Error : org.postgresql.util.PSQLException: Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections in java

when i try to create some connection in java with JDCB Postgresql , i have some problem . I cant create connection succesfully .

here the code :

/*
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* and open the template in the editor.
*/

package Testapp;

/**
*
* @author penguintengil
*/
import java.sql.*;
import javax.swing.JOptionPane;
public class Login {
public Connection conn=null;
public final String driver=”org.postgresql.Driver”; //drivernya postgre
public final String user=”root”; //username
public final String pass=”root”; //password
public final String url=”jdbc:postgresql://localhost/test”; //url postgre

public void conn(){

try {
Class.forName(driver);
conn=DriverManager.getConnection(url,user,pass);
System.err.println(“Connection Success”);
} catch (Exception e) {
JOptionPane.showMessageDialog(null,”Connection Failed”);
System.err.println(“Error: “+e);
}

}
public static void main (String[]arg){
Login k = new Login();
k.conn();
}

Statement createStatement() {
throw new UnsupportedOperationException(“Not yet implemented”);
}
}

Compile > Run

if you got an error like

Error : org.postgresql.util.PSQLException: Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections

Lets try to fix this

check configuration in /var/lib/pgsql/data/pg_hba.conf

put some

# TYPE DATABASE USER ADDRESS METHOD

# “local” is for Unix domain socket connections only
local all all trust
# IPv4 local connections:
host all all 127.0.0.1/32 trust
# IPv6 local connections:
host all all ::1/128 trust
# Allow replication connections from localhost, by a user with the

local all all trust
host all all 127.0.0.1 255.255.255.255 trust
host all all ::1 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff trust

save

and then check  /var/lib/pgsql/data/postgresql.conf

change

listen_addresses=’*’

restart service

#service postgresql restart

Finally , running program .

and connection will be succesfull 🙂