javaexceptionserializationeofexception

Java Mysterious EOF exception with readObject


The following code produces an EOFException. Why is that?

public static Info readInfoDataFromFile(Context context) {
    Info InfoData = null;
    FileInputStream fis = null;
    ObjectInputStream ois = null;
    Object object = null;

    if (context.getFileStreamPath("InfoFile.dat").exists()) {
        try {
            fis = context.openFileInput("InfoFile.dat");
            ois = new ObjectInputStream(fis);
            Object temp;
            try {
                // here it throws EOF exception in while loop 
                while ((temp = ois.readObject()) != null) {
                    object = temp;
                }
            } catch (NullPointerException npe) {
                npe.printStackTrace();
            } catch (EOFException eof) {
                eof.printStackTrace();
            } catch (FileNotFoundException fnfe) {
                fnfe.printStackTrace();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (ois != null) {
                    ois.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (fis != null) {
                    fis.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

StackTrace:

03-07 14:29:01.996: WARN/System.err(13984): java.io.EOFException
03-07 14:29:01.996: WARN/System.err(13984):     at java.io.DataInputStream.readByte(DataInputStream.java:131)
03-07 14:29:01.996: WARN/System.err(13984):     at java.io.ObjectInputStream.nextTC(ObjectInputStream.java:628)
03-07 14:29:01.996: WARN/System.err(13984):     at java.io.ObjectInputStream.readNonPrimitiveContent(ObjectInputStream.java:907)
03-07 14:29:01.996: WARN/System.err(13984):     at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2262)03-07 14:29:01.996: WARN/System.err(13984):     at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2217)
03-07 14:29:01.996: WARN/System.err(13984):     at 

Solution

  • Depends on how many objects your file contains. If it has only one object, you can deserialise in one step.

    try {
        Object temp = ois.readObject();
    }
    catch(Exception e) {
        //handle it
    }