PrimeFaces dataTable column commandButton.update 问题： <p:messages id="msg" /> <p:dataTable> <h:column> <p:commandButton update="msg" /> </h:column> </p:dataTable> 123456 <p:messages id="msg" /><p:dataTable><h:column><p:commandButton update="msg" /></h:column></p:dataTable> 提示 找不到 msg 解决： [cr… Read More
JPA 事务中的自增id 问题： 代码如下，e1.getId() 不行 EntityManager em = **** EntityTransaction trans = em.getTransaction(); trans.begin(); em.persistence(e1); System.out.println(e1.getId());//not work e1. getId() is null e2.referId=e1.getId(); em.persistence(e2); trans.commit(); 12345678 EntityManager em = ****EntityTransaction trans = em.getTransaction();trans.begin();em.persistence(e1);System.out.println(e1.getId());//not work e1. getId() is nulle2.referId=e1.getId();em.persistence(e2);trans.commit(); … Read More