package?Servlet;

import?java.io.IOException;
import?java.io.PrintWriter;
import?java.sql.Connection;
import?java.sql.DriverManager;
import?java.sql.PreparedStatement;
import?java.sql.ResultSet;
import?java.sql.SQLException;
import?java.util.ArrayList;
import?java.util.List;

import?javax.servlet.ServletException;
import?javax.servlet.http.HttpServlet;
import?javax.servlet.http.HttpServletRequest;
import?javax.servlet.http.HttpServletResponse;

import?bean.Message;

@SuppressWarnings({?"serial",?"unused"?})
public?class?ListServlet?extends?HttpServlet?{

	private?static??String?url?=?"jdbc:MYSQL://127.0.0.1:3306/micro_message";
	private?static??String?user?=?"root";
	private?static??String?password?=?"123456";

	/**
	?*?Constructor?of?the?object.
	?*/
	public?ListServlet()?{
		super();
	}

	public?void?destroy()?{
		super.destroy();?//?Just?puts?"destroy"?string?in?log
		//?Put?your?code?here
	}

	
	public?void?doGet(HttpServletRequest?request,?HttpServletResponse?response)
			throws?ServletException,?IOException?{
		try?{
			Class.forName("com.mysql.jdbc.Driver");
			Connection?conn?=?null;
			try?{
				?request.setCharacterEncoding("utf-8");
				?response.setCharacterEncoding("utf-8");
				?String?command=request.getParameter("command");
				?String?description=request.getParameter("description");
				?request.setAttribute("command",?command);
				?request.setAttribute("description",?description);
				?conn?=?DriverManager.getConnection(url,user,password);
				?StringBuilder?sql=new?StringBuilder("select?*?from?message?where?1=1");
				?List<String>?paramList=new?ArrayList<String>();
				?if(command!=null&&!"".equals(command.trim())){
					?sql.append("?and?command='"+command+"'?");
					?paramList.add(command);
				?}
				?if(description!=null&&!"".equals(description.trim())){
					?sql.append("?and?DESCRIPTION?like?'%'???'%'");
					?paramList.add(description);
				?}
				?PreparedStatement?statement=conn.prepareStatement(sql.toString());
				?for(int?i?=?1;i<paramList.size();i++){
					?statement.setString(i,?paramList.get(i));
				?}
				?ResultSet?rs=statement.executeQuery(sql.toString());
				?List<Message>?messageList=new?ArrayList<Message>();
				?while(rs.next()){
					?Message?message=new?Message();
					?message.setId(rs.getInt("id"));
					?message.setCommand(rs.getString("command"));
					?message.setContent(rs.getString("content"));
					?message.setDescription(rs.getString("description"));
					?messageList.add(message);
				?}
				?request.setAttribute("messageList",?messageList);
			}?catch?(SQLException?e)?{
				e.printStackTrace();
			}
			}?catch?(ClassNotFoundException?e)?{
				e.printStackTrace();
		}
		request.getRequestDispatcher("/WEB-INF/jsp/back/List.jsp").forward(request,?response);
	}

	public?void?doPost(HttpServletRequest?request,?HttpServletResponse?response)
			throws?ServletException,?IOException?{
		this.doGet(request,?response);
	}

	public?void?init()?throws?ServletException?{
		//?Put?your?code?here
	}

}

報錯是?You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '? '%'' at line 1