import java.util.regex.*;
import java.lang.*;
 
class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
String str = "Now you will see the following links for the items:\n" +
    	"1111 leading 4 digits and then some text\n" +
		"2565 leading 4 digits and then some text\n" +
		"8978 leading 4 digits and then some text\n" +
		"foo\n" +
		"bar";
Pattern p = Pattern.compile("(?m)^.*?(\\r?\\n)(?:^\\d{4}\\s.*?\\1)+");    
Matcher m = p.matcher(str);
if (m.find())
System.out.printf("Matched: %s%n", m.group(0));
 
	}
}

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