아파치 더비를 이용한 오프라인 Ajax

public class Contact {
    
    private Integer id;
    private String firstName;
    private String lastName;
    private String email;
    
    public static List<Contact> getContacts(String clause){
        if (clause == null)
            clause = "";
        String sql = SELECT_SQL + clause;
        Connection conn = DbManager.getConnection();
        List<Contact> contacts = new ArrayList<Contact>();
        try {
            ResultSet cursor = conn.createStatement().executeQuery(sql);
            while (cursor.next()){
                Contact c = new Contact();
                c.setId(cursor.getInt(1));
                c.setFirstName(cursor.getString(2));
                c.setLastName(cursor.getString(3));
                c.setEmail(cursor.getString(4));
                contacts.add(c);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return contacts;
    }
    
    public static List<Contact> getAllContacts(){
        return Contact.getContacts(null);
    }
    
    public static Contact getContact(String clause){
        List<Contact> results = Contact.getContacts(clause);
        if (results == null || results.size() != 1){
            return null;
        }
        else return results.get(0);    
    }
    
    public void save(){
        if (id == null)
            insert();
        else
            update();
    }
    
    public void delete(){
        Connection conn = DbManager.getConnection();
        String sql = "delete from Contact where id=?";
        try{
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            ps.executeUpdate();
            System.out.println("Deleted contact id="+id);
        } catch (SQLException e){
            e.printStackTrace();
        }
    }
    
    private void insert() {
        Connection conn = DbManager.getConnection();
        try {
            PreparedStatement ps = conn.prepareStatement(INSERT_SQL, 
                    PreparedStatement.RETURN_GENERATED_KEYS);
            ps.setString(1, firstName);
            ps.setString(2, lastName);
            ps.setString(3, email);
            ps.executeUpdate();
            ResultSet autoRs = ps.getGeneratedKeys();
            if (autoRs.next()){
                id = autoRs.getInt(1);
            }
            System.out.println("Contact saved new id = " + id);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    private void update(){
        Connection conn = DbManager.getConnection();
        try{
            PreparedStatement ps = conn.prepareStatement(UPDATE_SQL);
            ps.setString(1, firstName);
            ps.setString(2, lastName);
            ps.setString(3, email);
            ps.setInt(4, id);
            ps.executeUpdate();
            System.out.println("Contact updated with id="+id);
        } catch (SQLException e){
            e.printStackTrace();
        }
    }
	

package org.developerworks.addressbook;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DbManager {
    static{
        try {
            Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } 
    }
    
    public static Connection getConnection(){
        try {
            Connection conn = DriverManager.getConnection("jdbc:derby:contacts;
create=true");
            return conn;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}

public class AddressBookApplet extends JApplet {
    private static final long serialVersionUID = 1L;    
    private static final String[] columns = { "First Name", "Last Name", "Email", "Id"};
    
    public AddressBookApplet() {
        this.setLayout(new GridLayout(1,0));
        JPanel panel = buildUi();
        this.add(panel);
    }

    public Contact addContact(String firstName, String lastName, String email) {
        Contact c = new Contact();
        c.setFirstName(firstName);
        c.setLastName(lastName);
        c.setEmail(email);
        c.save();
        return c;
    }
    
    public void deleteContact(Integer id){
        Contact c= new Contact();
        c.setId(id);
        c.delete();
    }

    public Object[][] loadContacts() {
        List<Contact> book = Contact.getAllContacts();
        Object[][] contacts = new Object[book.size()][4];
        int cnt = 0;
        for (Contact contact : book){
            contacts[cnt++] = contact.toArray();
        }
        return contacts;
    }

    private JPanel buildUi() {
        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        
        final DefaultTableModel dataModel = createDataModel();
        final JTable table = createTable(dataModel);
        
        //Lots of Swing/UI Code omitted for brevity    
      }
    
    private JTable createTable(final DefaultTableModel dataModel) {
        final JTable table = new JTable(dataModel);
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);
        return table;
    }

    private DefaultTableModel createDataModel() {
        Object[][] contacts = loadContacts();
        final DefaultTableModel dataModel = new DefaultTableModel(contacts, columns);
        return dataModel;
    }
}

$ keytool -genkey -alias sigs -keystore sigstore -keypass password -storepass password
What is your first and last name?
  [Unknown]:  Michael
What is the name of your organizational unit?
  [Unknown]:  developerWorks
What is the name of your organization?
  [Unknown]:  IBM
What is the name of your City or Locality?
  [Unknown]:  San Jose
What is the name of your State or Province?
  [Unknown]:  CA
What is the two-letter country code for this unit?
  [Unknown]:  US
Is CN=Michael, OU=developerWorks, O=IBM, L=San Jose, ST=CA, C=US correct?
  [no]:  yes

$ jarsigner -keystore sigstore -storepass password -keypass password -signedjar 
addrbook.jar derby.jar sigs

Warning: The signer certificate will expire within six months.

<applet alt="Address Book Applet" name="addrBookApplet" 
    code="org.developerworks.addressbook.AddressBookApplet"
    width="400" height="200" archive="addrbook.jar, derby.jar">
</applet>

function saveContact(firstName, lastName, email){
    var applet = document.addrBookApplet;
    var newContact = applet.addContact(firstName, lastName, email);
    addContactToUi(newContact);
}

<applet alt="Headless Applet" name="headlessApplet"
    code="org.developerworks.addressbook.HeadlesApplet"
    width="1" height="1" archive="addrbook.jar, derby.jar">
</applet>

function init(){
    var book = document.headlessApplet.loadContacts();
    var i = 0;
    var contact = {};
    for (i=0;i<book.length;i++){
        contact = {firstName:book[i][0], lastName:book[i][1], 
                    email:book[i][2], id:book[i][3]};
        addContactToUi(contact);
    }
}

function addContact(){
    var contact = {};
    var firstName = document.getElementById("firstName").value;
    var lastName = document.getElementById("lastName").value;
    var email = document.getElementById("email").value;
    var req = getXhr(); // get the browser specific XMLHttpRequest object
    var params = "firstName="+username + ",lastName="+lastName+",email="+email;
    req.open("POST", "/contact/create", true);
    req.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    req.setRequestHeader("Content-length", params.length);
    req.setRequestHeader("Connection", "close");
    req.onreadystatechange = handleResponse;    
    req.send(params);    
    // update cache
    saveContact(firstName, lastName, email);
}