select对应的action

package action;
import java.sql.*;
import com.opensymphony.xwork2.ActionSupport;
import com.sun.org.apache.bcel.internal.generic.RETURN;
import db.DBConn;
import POJO.Msg_stand;
import java.util.ArrayList;
import  java.util.Map;

public class select extends ActionSupport {

    private  int send_uid;//发件人
    private String subject;//主题
    private String create_time;//发件时间
    public String action;//操作类型


public int getSend_uid() {
  return send_uid;
}
public void setSend_uid(int send_uid) {
  this.send_uid = send_uid;
}

public String getSubject() {
  return subject;
}
public void setSubject(String subject) {
  this.subject = subject;
}

  public String getCreate_time() {
  return create_time;
}
public void setCreate_time(String create_time) {
  this.create_time = create_time;
}
    @Override
    public String execute()throws Exception{
    Connection conn=DBConn.createDBConn();
   if("del".equals(action)){
   String sql="delete from msg_stand where send_uid=?";
   PreparedStatement preSQLDel=conn.prepareStatement(sql);
   preSQLDel.setInt(1,send_uid);
   preSQLDel.executeUpdate();

        }

else{
  String sql="select subject,send_uid,create_time from msg_stand where send_uid=?";
  PreparedStatement preSQLSel=conn.prepareStatement(sql);
  Statement stmt=conn.createStatement();
  ResultSet rs=stmt.executeQuery(sql);
  preSQLSel.setInt(1, send_uid);
  //preSQLSel.executeQuery(sql);
ArrayList<Msg_stand> msg_standArrayList=new ArrayList<Msg_stand>();

while(rs.next()){
  Msg_stand msg_stand =new Msg_stand();
  msg_stand.setSend_uid(rs.getInt("send_uid"));
  msg_stand.setSubject(rs.getString("subject"));
  msg_stand.setCreate_time(rs.getString("create_time"));
  msg_standArrayList.add(msg_stand);
}
      
    }
     return SUCCESS;
}
}