- Tha main purpose of the project:
- classes:
we want to develop an application to send the quireis of POSTGIS on a friendly GUI by using Java. Swing in Java is a Graphical User Interface (GUI) toolkit that includes the GUI components. Swing provides a rich set of widgets and packages to make sophisticated GUI components for Java applications. Swing is a part of Java Foundation Classes(JFC), which is an API for Java GUI programing that provide GUI. see more information about postGIS.
contains all the configuration requirements for our project to interact with the database.
/ //Creates a JFrame with the specified title and the specified GraphicsConfiguration of a screen.
JFrame frame = new JFrame("PostGIS QUERY ");
//A property list that contains default values for any keys not found in this property list
Properties props = new Properties();
// creat an object of ConnectDialog
ConnectDialog dialog = new ConnectDialog(frame, "Database Connectro", props);
dialog.setVisible(true);
//status – exit status.
if (dialog.iscancelled)
System.exit(0);
//// creat an object of Connector
Connector conn = new Connector(dialog.getPros(), new String(dialog.pass.getPassword()));
if (!conn.open())
System.exit(0);
// creat an object of PostgreSQLJDBC
PostgreSQLJDBC dpanal = new PostgreSQLJDBC(conn);
frame.setSize(800, 600);
//add
frame.add(dpanal);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);PostgreSQL is a powerful, open source SQL database with the object-relational structure and numerous robust features to ensure excellent performance and reliability.
public class Connector {
Connection conn;
Statement stat;
/*
*connect to postgresql
*/
//Try to make a database connection to the given URL. The driver should return "null" if it realizes it is the wrong
// kind of driver to connect to the given URL. This will be common, as when the JDBC driverManager is asked to connect to a given URL,
// it passes the URL to each loaded driver in turn.
static String url, database, username, password, hostname, port, driver;
public Connector(Properties pros, String pass) {
database = pros.getProperty("Database");
/*
* Find Users in PostgreSQL SELECT usename FROM pg_user;
*/
username = pros.getProperty("User_Name");
password = pass;
/*
* SELECT boot_val,reset_val FROM pg_settings WHERE name='listen_addresses';
*/
hostname = pros.getProperty("Host_Name");
/*
* SELECT * FROM pg_settings WHERE name = 'port';
*/
port = pros.getProperty("Port");
driver = "org.postgresql.Driver";
url = "jdbc:postgresql://" + hostname + ":" + port + "/" + database;
}
public boolean open() {
try {
Class.forName("org.postgresql.Driver");
conn = DriverManager.getConnection(url, username, password);
stat = conn.createStatement();
} catch (Exception e) {
System.out.println("The connection failed");
e.printStackTrace();
if (conn == null)
return false;
}
System.out.println("Connection successful");
return true;
}
public ResultSet excuteQury(String s) throws SQLException {
// TODO Auto-generated method stub
return stat.executeQuery(s);
}
public void executeUpdate(String s) throws SQLException {
stat.executeUpdate(s);
}
}boolean iscancelled = true;
// create labels for host,port, databasename,user name and password
JLabel lhost = new JLabel("Host Name");
JTextField host = new JTextField();
JLabel lport = new JLabel("Port");
JTextField port = new JTextField();
JLabel ldatabase = new JLabel("Database");
JTextField database = new JTextField();
JLabel lusr = new JLabel("User Name");
JTextField user = new JTextField();
JLabel lpass = new JLabel("User Name");
JPasswordField pass = new JPasswordField();
// add Buttons
JButton ok = new JButton("Ok");
JButton cancel = new JButton("cancel");
// Properties object
Properties props;
public ConnectDialog(JFrame owner, String title, Properties p) {
super(owner, title, true);
setSize(300, 200);
setLocation(250, 200);
