我正在研究一个小型消息传递Web应用程序以学习jsp和servlet。我有一个具有以下属性的MessageModel类:即使出现getter时也会出现PropertyNotFoundException
String toAddress ;
String fromAddress;
String messageSubject;
String messageContent;
Timestamp messageTime;
int messageDraft;
以及它们对应的setter,供jsp访问。
我有一个方法,查询数据库的所有消息,收到消息接收到特定的地址显示。然后它创建一个新的对象并将其存储在ArrayList中。
public static ArrayList<MessageModel> getReceivedMessages(String toAddress) throws SQLException, ClassNotFoundException{
// creates a arraylist.
ArrayList<MessageModel> msgList = new ArrayList<MessageModel>();
// Database connection code..
// The query which gets the required messages from the database and adds them to the list.
String query = "SELECT * FROM messages WHERE msg_to='" + toAddress +"' ORDER BY msg_date DESC";
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(query);
if(rs.next()){
while(rs.next()){
String msgTo = rs.getString("msg_to");
String msgFrom = rs.getString("msg_from");
String msgSub = rs.getString("msg_subject");
String msgCnt = rs.getString("msg_matter");
Timestamp msgTime = rs.getTimestamp("msg_date");
MessageModel model = new MessageModel(msgTo,msgFrom,msgSub,msgCnt,msgTime);
msgList.add(model);
}
}
return msgList;
}
我打电话从JSP此方法,并通过使用
String userName = (String) session.getAttribute("userId");
ArrayList<MessageModel> list = MessageModel.getReceivedMessages(userName);
pageContext.setAttribute("messageList", list);
列表保存为一个属性,但是当我通过<c:forEach>
标签访问该列表中的MesasgeModel对象的FROMADDRESS财产,我出现以下错误:
javax.el.PropertyNotFoundException: Property 'fromAddress' not found on type com.email.system.MessageModel
这是访问打印出每个MessageModel
对象的内容的HTML的一部分。
<c:forEach items="${messageList}" var="message">
<li><c:out value="${message.toAddress}"/>
<c:out value="${message.messageSubject}"/> <c:out value="${message.messageTime}"/>
<c:out value="${message.messageContent}"/> <c:out value="${message.fromAddress}"/> </li>
</c:forEach>
每当我尝试访问toAddress
字段时都会发生错误。 toAddress属性被存储在messageSubject
字段中,即使当我在mySql控制台中尝试相同的查询时,我也会在它们各自的列中获取正确的字段。
的exapmle结果到我删除了内容列的查询,
msg_id msg_to msg_from msg_subject msg_date msg_is_draft
4 bigb remember *subject* 2014-10-07 11:01:53 0
2 bigb remember *subject* 2014-10-07 10:48:43 0
1 bigb remember *subject* 2014-10-07 10:48:31 0
编辑:这是MessageModel
类我。
public class MessageModel {
String toAddress ;
String fromAddress;
String messageSubject;
String messageContent;
Timestamp messageTime;
int messageDraft;
public String getToAddress() {
return toAddress;
}
public String getFromAddress() {
return fromAddress;
}
public String getMessageSubject() {
return messageSubject;
}
public String getMessageContent() {
return messageContent;
}
public Timestamp getMessageTime() {
return messageTime;
}
public int getMessageDraft() {
return messageDraft;
}
public MessageModel(String toAddress,String fromAddress, String messageSubject, String messageContent,Timestamp messageTime){
this.toAddress = toAddress;
this.messageSubject = messageSubject;
this.messageContent = messageContent;
this.messageTime = messageTime;
this.fromAddress = fromAddress;
}
public void sendMessage(MessageModel model){
//Gets the related properties from the objects and stores it in the database
}
public static ArrayList<MessageModel> getReceivedMessages(String toAddress){
//Gets the messages sent to 'toAddress'
}
}
发布您的'MessageModel'类。这些属性来自getter/setters而不是来自field的名称。所以你应该有'toAddress'属性的'getToAddress()'方法。 – 2014-10-07 06:19:38
我使用intelliJ,我使用代码插入工具来创建类的setter。我理解一个jsp如何根据另一个SO问题的JavaBeans规范来要求这些。 – Bhargav 2014-10-07 06:26:56
一如既往的这些问题,尝试一个完整的清理,重建,重新部署。 – Magnilex 2014-10-07 06:31:29