Packaging Web Modules

searchcoilSoftware and s/w Development

Aug 15, 2012 (4 years and 10 months ago)

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Packaging Web Modules


To build the
hello1

application with NetBeans IDE, follow these instructions:

1.

Select File→Open Project.

2.

In the Open Project dialog, navigate to:

tut
-
install
/javaeetutorial5/examples/web/

You can download it from here
http://java.net/projects/javaeetutorial/downloads/download/javaeetutorial5.zip



3.

S
elect the
hello1

folder.

4.

Select the Open as Main Project check box.


5.

Click Open Project Folder
.

6.

In the Projects tab, right
-
click the
hello1

project and select Build Project.

Deploying a WAR File


In a packaged web module for deployment on the Application Server, the context root is stored in
sun
-
web.xml
.

To edit the context root, do the following:

1.

Expand your project tree in the Projects pane of NetBeans IDE.

2.

Expand the Web Pages and WEB
-
INF nodes of your project.

3.

Double
-
click
sun
-
web.xml
.

4.

In the editor pane, click Edit As XML.

5.

Edit the context root, which is enclosed by the
context
-
root

element.



To deploy a WAR with NetBeans IDE, do the following
:

1.

Select File→Open Project.

2.

In the Open Project dialog, navigate to your project and open it.

3.

In the Projects tab, right
-
click the project and select Deploy Project.




Updating a Packaged Web Module

This section describes how to update the
hello1

web modu
le that you packaged.

First, change the greeting in the file
tut
-
install
/javaeetutorial5/examples/web/hello1/web/index.jsp

to

<h2>Hi, my name is
Jogi
. What’s yours?</h2>


To update the project in NetBeans IDE:


Right
-
click on the project and select Build Pr
oject.


Right
-
click on the project and select Deploy Project.





Configuring Web Applications


Mapping URLs to Web Components

Setting the Component Alias


The
hello2

application has two servlets that need to be mapped in the
web.xml

file. You can edit a
web
application’s
web.xml

file in NetBeans IDE by doing the following:

1.

Select File→Open Project.

2.

In the Open Project dialog, navigate to:

tut
-
install
/javaeetutorial5/examples/web/

3.

Select the
hello2

folder.

4.

Select the Open as Main Project check box.

5.

Click O
pen Project Folder.

6.

Expand the project tree in the Projects pane.

7.

Expand the Web pages node and then the WEB
-
INF node in the project tree.

8.

Double
-
click the
web.xml

file inside the WEB
-
INF node.



The following steps describe how to make the necessary edit
s to the
web.xml

file, including how to set the
display name and how to map the servlet components. Because the edits are already in the file, you can just
use the steps to view the settings.

To set the display name:

1.

Click General at the top of the editor
to open the general view.

2.

Enter
hello2

in the Display Name field.



To perform the servlet mappings:

1.

Click Servlets at the top of the editor to open the servlets view.

2.

Click Add Servlet.

3.

In the Add Servlet dialog, enter
GreetingServlet

in the Servlet Name

field.

4.

Enter
servlets.GreetingServlet

in the Servlet Class field.

5.

Enter
/greeting

in the URL Pattern field.

6.

Click OK.

7.

Repeat the preceding steps, except enter
ResponseServlet

as the servlet name,
servlets.ResponseServlet

as the servlet class, and
/respons
e

as the URL pattern


To package the example with NetBeans IDE, do the following:



In the Projects tab, right
-
click the
hello2

project and select Build Project.



To deploy the example using NetBeans IDE, right
-
click on the project in the Projects pane and
se
lect Deploy Project.



To run the application, first deploy the web module, and then open the URL
http://localhost:8080/hello2/greeting

in a browser.






Declaring Welcome Files


To specify a welcome file in the web application deployment descriptor using
NetBeans IDE, do the
following:

1.

Open the project if you haven’t already.

2.

Expand the project’s node in the Projects pane.

3.

Expand the Web Pages node and then the WEB
-
INF node.

4.

Double
-
click
web.xml
.

5.

Do one of the following, making sure that the JSP pages you
specify are actually included in the
WAR file:

1.

Click Pages at the top of the editor pane and enter the names of the JSP pages that act

as welcome files in the Welcome Files field.

2.

Click XML at the top of the editor pane, specify the JSP pages using
welcome
-
file

elements and include these elements inside a
welcome
-
file
-
list

element. The
welcome
-
file

element defines the JSP page to be used as the welcome page.




Setting Initialization Parameters


To add a context parameter using NetBeans IDE, do the
following:

1.

Open the project if you haven’t already.

2.

Expand the project’s node in the Projects pane.

3.

Expand the Web Pages node and then the WEB
-
INF node.

4.

Double
-
click
web.xml
.

5.

Click General at the top of the editor pane.

6.

Select the Context Parameters node.

7.

Click Add.

8.

In the Add Context Parameter dialog, do the following:

1.

Enter the name that specifies the context object in the Param Name field.

2.

Enter the parameter to pass to the context object in the Param Value field.

3.

Click OK.

Alternatively, you can edit th
e XML of the
web.xml

file directly by clicking XML at the top of the editor pane
and using the following elements to add a context parameter:


A
param
-
name

element that specifies the context object


A
param
-
value

element that specifies the parameter to pass
to the context object


A
context
-
param

element that encloses the previous two elements

To add a web component initialization parameter using NetBeans IDE, do the following:

1.

Open the project if you haven’t already.

2.

Expand the project’s node in the Projects p
ane.

3.

Expand the Web Pages node and then the WEB
-
INF node.

4.

Double
-
click
web.xml
.

5.

Click Servlets at the top of the editor pane.

6.

After entering the servlet’s name, class, and URL pattern, click the Add button under the
Initialization Parameters table.

7.

In the
Add Initialization Parameter dialog:

1.

Enter the name of the parameter in the Param Name field.

2.

Enter the parameter’s value in the Param Value Field.

3.

Click OK.

Alternatively, you can edit the XML of the
web.xml

file directly by clicking XML at the top of the

editor pane
and using the following elements to add a context parameter:


A
param
-
name

element that specifies the name of the initialization parameter


A
param
-
value

element that specifies the value of the initialization parameter


An
init
-
param

element that

encloses the previous two elements

Mapping Errors to Error Screens


To set up error mappings using NetBeans IDE, do the following:

1.

Open the project if you haven’t already.

2.

Expand the project’s node in the Projects pane.

3.

Expand the Web Pages node and then
the WEB
-
INF node.

4.

Double
-
click
web.xml
.

5.

Click Pages at the top of the editor pane.

6.

Expand the Error Pages node.

7.

Click Add.

8.

In the Add Error Page dialog:

1.

Click Browse to locate the page that you want to act as the error page.

2.

Enter the HTTP status code that will cause the error page to be opened in the Error Code
field.

3.

Enter the exception that will cause the error page to load in the Exception Type field.

4.

Click OK.

Alternatively, you can click XML at the top of the editor pane

and enter the error page mapping by hand
using the following elements:


An
exception
-
type

element specifying either the exception or the HTTP status code that will
cause the error page to be opened.


A
location

element that specifies the name of a web resou
rce to be invoked when the status
code or exception is returned. The name should have a leading forward slash (
/
).


An
error
-
page

element that encloses the previous two elements.