Storing object in database in Java

Question

I am trying to store my object in MySQL database using java language. I am trying to convert object into byte so I can store it into LONGBLOB. But I am facing error i.e "NotSerializable Exception".

My Class whose object I want to sore:

public class Books implements Serializable {

private int isbn;
private String bookName;
private String author;
private String edition;
private int rowNo;
private int colNo;
private String shelfNo;
private String img;
private InputStream imag;
validation v = new Validation();
Database database;

public Books() { database = new Database(); }
.
.
setters & getters...

Method to call database method to insert object in database:

String className = this.getClass().getName();
database.insertBookRecord(this.getIsbn(), this, className);

this is the object of current class which I want to store.

following is the insertBookRecord method.

    public void insertBookRecord(int isbn, Books book, String name) {
    String query = "INSERT INTO Test VALUES (?, ?, ?)";
    byte[] data = null;
    //book = new Books();
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(baos);
        oos.writeObject(book);
        oos.flush();
        oos.close();
        baos.close();
        data = baos.toByteArray();
    }
    catch(IOException ex) {
        JOptionPane.showMessageDialog(null, ex.getMessage());
    }

    try {

        //conn.setAutoCommit(false);
        state = conn.prepareStatement(query);
        state.setInt(1, isbn);
        state.setString(2, name);
        state.setObject(3, data);
        state.executeUpdate();
        //conn.commit();
    }
    catch(SQLException ex) {
        JOptionPane.showMessageDialog(null, ex.getMessage());
    }
    finally {
        close(3);
    }
}

When I reach at statement oos.writeObject(book); Its stops with exception and displays the the package & Classname in the JOptionPane.

My book object has all the data fields I entered in the text fields. But I am unable to write it./convert it into Serializable format.

Any suggestions please?

Stack Trace:

java.io.NotSerializableException: com.my.classes.Database
at java.io.ObjectOutputStream.writeObject0(Unknown Source)
at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source)
at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
at java.io.ObjectOutputStream.writeObject0(Unknown Source)
at java.io.ObjectOutputStream.writeObject(Unknown Source)
at com.my.classes.Database.insertBookRecord(Database.java:123)
at com.my.classes.Books.insertBookRecord(Books.java:107)
at com.my.jlms.ManageBooks$2.actionPerformed(ManageBooks.java:308)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

We would need to see the fields in your Books class. Or better yet something in there is not Serializable — 3kings
– 3kings, Commented Mar 30, 2016 at 13:53
Probably one or more of the fields inside your Book class is not serializable. Where's your stacktrace? — f1sh
– f1sh, Commented Mar 30, 2016 at 13:54
@nix Well there you see it... InputStream does not implement Serializable — 3kings
– 3kings, Commented Mar 30, 2016 at 13:57

Diyarbakir · Accepted Answer · 2016-03-30 13:59:48Z

1

You get the exception because you are trying to serialize an InputStream

private InputStream imag;

InputStream is not Serializable

You could omit this field when serializing by declaring it transient:

private transient InputStream imag;

answered Mar 30, 2016 at 13:59

Diyarbakir

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Comments

An Do · Accepted Answer · 2016-03-30 14:25:04Z

0

Your imag is InputStream which is not implement Serializable. It should be a byte[] or String link to your imag location.

Edited: You should separate business from model object. Move insertBook method and database object from Book class to another class.

edited Mar 30, 2016 at 14:25

answered Mar 30, 2016 at 14:03

An Do

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3 Comments

nix Over a year ago

I tried it, even removed InputStream, but still the same error. you ca view the stacktrace error pastebin.com/YwQf0izy

An Do Over a year ago

I see the problem. I don't know why you need database object in your book but please move your logic to another class String className = this.getClass().getName(); database.insertBookRecord(this.getIsbn(), this, className);

nix Over a year ago

I figured out the problem, its not serializing an object inside the other object. I mean if you see the code, I have declared constructor so its not serializing the database object, similarly its not serializing the validation object. If I remove them and put inside method, it works fine i.e serialization done. But I do want them in the field and constructor so I don't have declare them again and again. Is it possible to not let that serialize?

nix · Accepted Answer · 2016-03-30 21:46:05Z

0

So the problem was InputStream as well as i was trying to Seralize the objects i.e V & database. I just added transient e.g private transient Database database; and then declared database = new Database(); in the constructor. hence I was able to serialize it.

Thank you @Ralf, @Joseph, @Diyarbakir and @3kings for helping me out.

answered Mar 30, 2016 at 21:46

nix

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