Writing Objects to file using Externalizable

Question

Hi,
I'm trying to write an object to file. My sample code is:
public class Junk implements Externalizable{
private static java.util.Random generator = new java.util.Random();
private int answer;
private double[] numbers;
private String thought;
public Junk(String thought) {
this.thought = thought;
answer = 42;
numbers = new double[3+ generator.nextInt(4)];
for (int i=0; i<numbers.length; i++) {
numbers[i] = generator.nextDouble();
public void writeExternal(ObjectOutput stream) throws java.io.IOException {
stream.writeInt(answer);
stream.writeBytes(thought);
for(int i=0; i< numbers.length; i++) {
stream.writeDouble(numbers);
public void readExternal(ObjectInput stream) throws java.io.IOException {
answer = stream.readInt();
String thought = stream.readUTF();
and the class with main() is:
package MyTest;
import java.io.*;
public class SerializeObjects {
public SerializeObjects() {
public static void main(String args[]) {
Junk obj1 = new Junk("A green twig is easily bent.");
Junk obj2 = new Junk("A little knowledge is a dangerous thing.");
Junk obj3 = new Junk("Flies light on lean horses.");
ObjectOutputStream oOut = null;
FileOutputStream fOut = null;
try {
fOut = new FileOutputStream("E:\\FileTest\\test.bin");
oOut = new ObjectOutputStream(fOut);
obj1.writeExternal(oOut);
//obj2.writeExternal(oOut);
} catch (IOException e) {
e.printStackTrace(System.err);
System.exit(1);
try {
oOut.flush();
oOut.close();
fOut.close();
} catch(IOException e) {
e.printStackTrace(System.err);
System.exit(1);
The output I get in test.bin contains some junk ascii codes. The only item that is written correctly in the file is the string.
Is there anyway I can write correct data into a file?
My output needs to be a readable text format file.
Can anyone help please?

Answer 1

obj1.writeExternal(oOut);This should be
oOut.writeObject(obj1);However,
The output I get in test.bin contains some junk ascii
codes. The only item that is written correctly in the
file is the string.If you don't want 'junk' don't use Externalizable and ObjectOutputStream at all, just use PrintStream/PrintWriter.println().