public class SplitString {
public static void main(String[] args) {

String context="sasdacont###page###extasdsaas###page###ddsaasdasd###page###saasdsasdadsadsa2131";

String[] subString = context.split("###page###");

int pageFlagNum = subString.length-1;

public class Test {
public static void main(String[] args) {
List list = new ArrayList();
String context = "ss###page###ggggg###page###ffferfawe###page###ssa";
String[] numCut = context.split("###page###");
for (String item: numCut) {
list.add(item);
System.out.println(item);
}