Запись данных

   File file = new File(data);
            FileWriter fw = new FileWriter(data);
            fw.write(stroka);
            fw.close();
            XfdfReader fdfreader = new XfdfReader(data);

package memory;
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
 
public class FileInMemo {
 
    public static void main(String[] args) throws IOException {
        StringWriter sw = new StringWriter();
        String stroka = "blablastring";
        sw.write(stroka);
        sw.write(System.getProperty("line.separator"));
        sw.write(stroka);
        sw.write(System.getProperty("line.separator"));
        
        StringReader sr = new StringReader(sw.toString());
        BufferedReader br = new BufferedReader(sr);
        String line;
        while (( line = br.readLine()) != null) {
            System.out.println(line);
        }
        XfdfReader fdfreader = new XfdfReader(sr.toString().getBytes());
// или
        XfdfReader fdfreader = new XfdfReader(sw.toString().getBytes());
    }
 
}

Exception in thread "main" java.io.IOException: Missing end tag near line 1, column 0
    at com.itextpdf.text.xml.simpleparser.SimpleXMLParser.throwException(SimpleXMLParser.java:594)
    at com.itextpdf.text.xml.simpleparser.SimpleXMLParser.go(SimpleXMLParser.java:214)
    at com.itextpdf.text.xml.simpleparser.SimpleXMLParser.parse(SimpleXMLParser.java:607)
    at com.itextpdf.text.xml.simpleparser.SimpleXMLParser.parse(SimpleXMLParser.java:682)
    at com.itextpdf.text.xml.simpleparser.SimpleXMLParser.parse(SimpleXMLParser.java:648)
    at com.itextpdf.text.pdf.XfdfReader.<init>(XfdfReader.java:113)
    at com.itextpdf.text.pdf.XfdfReader.<init>(XfdfReader.java:103)
    at testReadWrite.main(testReadWrite.java:34)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)