the spec states:

public String[][] getZoneStrings()
...
The value returned is a two-dimensional array of strings of size n by m, where m is at least 5.

a test text:
--------------------
import java.text.DateFormatSymbols;

public class Test {

    public static void main( String[] args ){
        DateFormatSymbols obj = new DateFormatSymbols();
        String[][] zs = {
            { "GMT", "AA", "BB" }
        };

        obj.setZoneStrings(zs);

        for( String[] s : obj.getZoneStrings() ){
            if( s.length < 5 ){
                System.out.println( "m = " + s.length );
                System.out.println( "specification violation:\nThe value returned is a two-dimensional array of strings of size n by m, where m is at least 5." );
                return;
            }
        }
        System.out.println("OK");
    }
}
--------------------

There are at least 3 ways to solve this problem:
- to throw IllegalArgumentException in setZoneStrings()
- appropriately modify array passed in setZoneStrings() before returning from getZoneStrings()
- to change the spec