BinaryTree saved/loaded from Text File

Leaf

package binaryTree;

import java.io.Serializable;

public class Leaf implements Visualizable, Serializable {
    private int value;
    
    public Leaf(int value) {
        this.value = value;
    }

    @Override
    public void show() {
        System.out.println("<Leaf>");
        System.out.println("<Value>" + value + "</Value>");
        System.out.println("</Leaf>");
    }
}

Node

package binaryTree;

import java.io.Serializable;

public class Node implements Visualizable, Serializable {
    
    private Leaf value;
    private Visualizable leftSide;
    private Visualizable rightSide;

    public Node(int value, Visualizable leftSide, Visualizable rightSide) {
        this.value = new Leaf(value);
        this.leftSide = leftSide;
        this.rightSide = rightSide;
    }
    
    @Override
    public void show() {
        System.out.println("<Node>");
        value.show();
        leftSide.show();
        System.out.println("</LeftSide>");
        System.out.println("<RightSide>");
        rightSide.show();
        System.out.println("</RightSide>");
        System.out.println("</Node>");
    }
}

Reader

package marshalling;

import binaryTree.Visualizable;
import org.jboss.marshalling.*;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

// Stuff mostly taken from an example of the JBoss API
public class Reader {
    public Reader() {
    }

    public Visualizable readFrom(String fileName) {
        Object sourceObject = null;
        
        MarshallerFactory marshallerFactory = Marshalling.getProvidedMarshallerFactory("river");
        MarshallingConfiguration configuration = new MarshallingConfiguration();

        try {
            FileInputStream input = new FileInputStream(fileName);
            try {
                Unmarshaller unmarshaller = marshallerFactory.createUnmarshaller(configuration);
                ByteInput byteInput = Marshalling.createByteInput(input);

                unmarshaller.start(byteInput);
                sourceObject = unmarshaller.readObject();
                unmarshaller.finish();
                byteInput.close();
            } catch (IOException e) {
                System.out.print(" ERROR: Could not load from file");
            } catch (ClassNotFoundException exception) {
                System.out.print(" ERROR: Could not load from file");
            } finally {
                try {
                    input.close();
                } catch (IOException e) {
                }
            }
        } catch (FileNotFoundException exception) {
            System.out.print(" ERROR: Could not load from file");
        }
        
        return (Visualizable) sourceObject;
    }
}

TreeCreator

import binaryTree.Leaf;
import binaryTree.Node;
import binaryTree.Visualizable;
import marshalling.Reader;
import marshalling.Writer;

public class TreeCreator {
    
    public static void main(String[] arguments) {
        Visualizable binaryTree = new Node(3, new Node(4, new Leaf(6), new Leaf(5)), new Node(7, new Node(8, new Leaf(9), new Leaf(10)), new Leaf(11)));
        binaryTree.show();

        // using jboss-marshalling 1.3.0 and JBoss Marshalling Serial Protocol 1.3.0 from http://www.jboss.org/jbossmarshalling/downloads
        new Writer(binaryTree).putInto("BinaryTreeMarshaled.txt");

        Visualizable unmarshalledBinaryTree = new Reader().readFrom("BinaryTreeMarshaled.txt");
        unmarshalledBinaryTree.show();
    }
}

Visualizable

package binaryTree;

public interface Visualizable {
    
    void show();
}

Writer

package marshalling;

import binaryTree.Visualizable;
import org.jboss.marshalling.*;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

// Stuff mostly taken from an example of the JBoss API
public class Writer {
    private Visualizable binaryTree;
    
    public Writer(Visualizable binaryTree) {
        this.binaryTree = binaryTree;
    }
    
    public void putInto(String fileName) {
        MarshallerFactory marshallerFactory = Marshalling.getProvidedMarshallerFactory("river");
        MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(3);

        try {
            FileOutputStream output = new FileOutputStream(fileName);
            try {
                Marshaller marshaller = marshallerFactory.createMarshaller(configuration);
                ByteOutput byteOutput = Marshalling.createByteOutput(output);

                marshaller.start(byteOutput);
                marshaller.writeObject(binaryTree);
                marshaller.finish();
                output.close();
            } catch (IOException exception)  {
                System.out.print(" ERROR: Could not put into file");
            } finally {
                try {
                    output.close();
                } catch (IOException exception) {
                }
            }
        } catch (FileNotFoundException exception) {
            System.out.print(" ERROR: Could not put into file");
        }
    }
}