java-第二个sql语句得到的resultset对象是空的怎么办

java数据库mysql计算机jsp

public ListgetAll1(String name) throws Exception {

Listresult = new ArrayList();

Connection con = DatabaseConnection.getConnection() ;

String na=null;

String sql1= "select * from guanzhu where guanzhu=?";

PreparedStatement ps1 = con.prepareStatement(sql1);

ps1.setString(1, name);

ResultSet rs1 = ps1.executeQuery();

while(rs1.next()){

连接con1 = DatabaseConnection.getConnection();

na=rs1.getString("beiguanzhu");

String sql = "select * from message whereauthor=? order bymodified desc"; PreparedStatement ps = con1.prepareStatement(sql);

ps.setString(1, na); ResultSet rs = ps.executeQuery();

while (rs.next()) {

消息 m = new Message();

m.setId(rs. getInt("id"));

m.setTitle(rs.getString("title"));

m.setContent(rs.getString("content"));

m.setModified(rs.getDate("modified"));

m.setAuthor(rs.getString("author"));

result.add(m) ;

System.out.println(rs.getString("author") "");

}

}

返回结果;
}