页面配置文件中定义了对话的flush模式

<begin-conversation join="true" flush-mode="MANUAL"/>

代码里必须主动调用em.flush();，否则不会更新数据库

public void updateJgdwGN(Jgdwjbxxb jgdw,List<TreeNodeVO> gns){         em.createQuery("delete JsfjgnlbENT u where u.jgdw=:jgdw").setParameter("jgdw", jgdw).executeUpdate();         for(TreeNodeVO item:gns){             XtgnbENT xtgn=(XtgnbENT)item.getData();                         if(xtgn.isSffjgn()){                 JsfjgnlbENT up=new JsfjgnlbENT();                 up.setJgdw(jgdw);                 up.setGn(xtgn);                 em.persist(up);             }         }         em.flush();     }

pages.java

private static void parseConversationControl(Element element, ConversationControl control){

Element beginConversation = element.element("begin-conversation");       beginConversation = beginConversation == null ? element.element("begin-task") : beginConversation;       beginConversation = beginConversation == null ? element.element("start-task") : beginConversation;       if ( beginConversation!=null )       {          control.setBeginConversation (true);          control.setJoin( Boolean.parseBoolean( beginConversation.attributeValue("join") ) );          control.setNested( Boolean.parseBoolean( beginConversation.attributeValue("nested") ) );          control.setPageflow( beginConversation.attributeValue("pageflow") );          control.setConversationName( beginConversation.attributeValue("conversation") );          String flushMode = beginConversation.attributeValue("flush-mode");          if (flushMode!=null)          {             control.setFlushMode ( FlushModeType.valueOf( flushMode.toUpperCase() ) );          }          String expression = beginConversation.attributeValue("if");          if (expression!=null)          {             control.setBeginConversationCondition( Expressions.instance().createValueExpression(expression, Boolean.class) );          }

ConversationControl

/*

Demarcation of the conversation in pages.xml

*/

package org.jboss.seam.navigation;

public class ConversationControl