比较老的文章了~不过初学者应该还是有点帮助的~
来自
http://www.laliluna.de/index.htmlThe
example application will provide the following functionality.
Development
Tools
Eclipse
3.x
MyEclipse
plugin 3.8
(A
cheap and quite powerful Extension to Eclipse to develop Web
Applications and EJB (J2EE) Applications. I think that there is a
test version availalable at MyEclipse.)
Application
Server
Jboss
3.2.5
You
may use Tomcat here if you like.
Create a JavaServer faces project
Create a new web project. File
> New > Project.
Set
a nice name and add the JSTL Libraries to the project.
Add
the JavaServer faces Capabilities. Right click on the project and
choose MyEclipse > Add JSF
Capabilities.
The class Book
Add an new package de.laliluna.tutorial.library
und create a new class named Book.
Open the class and add the following private
properties:
Generate a getter- and setter-method for each
property. Right click on the editor window and choose Source
> Generate Getter- and Setter Methods.
Furthermore you have to add a constructor, which
set the properties if you initialisize the instance variable of the
newly object.
The following source code show the class book.
public class Book implements Serializable {
// ------------------ Properties --------------------------------
private long id;
private String author;
private String title;
private boolean available;
// ------------------ Constructors --------------------------------
public Book(){}
public Book(long id, String author, String title, boolean available){
this.id = id;
this.author = author;
this.title = title;
this.available = available;
}
// ------------------ Getter and setter methods ---------------------
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public boolean isAvailable() {
return available;
}
public void setAvailable(boolean available) {
this.available = available;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
Add a getter and setter for the class.
/**
* Set the properties
* @param book
*/
public void setBook(Book book){
this.setId(book.getId());
this.setAuthor(book.getAuthor());
this.setTitle(book.getTitle());
this.setAvailable(book.isAvailable());
}
/**
* @return book object
*/
public Book getBook(){
return new Book(this.getId(),
this.getAuthor(),
this.getTitle(),
this.isAvailable());
}
The database class
We use a class to provide some test data
without using a database. Download the sample application of this
tutorial and copy the class SimulateDB.java
find in the folder src/de/laliluna/tutorial/library/
in the package
de.laliluna.tutorial.library.
The class BookList
Create a futher class BookList
in the package de.laliluna.library.
This class inlcudes the property books, which represent the list of
books. Generate a getter- and seter-method for the property books
and change the getter-method like the following.
public class BookList {
// ------------------------- Properties ---------------------------
Collection books;
// ------------------------- Getter and Setter --------------------
/**
* @return collection of books
*/
public Collection getBooks(){
SimulateDB simulateDB = new SimulateDB();
/* Holt sich die Session auf dem Externen Context
*/
Map session = FacesContext.getCurrentInstance().getExternalContext().getSessionMap();
/* Lies alle Bücher auf der simulierten Datenbank aus
*/
books = simulateDB.getAllBooks(session);
return books;
}
/**
* @param books The books to set.
*/
public void setBooks(Collection books) {
this.books = books;
}
}
Your package
explorer will look like the picture below.
Action listener methods
To provide that a user can add, edit or
delete a book, we have to include the appropriate functionality. This
functionality will be implemented in action listener methods /
classes. If an event occur (ex.: a user clicks on a link) an action
listener method / class will be called and processed.
Open the class Book and add four methods ,
which process the following functionality.
Initializise a book
Edit a book
Save a book
Delete a book
Initialize a book
/**
* Initial the properties of the class with null
* @param event
*/
public void initBook(ActionEvent event){
/*
* init the book object
*/
this.setBook(new Book());
}
Edit a book
/**
* Get the book to edit and assign it to the bean
*
* @param event
*/
public void selectBook(ActionEvent event){
SimulateDB simulateDB = new SimulateDB();
/*
* Get the session map of the external context
*/
Map session = FacesContext.getCurrentInstance().getExternalContext().getSessionMap();
/*
* Find the UIParameter component by expression
*/
UIParameter component = (UIParameter) event.getComponent().findComponent("editId");
/*
* parse the value of the UIParameter component
*/
long id = Long.parseLong(component.getValue().toString());
/*
* get the book by id and set it in the local property
*/
this.setBook(simulateDB.loadBookById(id, session));
}
Save a book
/**
* Add or update the book in the simulated database.
