CODEWITHSUNDEEP
java
Joseph Michael
Joseph Michael

Reputation: 77

Update Serialized Object in Java

Is there a way to read a serialized object from a .ser file and update or delete one of the objects that have been serialized?

The following is my code which read's in objects of type 'Driver':

public boolean checkPassword(String userName, String password, String depot) throws IOException {       
    FileInputStream fileIn = new FileInputStream("Drivers.ser");
    ObjectInputStream in = new ObjectInputStream(fileIn);
               
    try
    {           
        while (true) {              
            Driver d = (Driver) in.readObject();
            
            if (d.userName.equals(userName) && d.password.equals(password) && d.depot.equals(depot)) 
            {
                this.isManager = d.isManager;
                validAccount = true;
            }
        }
    }
    catch (Exception e) {}  
    
    return validAccount;
}

Upvotes: 0

Views: 683

Answers (1)

Stephen C
Stephen C

Reputation: 719346

You will need to read all objects from the original file and then write a new file containing only the objects you want to retain or update.

The Java serialized object stream format is not an archive file format like ZIP, JAR, TAR and so on. It is just a sequence of serialized objects. There is no "index" that would facilitate updating or deleting objects.

This is one reason why serialized objects are not a good way to implement data persistence. This is what databases are designed for.

Upvotes: 1

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