I was looking to work with serialization in java files and read this tutorial on how to write the object in the file and this one on the how to read the file object
Then I created the following class that saves the Adreess object in the file "file.ser":
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import wl.revisao.write.Address;
public class WriteObject {
public void serializeAddressJDK7(Address address) {
try (ObjectOutputStream oos
= new ObjectOutputStream(new FileOutputStream("arquivo.ser",true))) {
oos.writeObject(address);
System.out.println("Done");
} catch (Exception ex) {
ex.printStackTrace();
}
}
public Address deserialzeAddressJDK7(String filename) {
Address address = null;
try (ObjectInputStream ois
= new ObjectInputStream(new FileInputStream(filename))) {
address = (Address) ois.readObject();
} catch (Exception ex) {
ex.printStackTrace();
}
return address;
}
// Friend Isac's method with the answer below
public List<Address> recuperarTodos() {
List<Address> addresses = new ArrayList<Address>(); //lista de Address
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("arquivo.res"))) {
while (true) {
Address address = new Address();
address = (Address) ois.readObject(); //le outro objeto e adicionar à lista
addresses.add(address); //le outro objeto e adicionar à lista
}
} catch (EOFException ex) {
} catch (Exception ex) {
ex.printStackTrace();
}
return addresses;
}
}
Here is my main class:
public class Main {
public static void main(String args[]) {
WriteObject obj = new WriteObject();
Address address = new Address();
address.setStreet("Wall street");
address.setCountry("United States Of America");
Address address2 = new Address();
address2.setStreet("Avenida Brasil");
address2.setCountry("Brasil");
obj.serializeAddressJDK7(address);
obj.serializeAddressJDK7(address2);
// obj.deserialzeAddressJDK7("arquivo.ser");
System.out.println(obj.recuperarTodos());
}
}
The other method deserialzeAddressJDK7 returns an Address object read from the file.
Ok everything is perfect !! The problem is when I save more than one object in the file "file.ser" because the method was built to read only one object saved in the file;
How do I return a list of objects saved in such a file?
Finally the infamous class Address:
public class Address implements Serializable {
private static final long serialVersionUID = 1L;
String street;
String country;
public Address() {
}
public void setStreet(String street) {
this.street = street;
}
public void setCountry(String country) {
this.country = country;
}
public String getStreet() {
return this.street;
}
public String getCountry() {
return this.country;
}
@Override
public String toString() {
return new StringBuffer(" Street : ")
.append(this.street).append(" Country : ")
.append(this.country).toString();
}
}
ps: I'm using append as true, because as we know I want to accumulate the objects in the .ser file, and if I omitted it, that would not be possible! If there is another way to save the objects to the files without using append, and you can list those files, I'd be happy to see them. I used Boolean append commo true, because it was the only alternative I had ... I did not know how to rewrite in the file without deleting previously existing objects!