* If the book id is not set the book will be added
* otherwise the book will be updated
*
* @param event
*/
public void saveBook(ActionEvent event){
SimulateDB simulateDB = new SimulateDB();
/*
* Get the session map of the external context
*/
Map session = FacesContext.getCurrentInstance().getExternalContext().getSessionMap();
/*
* Add or update the book in the simulated database
*/
simulateDB.saveToDB(this.getBook(), session);
}
Delete a book
/**
* Delete a book in the simulated database
*
* @param event
*/
public void deleteBook(ActionEvent event){
SimulateDB simulateDB = new SimulateDB();
/*
* Get the session map of the external context
*/
Map session = FacesContext.getCurrentInstance().getExternalContext().getSessionMap();
/*
* Find the UIParameter component by expression
*/
UIParameter component = (UIParameter) event.getComponent().findComponent("deleteId");
/*
* parse the value of the UIParameter component
*/
long id = Long.parseLong(component.getValue().toString());
/*
* delete the book by id
*/
simulateDB.deleteBookById(id, session);
}
The file
faces-config.xml
The faces-config.xml is the central
configuration file of JavaServer faces. In this file you define the
workflow of the application (on which action which site will be
processed) , the managed bean classes by JSF and something more.
The workflow of the library application
looks like the following.
We define a navigation rule for this
workflow.
Open the file faces-config.xml
and add the following configuration.
<faces-config>
<!-- Navigation rules -->
<navigation-rule>
<description>List of books</description>
<from-view-id>/listBooks.jsp</from-view-id>
<navigation-case>
<from-outcome>editBook</from-outcome>
<to-view-id>/editBook.jsp</to-view-id>
</navigation-case>
</navigation-rule>
<navigation-rule>
<description>Add or edit a book</description>
<from-view-id>/editBook.jsp</from-view-id>
<navigation-case>
<from-outcome>listBooks</from-outcome>
<to-view-id>/listBooks.jsp</to-view-id>
<redirect/>
</navigation-case>
</navigation-rule>
</faces-config>
<navigation-rule>
Define a navigation rule
<from-view-id>/listBooks.jsp</from-view-id>
Define the jsp file for which the containing navigation rule is relevant.
<navigation-case>
Define a navigation case
<from-outcome>editBook</from-outcome>
Define a name for this navigation case
<to-view-id>/listBooks.jsp</to-view-id>
Refers to the setted JSP File
<redirect/>
All parameters saved in the request will be losed when you set this tag.
If you want to access the bean classes in your JSP files, you have to register the bean classes in faces-config.xml
Add the following source code.
<!-- Managed beans -->
<managed-bean>
<description>
Book bean
</description>
<managed-bean-name>bookBean</managed-bean-name>
<managed-bean-class>de.laliluna.tutorial.library.Book</managed-bean-class>
<managed-bean-scope>request</managed-bean-scope>
</managed-bean>
<managed-bean>
<description>
BookList Bean
</description>
<managed-bean-name>bookListBean</managed-bean-name>
<managed-bean-class>de.laliluna.tutorial.library.BookList</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
<managed-bean>
Define a managed bean
<managed-bean-name>bookBean</managed-bean-name>
Define a name for the managed bean. This name is used in the JSP file.
<managed-bean-class>de.laliluna.tutorial.library.Book</managed-bean-class>
Define the class which represent the bean.
<managed-bean-scope>request</managed-bean-scope>
Define in which scope the bean is saved.
