Tables - The Definitive Guide to Java Swing - page 692

// Check for nulls
Object o1 = data.getValueAt(row1, column);
Object o2 = data.getValueAt(row2, column);
// If both values are null return 0
if (o1 == null && o2 == null) {
return 0;
} else if (o1 == null) { // Define null less than everything.
return -1;
} else if (o2 == null) {
return 1;
}
if (type.getSuperclass() == Number.class) {
Number n1 = (Number)data.getValueAt(row1, column);
double d1 = n1.doubleValue();
Number n2 = (Number)data.getValueAt(row2, column);
double d2 = n2.doubleValue();
if (d1 < d2)
return -1;
else if (d1 > d2)
return 1;
else
return 0;
} else if (type == String.class) {
String s1 = (String)data.getValueAt(row1, column);
String s2 = (String)data.getValueAt(row2, column);
int result = s1.compareTo(s2);
if (result < 0)
return -1;
else if (result > 0)
return 1;
else
return 0;
} else if (type == java.util.Date.class) {
Date d1 = (Date)data.getValueAt(row1, column);
long n1 = d1.getTime();
Date d2 = (Date)data.getValueAt(row2, column);
long n2 = d2.getTime();
if (n1 < n2)
return -1;
else if (n1 > n2)
return 1;