Java Reference
In-Depth Information
import java.io.Serializable;
public class Junk implements Serializable {
private static java.util.Random generator = new java.util.Random();
private int answer; // The answer
private double[] numbers; // Valuable data
private String thought; // A unique thought
private static final long serialVersionUID = 9001L;
public Junk(String thought) {
this.thought = thought;
answer = 42;
// Answer always 42
numbers = new double[3+generator.nextInt(4)]; // Array size 3 to
6
for(int i = 0 ; i<numbers.length ; ++i) {
// Populate with
numbers[i] = generator.nextDouble();
// random values
}
}
@Override
public String toString() {
StringBuffer strBuf = new StringBuffer(thought);
strBuf.append('\n').append(String.valueOf(answer));
for(int i = 0 ; i<numbers.length ; ++i) {
strBuf.append("\nnumbers[")
.append(String.valueOf(i))
.append("] = ")
.append(numbers[i]);
}
return strBuf.toString();
}
}
Directory "SerializeObjects"
An object of type
Junk
has three instance fields: A simple integer that is always 42, a
String
object, and
an array of
double
values. The
toString()
method provides a
String
representation of a
Junk
object
that you can output to the command line. The static field
generator
is not written to the stream when an
object of type
Junk
is serialized. The only provision you have made for serializing objects of type
Junk
is to declare that the class implements the
Serializable
interface.
You can write objects of this class type to a file with the following program:
