使用JSF 2.0提供的标准功能，CRUD确实是小菜一碟：@ViewScoped结合了一个bean
Bean:：
package com.example;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.postconstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
@ManagedBean
@ViewScoped
public class Bean implements Serializable {
private List<Item> list;
private Item item = new Item();
private boolean edit;
@postconstruct
public void init() {
// list = dao.list();
// Actually, you should retrieve the list from DAO. This is just for demo.
list = new ArrayList<Item>();
list.add(new Item(1L, "item1"));
list.add(new Item(2L, "item2"));
list.add(new Item(3L, "item3"));
}
public void add() {
// dao.create(item);
// Actually, the DAO should already have set the ID from DB. This is just for demo.
item.setId(list.isEmpty() ? 1 : list.get(list.size() - 1).getId() + 1);
list.add(item);
item = new Item(); // Reset placeholder.
}
public void edit(Item item) {
this.item = item;
edit = true;
}
public void save() {
// dao.update(item);
item = new Item(); // Reset placeholder.
edit = false;
}
public void delete(Item item) {
// dao.delete(item);
list.remove(item);
}
public List<Item> getList() {
return list;
}
public Item getItem() {
return item;
}
public boolean isEdit() {
return edit;
}
// Other getters/setters are actually unnecessary. Feel free to add them though.
}
Page：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
<title>Really simple CRUD</title>
</h:head>
<h:body>
<h3>List items</h3>
<h:form rendered="#{not empty bean.list}">
<h:dataTable value="#{bean.list}" var="item">
<h:column><f:facet name="header">ID</f:facet>#{item.id}</h:column>
<h:column><f:facet name="header">Value</f:facet>#{item.value}</h:column>
<h:column><h:commandButton value="edit" action="#{bean.edit(item)}" /></h:column>
<h:column><h:commandButton value="delete" action="#{bean.delete(item)}" /></h:column>
</h:dataTable>
</h:form>
<h:panelGroup rendered="#{empty bean.list}">
<p>Table is empty! Please add new items.</p>
</h:panelGroup>
<h:panelGroup rendered="#{!bean.edit}">
<h3>Add item</h3>
<h:form>
<p>Value: <h:inputText value="#{bean.item.value}" /></p>
<p><h:commandButton value="add" action="#{bean.add}" /></p>
</h:form>
</h:panelGroup>
<h:panelGroup rendered="#{bean.edit}">
<h3>Edit item #{bean.item.id}</h3>
<h:form>
<p>Value: <h:inputText value="#{bean.item.value}" /></p>
<p><h:commandButton value="save" action="#{bean.save}" /></p>
</h:form>
</h:panelGroup>
</h:body>
</html>
此外，Netbeans具有一些有用的向导，可基于数据模型生成CRUD应用程序。
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