userlist.java

J2EE独立开发制作

package bookstore;

import java.sql.*;
import java.util.*;

public class UserList
{
private static Map userMap;//用户ID和用户名的Map
//将用户数据缓存到Map中
public static void fillUser()
{
if (userMap == null)
{
userMap = new HashMap();
} 
else
{
userMap.clear();
}
Connection conn = null;
StringBuffer sBuf = new StringBuffer();
try
{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver" ); 
conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;databaseName=pubs", "sa", ""); 
PreparedStatement pStat = conn.prepareStatement("select pub_id,pub_name from publishers");
ResultSet rs = pStat.executeQuery();
while (rs.next())
{
userMap.put(rs.getString(1), rs.getString(2));
}
} 
catch (Exception ex)
{
ex.printStackTrace();
} finally
{
try
{
if (conn != null)
{
conn.close();
conn = null;
}
} catch (SQLException ex1)
{
ex1.printStackTrace();
}
}
}

//获取HTML下拉框的用户列表代码
public static String getUserListHTML()
{
StringBuffer sBuf = new StringBuffer();
Set set = userMap.keySet();
Iterator iter = set.iterator();
while (iter.hasNext())
{
Object item = (Object) iter.next();
sBuf.append("<option value=’" + item + "’>" +
userMap.get(item) + "</option>\n");
}
return sBuf.toString();
}
}