建立一个 Derby 日历,第 2 部分: 嵌入选项(下)
2010-04-19 00:00:00 来源:WEB开发网对于 EventClass 类,只需要接收用户名和口令并保存到属性中。连接到数据库时,检索并使用该信息。
因为静态使用 Calendar 类,情况略有不同,如 清单 15 所示。
清单 15. Calendar 和用户信息
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
public class Calendar {
public static String driver =
"org.apache.derby.jdbc.ClientDriver";
private static Connection getConnection(String username,
String password) throws Exception {
Class.forName(driver).newInstance();
Connection conn = null;
conn = DriverManager.getConnection(
"jdbc:derby://localhost:1527/calendar;user="
+username+";password="+password);
return conn;
}
public static EventClass[] getEvents(int eventMonth,
int eventDay, int eventYear,
String username, String password) {
try {
Connection conn = getConnection(username, password);
Statement s = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
ResultSet rs = s.executeQuery("SELECT * FROM Event "+
"where eventMonth="+eventMonth+
" and eventDay="+eventDay+" and "+
"eventYear="+eventYear);
EventClass[] events = null;
if (!rs.next()){
return null;
} else {
rs.last();
int numberOfEvents = rs.getRow();
rs.beforeFirst();
events = new EventClass[numberOfEvents];
int thisEventIndex = 0;
EventClass thisEvent = null;
while (rs.next()) {
thisEvent = new EventClass(rs.getInt(1), username, password);
thisEvent.setTitle(rs.getString(2));
thisEvent.setDescription(rs.getString(3));
thisEvent.setRemindersTo(rs.getString(4));
thisEvent.setEventMonth(rs.getInt(5));
thisEvent.setEventDay(rs.getInt(6));
thisEvent.setEventYear(rs.getInt(7));
events[thisEventIndex] = thisEvent;
thisEventIndex = thisEventIndex + 1;
}
}
rs.close();
s.close();
conn.close();
try {
DriverManager.getConnection(
"jdbc:derby:;shutdown=true");
} catch (SQLException se) { }
return events;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static void main (String args[]){
int month = Integer.parseInt(args[0]);
int day = Integer.parseInt(args[1]);
int year = Integer.parseInt(args[2]);
getEvents(month, day, year, args[3], args[4]);
}
}
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