摘要:
DLQ-死信队列(Dead LetterQueue)用来保存处理失败或者过期的消息。出现以下情况时,消息会被redeliveredA transacted session is used and rollback() is called.A transacted session is closed before commit is called.A session is using CLIENT_ACKNOWLEDGE and Session.recover() iscalled.当一个消息被redelivered超过maximumRedeliveries(缺省为6次,具体设置请参考后面的链接 阅读全文
摘要:
1.关于1...n的全排列。比如:1,2,3的全排列为123,132,213,231,312,321public class Test { public static void main(String[] args) throws Exception { String[] array = new String[] { "1", "2","3"}; int length=array.length; listAll(Arrays.asList(array), "",length); } public static vo 阅读全文