualNames = new ArrayList(Arrays.asList( 
                "Johnson", "Wilson", 
                "Wilkinson", "Abraham", "Dagobert" 
        )); 
        Collections.sort(actualNames); 
        Assert.assertEquals(new ArrayList<String>(Arrays.<String>asList( 
                "Abraham...