import java.util.regex.Pattern;
public class Main {
public static void main(String[] argv) throws Exception {
CharSequence inputStr = "a\r\rb"; // Mac
//inputStr = "a\r\n\r\nb"; // Windows
//inputStr = "a\n\nb"; // Unix
String patternStr = "(?<=(\r\n|\r|\n))([ \\t]*$)+";
String[] paras = Pattern.compile(patternStr, Pattern.MULTILINE).split(inputStr);
for (int i = 0; i < paras.length; i++) {
String paragraph = paras[i];
}
}
}