我已經搜索了這個,我仍然無法找到正確的答案。我試圖從數據庫中取回數據,並將一堆對象添加到ArrayList中。我的IDE告訴我,messages.add(objMessage)行中的objMessage無法解析爲變量。爲什麼當我在我的函數開頭聲明ArrayList消息= null時,它告訴我這一點?獲取Java錯誤無法解析到變量
謝謝!
ArrayList<Message> messages = null;
try {
sqlConn = ds.getConnection();
sqlConnector = new SQLConnector(sqlConn);
String sql = "SELECT * FROM table WHERE thing = 1;";
rs = sqlConnector.getData(sql);
while(rs.next()) {
String stuff = rs.getString("stuff");
if(stuff.toUpperCase().contains(stuff.toUpperCase())) {
int id = rs.getInt("id");
String data = rs.getString("data");
Date time = rs.getDate("time");
Message objMessage = new Message(id, time, data);
}
messages.add(objMessage);
}
catch(Exception e) {
// catch exception
}
你正在將'messages'初始化爲'null' ......至少,實例化應該是:'ArrayList messages = new ArrayList <>();' –
Barranka
2014-09-04 23:44:12