Question

I am saving out and loading mixed data types. I either have the saving part wrong or the loading part wrong. I am using buffered serial save and load method.
Variable lastFetchDate is defined as a string and initialized as “00/00/00”.
It throws an error when reloading the data after it has been saved. What is wrong? I would have thought the opposite to writeBytes would be readBytes for a string.

Saving is as follows:

  FileOutputStream fos = new FileOutputStream("userPrefs.dat"); 
  BufferedOutputStream bos = new BufferedOutputStream(fos);   
  ObjectOutputStream oos = new ObjectOutputStream(bos);
  oos.writeBytes(lastFetchDate);
  // I close all streams

Loading is as follows:

  FileInputStream fis = new FileInputStream("userPrefs.dat"); 
  BufferedInputStream bis = new BufferedInputStream(fis);   
  ObjectInputStream ois = new ObjectInputStream(bis);
  lastFetchDate=(String)ois.readObject();  //<<<<< Error thrown here
  // I close all streams

Answer 1

You have written string as byte[] so need to read as byte[]

    byte [] bString = new byte[lastFetchDate.length()*2];
    ois.readFully(bString, 0, bString.length);

Or if you write as Object using writeObject method then you can read as object,

oos.writeObject(lastFetchDate);