Loops 如何在JSF网页上显示Bean中的项目列表?
我是JSF新手,正在学习im构建在线书店应用程序 我有一个类和一个bean:Loops 如何在JSF网页上显示Bean中的项目列表?,loops,jsf,jsf-2,collections,iteration,Loops,Jsf,Jsf 2,Collections,Iteration,我是JSF新手,正在学习im构建在线书店应用程序 我有一个类和一个bean:Book.java和BookCatelogBean.java。Book类有3个属性:id,title,和author,以及相应的getter和setter。BookCatelogBean包含一个ArrayList,我在其中填充了Books(将来我将把它连接到数据库) 我有两个页面:index.xhtml和book.xhtml。我想在index.xhtml上显示书籍标题列表,每个标题都格式化为REST链接,并且它们的ID指
Book.java
和BookCatelogBean.java
。Book类有3个属性:id
,title
,和author
,以及相应的getter和setter。BookCatelogBean
包含一个ArrayList
,我在其中填充了Books
(将来我将把它连接到数据库)
我有两个页面:index.xhtml
和book.xhtml
。我想在index.xhtml
上显示书籍标题列表,每个标题都格式化为REST链接,并且它们的ID指向book.xhtml
,如下所示:
我知道如何使用BookCatelogBean
显示1book
,但我想显示所有这些?我想从BookCatelogBean
调用一个名为getAllBooks()
的方法,该方法返回每本书的标题,但如何将它们作为JavaserverFace链接而不是字符串返回到index.xhtml
谢谢
这是我的密码:
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;
}
}
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();
}
}
BookCatelogBean.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;
}
}
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();
}
}
包装书店;
导入java.io.Serializable;
导入java.util.ArrayList;
导入java.util.array;
导入javax.faces.bean.ManagedBean;
导入javax.faces.bean.SessionScoped;
@ManagedBean
@会议范围
公共类BookCatelogBean实现了可序列化{
private int currentItem=0;
private ArrayList books=new ArrayList(Arrays.asList(
新书(1,《货币和信用理论》,《路德维希·冯·米塞斯》),
新书(2,《人、经济和国家》,《莫里·罗斯巴德》),
新书(3,《实时关系》,《斯特凡·莫利纽斯》);
公共字符串getTitle(){
return books.get(currentItem).getTitle();
}
公共int getId(){
return books.get(currentItem).getId();
}
公共字符串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>
书店
JSF2提供了两个现成的迭代组件:和。前者不向响应呈现任何内容(因此您对最终HTML输出拥有100%的控制权),而后者向响应呈现HTML
,并且需要一个表示
的列。这两个组件都可以将列表
作为值
因此,您可以使用托管bean,如下所示:
@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;
}
}
至于JSTL
,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组件不同。长话短说:
另见:
Link:这里需要的是c:forEach吗?我尝试了上面的代码,得到了一个显然是空的列表。我可能做错了什么?我收回上述问题。