Looping through a ObjectInputStream in one method and print entire file in the main method, but havi-CodePudding

So I have a working ObjectOutputStream in a method that I start by calling the method in main. I need to then read the file it created and print out all 5 objects in it. Right now I'm only printing out the first object.

public static AccountSerializable serializReadObject() throws ClassNotFoundException, IOException {
        AccountSerializable read = null;
        try { // Create an input stream for file accounts.ser
            ObjectInputStream input = new ObjectInputStream(new FileInputStream("accounts.ser"));
            read = (AccountSerializable) input.readObject();
            input.close();
        } catch (IOException i) {
            throw i;
        }catch(ClassNotFoundException c){
            throw c;
            
        }
        return read;

    }

    public static void main(String[] args) {

        try {
            System.out.println(serializReadObject());
        } catch (ClassNotFoundException | IOException e) {
            System.out.println("Class not found");
            e.printStackTrace();
        }
    }

I've tried to throw

boolean eof = false;
while(!eof){
try{
//read data
}catch(EOFException e){
eof = true;
}
}

in serializReadObject To loop it and I've also tried to instead catch it in main but I keep getting an error stating "Unreachable catch block for EOFException it is already handled by the catch block" I then tried to take away the IOException and just put EOFEception but alas it keeps forcing me to surround my read with IOException. Is there another way to loop this with EOF?

CodePudding user response：

You're only getting the first object because your opening and closing the stream on each call. There are many ways to achieve what you want. One way is to use a List<AccountSerializable>:

public static List<AccountSerializable> serializeReadObjects() throws IOException, ClassNotFoundException {
    // create an input stream for file accounts.ser
    // this line will throw an IOException if something goes wrong 
    // we don't need to catch it in this method though
    ObjectInputStream input = new ObjectInputStream(new FileInputStream("accounts.ser"));
    
    // create list to hold read in accounts
    List<AccountSerializable> accounts = new ArrayList<>();

    // keep reading until EOFException is thrown
    boolean keepReading = true;
    while(keepReading) {
        
        try {
            // read in serialized account
            AccountSerializable read = (AccountSerializable) input.readObject();
            // add read in serialized account to the list
            accounts.add(read);

        } catch(EOFException eofe) {
            // we are at the end of file, so stop reading
            keepReading = false;
            input.close();

        } catch(IOException ioe) {
            // input stream error other than EOF, not sure what to do
            input.close();
            throw ioe;
        } catch(ClassNotFoundException cnfe) {
            // not sure what to do in this case, so close input
            input.close();
            throw cnfe;
        }

    }
    
    return accounts;
}

public static void main(String[] args) {
    List<AccountSerializable> accounts = null;
    
    try {
        // get list of read in accounts
        accounts = serializeReadObjects();
    } catch (ClassNotFoundException | IOException e) {
        e.printStackTrace();
    }
    
    // iterate over list of read in accounts and output them to stdout
    for(AccountSerializable account : accounts) {
        System.out.println(account);
    }
}