[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);
}
}
}