JDBC connect to oracle

Environment: myEclipse7.0+oracle10.2(client)

//必须加入classes12.jar 此文件在oracle client的jdbc/lib找.

package PackgeTest1;
import java.sql.*;
import javax.swing.JOptionPane;

public class ConnectOracle {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//jdbc:oracle:thin:@localhost:1521:SID"; 数据库的SID为oracle client中的SERVICE_NAME
String url="jdbc:oracle:thin:@ServerIP:1521:ORASVR";
String user="username";
String password="password";
Connection conn=null;
try{

Class.forName("oracle.jdbc.driver.OracleDriver");
conn=DriverManager.getConnection(url,user,password);
}catch(ClassNotFoundException e){
System.out.println("找不到驱动");
}catch(SQLException e){
System.out.println("数据库连接失败");
}
try{
System.out.println("123");
Statement stmt=conn.createStatement();
String queryAll="select * from Table";
ResultSet rs=stmt.executeQuery(queryAll);
while(rs.next()){
System.out.println(rs.getString("EMP_ID"));
JOptionPane.showMessageDialog(null,rs.getString("EMP_ID"));
}
}catch(SQLException e){
System.out.println("faile");

}
}

}

TNSNAMES.ora
ORASVR =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = Server IP Address)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ORASVR)
)
)