个回答

• 模棱0

  2016-10-26 21:53:41

  req.setCharacterEncoding("utf-8");

  try {

  String command = req.getParameter("command");

  String description = req.getParameter("description");

  req.setAttribute("command", command);

  req.setAttribute("description", description);

  Class.forName("com.mysql.jdbc.Driver");

  Connection connection = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/micro_message", "root", "root");

  StringBuilder sql = new StringBuilder("select ID,COMMAND,DESCRIPTION,CONTENT from MESSAGE where 1=1");

  List<String> paramList = new ArrayList<String>();

  if (command != null && !"".equals(command.trim())) {

  sql.append(" and COMMAND = ?"); //先把拼接的模版做好，最后在通过%把传过来的参数加进去

  paramList.add(command);

  }                    

  if (description != null && !"".equals(description.trim())) {

  sql.append(" and DESCRIPTION like '%' ? '%'");

  paramList.add(description);

  }

  PreparedStatement statement = (PreparedStatement) connection.prepareStatement(sql.toString());

  System.out.println(paramList.size());

  for (int i = 0; i < paramList.size(); i++) {

  statement.setString(i+1, paramList.get(i));//sql语句中出现的？是从第一个开始数

  }

  System.out.println(sql.toString());

  ResultSet resultSet = statement.executeQuery();

  List<Message> messageList = new ArrayList<Message>();

  while(resultSet.next()){

  Message message = new Message();

  messageList.add(message);

  message.setId(resultSet.getString("ID"));

  //System.out.println(resultSet.getString("ID"));

  message.setCommand(resultSet.getString("COMMAND"));

  message.setDescription(resultSet.getString("DESCRIPTION"));

  message.setContent(resultSet.getString("CONTENT"));

  }

  req.setAttribute("messageList", messageList);

  
  

  0

• qq_我不高兴了_03822679

  2016-10-25 11:01:54

  把代码贴出来

  0