我有一个包含列表的 DTO。当用户单击添加按钮时，我想向数据表添加新行。但是当我单击添加dto 时，即调用构造函数并初始化值并且列表大小为 0。该 bean 是对话范围的。在使用对话范围 bean 时，我应该开始和结束相同视图的对话吗？我正在使用相同的 bean 进行编辑，它运行良好。如何在使用 Richfaces 4 和 jsf 2 和 ajax 时解决初始化问题。
看法：
<rich:panel id ="dataPnl">
<rich:dataTable value="#{legendbean.legendDTO.list}" var="legend" style="width:100%">
<rich:column>
<f:facet name="header">
<h:outputText value="SN"/>
</f:facet>
<h:inputText value="#{legend.sn}"/>
</rich:column>
<rich:column>
<f:facet name="header">
<h:outputText value="Description"/>
</f:facet>
<h:inputText value="#{legend.desc}"/>
</rich:column>
<rich:column>
<a4j:commandLink value="Add" actionListener="#{legendbean.addLegendRange()}" render="nisForm:dataPnl"/>
<h:outputText value=" / "/>
<a4j:commandLink value="Remove" actionListener="#{legendbean.removeLegendRange(legend)}" render="nisForm:dataPnl"/>
</rich:column>
</rich:dataTable>
</rich:panel>
豆 ：
@Named("legendbean")
@ConversationScoped
public class LegendController implements Serializable {
LegendDTO legendDTO = new LegendDTO();
String selectedLegend;
boolean edit;
@Inject
private Conversation conversation;
public boolean isEdit() {
return edit;
}
public void setEdit(boolean edit) {
this.edit = edit;
}
public LegendController() {
Logger.getLogger(LegendController.class.getName()).warning("The value of Edit is : " + edit);
if (!edit) {
legendDTO.getList().add(new Legend());
Logger.getLogger(LegendController.class.getName()).warning("The size of list" + legendDTO.getList().size());
}
}
public LegendDTO getLegendDTO() {
return legendDTO;
}
public void setLegendDTO(LegendDTO legendDTO) {
this.legendDTO = legendDTO;
}
public void addLegendRange() {
Logger.getLogger(LegendController.class.getName()).warning("List Size " + legendDTO.getList().size());
legendDTO.getList().add(new Legend());
Logger.getLogger(LegendController.class.getName()).warning("List Size " + legendDTO.getList().size());
}
public void removeLegendRange(Legend legend) {
if (legendDTO.getList().size() != 1) {
legendDTO.getList().remove(legend);
}
}
public String saveLegend() {
Logger.getLogger(LegendController.class.getName()).warning("Save Legend Edit" + edit);
LegendDAO dao = new LegendDAO();
if (dao.addLegend(legendDTO, edit)) {
if (edit) {
conversation.end();
edit = false;
Logger.getLogger(LegendController.class.getName()).warning("Save Legend Edit" + edit);
return "VIEWLEGEND";
} else {
legendDTO = new LegendDTO();
legendDTO.getList().add(new Legend());
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Saved !"));
return "";
}
} else {
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Could Not Save Confim if you have already defined Legend " + legendDTO.getLegendName() + "!"));
return "";
}
}
public List<LegendDTO> getLegends() {
LegendDAO dao = new LegendDAO();
return dao.getLegendDTO();
}
//All function from here are for legend delete
public void deleteLegendType(LegendDTO dto) {
LegendDAO dao = new LegendDAO();
if (dao.deleteLegendType(dto.getLegendName())) {
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Deleted !"));
} else {
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Deleted Error !"));
}
}
//All function from here is to legend edit
public String editLegendType(LegendDTO dto) {
conversation.begin();
edit = true;
legendDTO = dto;
LegendDAO dao = new LegendDAO();
dto.getList().clear();
try {
List<Legend> legends = dao.getDetailForEditLegend(dto.getLegendName());
dto.setList(legends);
} catch (SQLException ex) {
Logger.getLogger(LegendController.class.getName()).warning("SQL EXception has occoured");
}
Logger.getLogger(LegendController.class.getName()).warning("The size of list" + dto.getList().size());
return "addLegend";
}
public String cancel() {
conversation.end();
return "VIEWLEGEND";
}
}