props = new Properties(p);
ok.setPreferredSize(new Dimension(75, 25));
ok.addActionListener(this);
cancel.setPreferredSize(new Dimension(75, 25));
cancel.addActionListener(this);
JPanel cpanal = new JPanel();
JPanel cpanal2 = new JPanel();
// add grid
cpanal.setLayout(new GridLayout(5, 2));
cpanal.add(lhost);
cpanal.add(host);
cpanal.add(lport);
cpanal.add(port);
cpanal.add(ldatabase);
cpanal.add(database);
cpanal.add(lusr);
cpanal.add(user);
cpanal.add(lpass);
cpanal.add(pass);
// add to sacond panal
cpanal2.add(ok);
cpanal2.add(cancel);
add(cpanal, BorderLayout.NORTH);
add(cpanal2, BorderLayout.SOUTH);
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if (e.getSource() == ok)
iscancelled = false;
this.dispose();
}
public Properties getPros() {
props.setProperty("Database", database.getText());
props.setProperty("Host_Name", host.getText());
props.setProperty("Port", port.getText());
props.setProperty("User_Name", user.getText());
return props;
}
}¡– Download PostgreSQL JDBC driver. JDBC database URL for PostgreSQL The syntax of database URL for PostgreSQL looks like the following forms: jdbc:postgresql:database jdbc:postgresql://host/database jdbc:postgresql://host:port/database jdbc:postgresql://host:port/database?param1=value1¶m2=value2&…
j- Register JDBC driver for PostgreSQL Server and create connection
static JTextArea sql = new JTextArea();
JLabel promt = new JLabel("Type your PostgreSQL statement below:");
JButton exe = new JButton("Excute");
JButton reset = new JButton("Reset");
static JTable table = new JTable();
//an implementation of TableModel that uses a Vector of Vectors to store the cell value objects.
static DefaultTableModel model = (DefaultTableModel) table.getModel();
static Connector dc;
public PostgreSQLJDBC(Connector conn) {
add(promt);
dc = conn;
//JScrollPane manages a viewport, optional vertical and horizontal scroll bars, and optional row and column heading viewports.
JScrollPane spane = new JScrollPane(sql);
spane.setPreferredSize((new Dimension(750, 100)));
add(spane);
exe.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
excute();
}
});
reset.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
model.setColumnCount(0);
model.setRowCount(0);
}
});
add(exe);
add(reset);
// add(table);
JScrollPane rspan = new JScrollPane(table);
rspan.setPreferredSize((new Dimension(750, 100)));
add(rspan);
}
private static void excute() {
model.setColumnCount(0);
model.setRowCount(0);
String s = sql.getText();
try {
if (s.length() >= 6 && s.substring(0, 6).equalsIgnoreCase("SELECT")) {
ResultSet rs = dc.excuteQury(s);
ResultSetMetaData rsmd = rs.getMetaData();
for (int i = 1; i <= rsmd.getColumnCount(); i++) {
model.addColumn(rsmd.getColumnName(i));
}
while (rs.next()) {
String[] data = new String[rsmd.getColumnCount()];
for (int i = 1; i <= rsmd.getColumnCount(); i++) {
data[i - 1] = rs.getString(i);
}
model.addRow(data);
}
} else
dc.executeUpdate(s);
} catch (SQLException e) {
System.out.println("Error: " + e);
}
}
}when we run the program it shows the palce to enter the information to get the connection with data base:
after entring the requred information the new window will be opened as follow:
excute some quries:
CREATE DATABASE test;CREATE a table:
CREATE TABLE point
(
x float8,
y float8,
place varchar(100),
size float8,
update date,
startdate date,
enddate date,
title varchar(255),
url varchar(255),
the_geom geometry(POINT, 4326)
);- quiry on data:
Java GUI For PostGIS Query:
Implemented an application to send the quires of POSTGIS on a friendly GUI by using Java. Swing. defines how a client may access a database. It provides possibility for querying and updating data in a database on GUI. I am developing it to visualizing the routing algorithms (Shortest Path, Johnson’s Algorithm, A*, Dijkstra, Driving Distance and Traveling Salesperson Problem).