如何将Bean中的项目列表显示到JSF网页上?

问题描述 投票:16回答:2

我是JSF的新手,正在学习建立一个在线书店应用程序的过程。

我有1个类别和1个bean:Book.javaBookCatelogBean.java。 Book类具有3个属性:idtitleauthor,以及相应的getter和setter。 BookCatelogBean包含一个ArrayList<Book>,并在其中填充Books(以后我将其连接到数据库)。

我有两页:index.xhtmlbook.xhtml。我想在index.xhtml上显示每个书名的列表,每个书名都设置为REST链接,其ID指向book.xhtml,如下所示:<h:link outcome="book?id=#{bookCatelogBean.id}" value="#{bookCatelogBean.title}" />

我知道如何使用BookCatelogBean显示1 book,但我想全部显示?我有一个想法,可以从BookCatelogBean中调用一个名为getAllBooks()的方法,该方法返回每本书的书名,但是如何将每本书的书名作为JavaserverFace链接而不是字符串返回给index.xhtml?

谢谢

这是我的代码:

Book.java

package bookshop;

import java.io.Serializable;

public class Book implements Serializable {

    private int id;
    private String title;
    private String author;

    public Book(int id, String title, String author){
        this.title = title;
        this.id = id;
        this.author = author;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

BookCatelogBean.java

package bookshop;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

@ManagedBean
@SessionScoped
public class BookCatelogBean implements Serializable {
    private int currentItem = 0;

    private ArrayList<Book> books = new ArrayList<Book>(Arrays.asList(
            new Book(1, "Theory of Money and Credit", "Ludwig von Mises"),
            new Book(2, "Man, Economy and State", "Murry Rothbard"),
            new Book(3, "Real Time Relationships", "Stefan Molyneux")));

    public String getTitle(){
        return books.get(currentItem).getTitle();
    }

    public int getId(){
        return books.get(currentItem).getId();
    }

    public String getAuthor(){
        return books.get(currentItem).getAuthor();
    }

}

index.xhtml

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html">
    <h:head>
        <title>BookShop</title>

    </h:head>
    <h:body>
        <h:link outcome="book?id=#{bookCatelogBean.id}" value="#{bookCatelogBean.title}" />
    </h:body>
</html>
loops jsf jsf-2 collections iteration
2个回答
32
投票

JSF2提供了两个迭代组件:<ui:repeat><ui:repeat>。前者不对响应进行任何渲染(因此您可以对最终的HTML输出进行100%的控制),而后者则对响应进行HTML <h:dataTable>的渲染,并需要<h:dataTable>来表示<table>的列。这两个组件都可以取<h:column>作为值。

因此,您可以像下面这样放置您的托管bean:

<h:column>

并且您可以使用<td>生成例如List<E>

@ManagedBean
@RequestScoped
public class BookCatalog implements Serializable {

    private List<Book> books;

    @PostConstruct
    public void init() {
        books = new ArrayList<Book>();
        books.add(new Book(1, "Theory of Money and Credit", "Ludwig von Mises"));
        books.add(new Book(2, "Man, Economy and State", "Murry Rothbard"));
        books.add(new Book(3, "Real Time Relationships", "Stefan Molyneux"));
    }

    public List<Book> getBooks() {
        return books;
    }

}

(请注意,<ui:repeat>属性基本上通过组件内EL范围内的给定名称公开当前迭代的项目。

这是使用<ul><li>的替代方法:

<ul>
    <ui:repeat value="#{bookCatalog.books}" var="book">
        <li>
            <h:link value="#{book.title}" outcome="book">
                <f:param name="id" value="#{book.id}" />
            </h:link>
        </li>
    </ui:repeat>
</ul>

对于JSTL var,这也是很有可能的,但是您应该记住,JSTL标记的生命周期与JSF组件的生命周期不同。长话短说:<h:dataTable>

另请参见:

  • <h:dataTable value="#{bookCatalog.books}" var="book"> <h:column> <h:link value="#{book.title}" outcome="book"> <f:param name="id" value="#{book.id}" /> </h:link> </h:column> </h:dataTable>
  • <c:forEach>
  • JSTL in JSF2 Facelets... makes sense?

1
投票

您也可以使用PrimeFaces库

链接:How to choose the right bean scope?

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