JSP bss验证一个方法时，程序出错。

Question

package net.zhaodong.msg.dao.mysql.impl;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import net.zhaodong.msg.dao.IMsgDAO;
import net.zhaodong.msg.db.DBConnection;
import net.zhaodong.msg.entity.Msgentity;

public class MsgDaoMysqlImpl implements IMsgDAO {

public int insertOnmsg(Msgentity msg) {
    return 0;
}


public List<Msgentity> getAllMsgsList() {
    List<Msgentity> msgList = new ArrayList<Msgentity>();
    DBConnection db= new DBConnection();
    Connection conn = db.getConn();
    try {
        Statement stmt = conn.createStatement();
        String sql="selecr * from msg";
        ResultSet rs = stmt.executeQuery(sql);
        while (rs.next()){
            int id =rs.getInt(1);
            String content = rs.getString(2);
            String author = rs.getString(3);
            String publishtime = rs.getString(4);
            Msgentity msg=new Msgentity(id,content,author,publishtime);
            msgList.add(msg);
        }
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


    return msgList;
}

public Msgentity getOneMsgByid(int id) {
    return null;
}
public static void main(String[] args){
     IMsgDAO dao =new MsgDaoMysqlImpl();
     List<Msgentity> msgs=dao.getAllMsgsList();
     for(Msgentity msg:msgs){
         System.out.println("留言的ID："+msg.getId());
         System.out.println("留言的内容："+msg.getContent());
         System.out.println("留言的作者："+msg.getAnthor());
         System.out.println("留言的发布时间："+msg.getPublishtime());
     }
}

}

Answer 1

你这个是main函数是自己敲的还是建类的时候自动生成的?