[root@localhost ~]# ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:17:31:5C:E5:52  
          inet addr:192.168.1.90  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::217:31ff:fe5c:e552/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:111937 errors:0 dropped:0 overruns:0 frame:0
          TX packets:51525 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:31314300 (29.8 MiB)  TX bytes:6420495 (6.1 MiB)
          Interrupt:17 Base address:0x2000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:10738 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10738 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:79110566 (75.4 MiB)  TX bytes:79110566 (75.4 MiB)

sit0      Link encap:IPv6-in-IPv4  
          NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)
[root@localhost ~]# cat /etc/resolv.conf
; generated by /sbin/dhclient-script
nameserver 192.168.1.1
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
# Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller
DEVICE=eth0
BOOTPROTO=none
HWADDR=00:17:31:5C:E5:52
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes
NETMASK=255.255.255.0
IPADDR=192.168.1.90
GATEWAY=192.168.1.1
[root@localhost ~]# ping -c 10 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=254 time=0.958 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=254 time=0.846 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=254 time=1.01 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=254 time=0.899 ms
pi64 bytes from 192.168.1.1: icmp_seq=5 ttl=254 time=1.01 ms
n64 bytes from 192.168.1.1: icmp_seq=6 ttl=254 time=0.833 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=254 time=1.31 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=254 time=0.880 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=254 time=1.10 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=254 time=0.871 ms
[root@localhost ~]# ping google.com.vn
PING google.com.vn (72.14.207.104) 56(84) bytes of data.
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=1 ttl=238 time=290 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=2 ttl=238 time=292 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=3 ttl=238 time=295 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=4 ttl=238 time=295 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=5 ttl=238 time=290 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=6 ttl=238 time=294 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=7 ttl=238 time=295 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=8 ttl=238 time=293 ms
64 bytes from eh-in-f104.google.com (72.14.207.104): icmp_seq=9 ttl=238 time=300 ms

import java.sql.*;
public class DB {
	private String driver = "com.mysql.jdbc.Driver";
	private String host = "jdbc:mysql://localhost";
	private String dbName = "test";
	private int port = 3306;
	private String userDB = "root";
	private String passDB = "macarong";
	private Statement sta;
	
	public DB() {
		super();
	}
	
	public void connect() throws Exception {
		Class.forName(driver);
		String url = host + ":" + port + "/" + dbName;
		Connection con = DriverManager.getConnection(url,userDB,passDB);
		sta = con.createStatement();
	}
	
	public ResultSet execSQL(String query) throws Exception {
		ResultSet res = sta.executeQuery(query);
		return res != null ? res : null;
	}
	
	public int updateSQL(String sql) throws Exception {
		int i = sta.executeUpdate(sql);
		return i > 0 ? i : 0;
	}
}

import java.sql.*;
public class mystack {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		DB db = new DB();
		try {
			db.connect();
			ResultSet rs = db.execSQL("select * from User");
			while(rs.next()) {
				System.out.print(rs.getString("Username") + "\t" + rs.getString("Email"));
			}
		} catch (Exception e) {
			System.out.print("Loi he thong:" + e);
		}
	}

}