NoSQL Tutorial
This tutorial aims to create a java
based user management application using MongoDB, a cross-platform, document oriented
database that provides high performance, high availability and easy
scalability. MongoDB works on concept of collection and document.
Prerequisites
1. MongoDB
2. MongoVUE
3. Eclipse with WindowBuilder
Task 1 – Run MongoDB server
1. Extract MongoDB zip file and move its
contents to a location of your choice (eg: c:\mongodb).
2. MongoDB requires a data folder to
store its files. You may create this directory in a location of your choice.
The default location for the MongoDB data directory is c:\data\db.
3. Open up a command prompt and navigate
to the bin directory in the mongodb installation folder.
4. Run mongod.exe by using the following
command:
|
mongod.exe --dbpath "C:\mondogb\data"
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This will
show waiting for connections message on the console output which indicates that
the mongod.exe process is running successfully.
Task 2 – Create new database and
collection for storing user data
1. Connect to
MongoDB server using MongoVUE.
2. Create new
database by right clicking on the server node and selecting “Add Database”.
Name the new database as “usermanager”.
3. Add new
collection to usermanager database by right clicking on the database node and
selecting “Add Collection”. Name the new collection as “user”.
Task 3 – Create client application
1. Open
Eclipse and create a new java project.
a. Select File
> New > Project.
b. Expand
‘Java’ node and select ‘Java Project’. Click ‘Next’.
c. Name the
project as ‘UserManager’ and click ‘Finish’.
2. Add MongoDB
Java driver to the classpath.
a. Right click
project node and select ‘Properties’.
b. Select
‘Java Build Path’ and go to ‘Libraries’ tab.
c. Click on
‘Add Externam JARs’ button and browse for the jar file.
d. Click ‘OK’
to close the window.
3. Add
‘DBManager’ singleton class for managing database connections
a. Right click
src node > New > Class.
b. Name the
new class as DBManager.
c. Click
‘Finish’.
d. Add the
following code to the new class:
|
import
java.net.UnknownHostException;
import com.mongodb.DB;
import
com.mongodb.MongoClient;
public class DBManager {
private static DB database;
public static DB getDatabase() {
if(database == null) {
MongoClient
mongo;
try {
mongo = new MongoClient("localhost", 27017);
database = mongo.getDB("usermanager");
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return database;
}
}
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4. Create User
entity class.
a. Add a new
class and name it as ‘User’.
b. Add the
following code to the User class:
|
package
lk.sliit.usermanager.model;
public class User {
private int id;
private String firstName;
private String lastName;
private String email;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirstName()
{
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
|
|
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
|
5. Add a new
jFrame to the project and name it as ‘Main’
a. Right click
on src node and select New > Other.
b. Search for
‘jFrame’ and click ‘Next’.
c. Name the
new jFrame as ‘Main’ and click ‘Finish’.
6. Design the
following user interface using the design tool
7. Code for
the ‘Add User’ button is given below:
|
btnAddUser.addActionListener(new ActionListener() {
public void
actionPerformed(ActionEvent arg0) {
User
newUser = new User();
newUser.setId(Integer.parseInt(txtId.getText()));
newUser.setFirstName(txtFirstName.getText());
newUser.setLastName(txtLastName.getText());
newUser.setEmail(txtEmail.getText());
DBObject
doc = createDBObject(newUser);
DB
userDB =
DBManager.getDatabase();
DBCollection
col = userDB.getCollection("user");
WriteResult
result = col.insert(doc);
}
});
|
|
private static DBObject createDBObject(User user) {
BasicDBObjectBuilder docBuilder =
BasicDBObjectBuilder.start();
docBuilder.append("_id", user.getId());
docBuilder.append("firstName", user.getFirstName());
docBuilder.append("lastName", user.getLastName());
docBuilder.append("email", user.getEmail());
return docBuilder.get();
}
|
MYAPP
viewUser
add
table and type code
//
public ViewUser() {
// initComponents();
viewUserData();
//}
public void viewUserData() {
DefaultTableModel model = new DefaultTableModel();
model.addColumn("ID");
model.addColumn("First Name");
model.addColumn("Last Name");
model.addColumn("Email");
DB userDB = DBManager.getDatabase();
DBCollection col = userDB.getCollection("user");
DBCursor cursor = col.find();
while (cursor.hasNext()) {
DBObject user = (DBObject)
cursor.next();
model.addRow(new
Object[]{user.get("_id"), user.get("firstName"),
user.get("lastName"), user.get("email")});
}
jTable1.setModel(model);
}
manageUser
fill combobox
//public manageUser() {
//
initComponents();
fillID();
//
}
public void fillID() {
DB userDB = DBManager.getDatabase();
DBCollection col = userDB.getCollection("user");
DBCursor cursor = col.find();
while (cursor.hasNext()) {
DBObject user = (DBObject)
cursor.next();
jComboBox1.addItem(user.get("_id"));
}
}
Combobox change event should select
private void
jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {
// TODO add your handling code here:
DB userDB = DBManager.getDatabase();
DBCollection col = userDB.getCollection("user");
DBCursor cursor = col.find();
while (cursor.hasNext()) {
DBObject user = (DBObject)
cursor.next();
int seletedID =
Integer.parseInt(jComboBox1.getSelectedItem().toString());
if (Integer.parseInt(user.get("_id").toString())
== seletedID) {
jTextField1.setText(user.get("_id").toString());
jTextField2.setText(user.get("firstName").toString());
jTextField3.setText(user.get("lastName").toString());
jTextField4.setText(user.get("email").toString());
}
}
}
Update user
try {
DB userDB =
DBManager.getDatabase();
DBCollection col =
userDB.getCollection("user");
BasicDBObject query = new
BasicDBObject("_id", new BasicDBObject("$eq",
Integer.parseInt(jTextField1.getText())));
BasicDBObject newDocument = new
BasicDBObject();
newDocument.put("firstName", jTextField2.getText());
newDocument.put("lastName",
jTextField3.getText());
newDocument.put("email",
jTextField4.getText());
BasicDBObject updateObj = new
BasicDBObject();
updateObj.put("$set",
newDocument);
col.update(query, updateObj, false,
true);
JOptionPane.showMessageDialog(rootPane, "User Update
SucessFully...!");
jTextField1.setText("");
jTextField2.setText("");
jTextField3.setText("");
jTextField4.setText("");
} catch (Exception e) {
JOptionPane.showMessageDialog(rootPane, "Please Select User");
}
Delete user
try {
DB userDB =
DBManager.getDatabase();
DBCollection col =
userDB.getCollection("user");
BasicDBObject query = new
BasicDBObject("_id", new BasicDBObject("$eq",
Integer.parseInt(jTextField1.getText())));
col.remove(query);
JOptionPane.showMessageDialog(rootPane, "User Delete
SucessFully...!");
this.setVisible(false);
this.dispose();
manageUser mange = new
manageUser();
mange.setVisible(true);
} catch (Exception e) {
JOptionPane.showMessageDialog(rootPane, "Please Select User");
}
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