import java.io.*;
import java.text.*;
import java.lang.String;
import java.util.*;
import java.lang.*;
import java.io.FileOutputStream;
import java.sql.*;
import oracle.sql.*;
import oracle.jdbc.driver.*;

public class zhu
{
public static void main(String[] args) throws Exception
{
String sql = "select id from table where rownum<=20";
String fields = "";
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection conn = DriverManager.getConnection("jdbc:oracle:oci:@连接名","user","pass");
Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stmt.executeQuery(sql);
while (rs.next())
{
fields = (rs.getString("id")!=null)? rs.getString("id") : "";
System.out.println(fields);
}
rs.close();
stmt.close();
conn.close();
}
}