Create the JSP files
In the first step we create a JSP file named
index.jsp, which forwards
the user to the list of books.
index.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
<jsp:forward page="/listBooks.faces" />
</body>
</html>
In the second step we create the book overview.
listBooks.jsp
<%@ page language="java" %>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>List of books</title>
</head>
<body>
<f:view>
<h:form id="bookList">
<h:dataTable id="books"
value="#{bookListBean.books}"
var="book"
border="1">
<h:column>
<f:facet name="header">
<h:outputText value="Author"/>
</f:facet>
<h:outputText value="#{book.author}" />
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Title"/>
</f:facet>
<h:outputText value="#{book.title}" />
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Available"/>
</f:facet>
<h:selectBooleanCheckbox disabled="true"
value="#{book.available}" />
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Edit"/>
</f:facet>
<h:commandLink id="Edit"
action="editBook"
actionListener="#{bookBean.selectBook}">
<h:outputText value="Edit" />
<f:param id="editId"
name="id"
value="#{book.id}" />
</h:commandLink>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Delete"/>
</f:facet>
<h:commandLink id="Delete"
action="listBooks"
actionListener="#{bookBean.deleteBook}">
<h:outputText value="Delete" />
<f:param id="deleteId"
name="id"
value="#{book.id}" />
</h:commandLink>
</h:column>
</h:dataTable>
<h:commandLink id="Add"
action="editBook"
actionListener="#{bookBean.initBook}">
<h:outputText value="Add a book" />
</h:commandLink>
</h:form>
</f:view>
</body>
</html>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
With directive taglib
we include the JSF tag libraries
<f:view>
Renders a view component. All others tags must be included within
this tag.
<h:form id="bookList">
Renders a HTML form.
<h:dataTable id="books" value="#{bookListBean.books}" var="book" border="1">
Renders a HTML table. The tag is used to loop over a list of data
like a for loop. The
parameter value assign a
list of data, in our case the list of books of the library. With the
parameter var you define
the variable used to access a element (a book) of the list within the
tag (loop).
<h:column>
<f:facet name="header">
<h:outputText value="Author"/>
</f:facet>
<h:outputText value="#{book.author}" />
</h:column>
Renders a column with a column header.
<f:facet name="header"> display the header.
<h:outputText value="Author"/> print out a header label.
<h:outputText value="#{book.author}" /> refers to the property author of the current element of the list.
<h:commandLink id="Edit"
action="editBook"
actionListener="#{bookBean.selectBook}">
Renders a HTML link, which submits the form. The parameter action
define the navigation case, which is processed, after the form
submits In our case the navigation case editBook, we have added befor
in the faces-config.xml, will be processed. We assign the action
listener method to the link with the parameter actionListener.
After the user submit the form the method will be processed.
The last JSP file includes a form to add and
edit a book.
editBook.jsp
<%@ page language="java" %>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>Add / Edit a book</title>
</head>
<body>
<f:view>
<h:form>
<h:inputHidden id="id" value="#{bookBean.id}"/>
<h:panelGrid columns="2" border="1">
<h:outputText value="Author:" />
<h:inputText id="author"
value="#{bookBean.author}">
</h:inputText>
<h:outputText value="Title:" />
<h:inputText id="title"
value="#{bookBean.title}">
</h:inputText>
<h:outputText value="Available:" />
<h:selectBooleanCheckbox id="available"
value="#{bookBean.available}" />
</h:panelGrid>
<h:commandButton value="Save"
action="listBooks"
actionListener="#{bookBean.saveBook}" />
</h:form>
</f:view>
</body>
</html>
<h:inputHidden id="id" value="#{bookBean.id}"/>
Renders a HTML hidden element. Value refers to the managed bean
bookBean and its property
id, which indicated in the
faces-config.xml.
<h:panelGrid columns="2" border="1">
Renders a HTML table with two columns.
<h:inputText id="author" value="#{bookBean.author}">
Renders a HTML text field. Value refers to the property author
of our class Book.
<h:commandButton value="Save"
action="listBooks"
actionListener="#{bookBean.saveBook}" />
Renders a HTML submit button with the value save and the action
listBooks. The action listener method saveBook
will be processed if the user submit the form.
Test the application
Start the jboss and deploy the project as
Packaged Archive.
Call the project now
http://localhost:8080/LibraryWeb/
Author:
Sascha
Wolski
http://www.laliluna.de/tutorials.html
Tutorials for Struts, EJB, xdoclet, JSF, JSP and eclipse.