String content = new Scanner(new File("filename")).useDelimiter("\Z").next();
System.out.println(content);

FileInputStream fisTargetFile = new FileInputStream(new File("test.txt"));

String targetFileStr = IOUtils.toString(fisTargetFile, "UTF-8");

String content = new Scanner(new File("filename")).useDelimiter("\Z").next();
System.out.println(content);

final String CHARSET = "UTF-8";
final String DELIMITER = "Some text that is unlikely to occur in the file";
File file = new File("filename")
Scanner scanner = new Scanner(file,CHARSET).useDelimiter(DELIMITER);
String content = null;
if (scanner.hasNext())
    content = scanner.next();
if (scanner.hasNext())
    throw new IllegalStateException("DELIMITER occurs in file. Use a different delimiter");
if (file.length() != content.getBytes(CHARSET).length)
    throw new IllegalStateException("Inconsistent file lengths. Probably a charset related problem.");
System.out.println(content);