1. Java
EE
Servlet/JSP
Tutorial
Second cookbook, getting started with Model 2: Servlet and JSP
Implementing the Edit/Update, Add
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

2. Cookbook:
Intro
to
Serlvets
and
JSP
• This cookbook in the Java EE Servlet /JSP tutorial
covers building CRUD Operations in a Model 2
architecture
• This is a continuation of Building a simple listing in
JSP using Java EE and Servlets (Part 1).
• This
is
part
2,
must
do
part
1
first
• Part
1
Slides
• Covers
working
with
Servlet
doGet/doPost
methods,
JSTL,
redirec8on
versus
forwarding
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

3. Redux:
About
tutorial
• Very
liNle
knowledge
of
HTML,
Java
and
JSP
is
assumed
• HTML
and
Java
not
covered
length,
but
pointers
in
the
right
direc8on
• Focus
is
Java
Servlets
and
JSP
(Java
Server
Pages)
• Use
whatever
IDE
you
would
like,
but
direc8ons
focus
on
Eclipse
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

4. Redux:
App
you
are
building
Sorting
Remove
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

5. Outline
• 1 Java EE Servlet Tutorial: Implementing a basic CRUD listing
• 2 Adding a link to the book listing to edit a book
• 2.1 Adding an edit book link to book-list.jsp listing
• 3 Adding a link to the book listing to add a book
• 3.1 Adding an add book link to book-list.jsp listing
• 4 Servlet doGet to load a Book form
• 4.1 BookEditorServlet.java doGet
• 4.2 BookEditorServlet.java doGet() delegate to book-form.jsp page
• 4.3 BookEditorServlet.java doGet() delegate to book-form.jsp page
• 5 Rendering the book form HTML
• 5.1 book-form.jsp Renders form to update or add a Book
• 5.2 book-form.jsp using JSTL c:choose to display update or add status
• 5.3 book-form.jsp using JSTL c:if to hidden id field for edit/update operation
• 6 Creating a doPost method to handle the form submission
• 6.1 BookEditorServlet.java doPost
• 7 Quick review of what we have so far
• 7.1 ./WebContent/WEB-INF/pages/book-form.jsp full listing
• 7.2 ./WebContent/WEB-INF/pages/book-list.jsp full listing
• 7.3 ./src/META-INF/beans.xml full listing
• 7.4 ./src/com/bookstore/Book.java
• 7.5 ./src/com/bookstore/BookRepositoryImpl.java full listing (testing only)
• 7.6 ./src/com/bookstore/BookRepository.java full listing
• 7.7 ./src/com/bookstore/web/BookEditorServlet.java
• 7.8 ./src/com/bookstore/web/BookListServlet.java
• 8 Technical debt
• 9 Cookbooks and Tutorials
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

6. Where
we
leX
off
in
last
example
• BookListServlet
uses
a
BookRepository
object
(DAO)
to
load
a
list
of
books
• BookListServlet
then
delegated
to
book-­‐list.jsp
to
render
the
book
lis8ng
with
JSTL
and
Unified
EL
• In
this
cookbook,
• add
a
link
to
the
book
lis9ng
for
edi9ng
a
book
• add
a
link
so
that
the
end
user
can
add
a
new
book
to
the
lis9ng
• Create
backend
Servlets
to
handle
new
links
on
book
lis9ng
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

7. Model
2
MVC
Model View Controller
•BookListingServlet
•Book •book-form.jsp •BookEditorServlet
•BookRepositoryImpl •book-list.jsp
•BookRepository
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

8. Add
a
new
link
to
book-­‐lis8ng.jsp
• Add
link
to
edit
opera8on
• Edit
opera8on
pulls
up
form
with
details
of
Book
8tle
that
is
clicked
• Uses
<a
href=””
• Uses
expression
pageContext.request.contextPath/book
to
address
new
Edit
Servlet
• Servlet
created
later,
id
parameter
implies
edit
opertaion
• EL
expression
pageContext.request.contextPath
refers
to
the
URI,
web
app
(war
file)
is
mapped
to
in
Servlet
container
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

9. Edit
Link
on
Title
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

10. What
gets
rendered
• The
following
links
with
URI
(/bookstore)
of
webapp
get
rendered
when
book-­‐
lis8ng.jsp
loads
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

11. Adding
a
“add
a
book”
link
to
book
lis8ng
• Now
that
links
are
going
to
URI
/book,
• You
need
a
Servlet
that
handles
links
• For
add
opera9on
and
edit
opera9on
• New
BookEditorServlet
will
handle
both
add
and
edit
book
func8ons
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

12. Add
Link
Above
Table
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

13. BookEditorServlet
• @WebServlet("/book")
maps
BookEditorServlet
to
the
URI
/
book
• Common
to
load
a
form
from
a
doGet
method,
and
to
handle
the
form
submission
via
doPost
• Follows
REST
and
HTTP
principles
GET
opera8ons
reads
data,
• later
POST
data
modifies
data
• doGet
method
uses
id
being
empty
or
not
to
• determine
if
this
is
a
load
"Add
Book
Form"
or
• load
"Update
Book
Form"
opera9on
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

14. BookEditorServlet
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

15. BookEditorServlet.doGet
loads
edit/add
form
Add Link
Edit Link
doGet is load form operation
book-form.jsp
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

16. Model
2
and
BookEditorServlet.doGet
• In
Model
2,
Servlets
(controllers/ac8ons)
prepares
model
data
for
the
view
• This
includes
date
formagng
Notice “book” is mapped into request scope
“book” will get used from book-form.jsp
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

17. Model
2
and
BookEditorServlet.doGet
(cont)
• To
render
the
HTML
form,
the
servlet
delegates
to
book-­‐form.jsp
book-form.jsp
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

18. book-­‐form.jsp
(1
of
3)
• book-­‐form.jsp
renders
form
to
edit
book
• If
book.id
present
then
edit
opera8on,
otherwise
add
opera8on
• JSTL
c:choose,
c:otherwise
to
display
correct
9tle
based
on
Update
(Edit)
or
Add
opera9on
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

19. book-­‐form.jsp
(2
of
3)
• Uses
Unified
EL
to
render
values
and
then
just
plain
HTML
for
form
fields
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

20. book-­‐form.jsp
(3
of
3)
• hidden
id
property
is
rendered
if
edit
(Update)
opera8on
• Cancel
buNon
takes
them
back
to
lis8ng
(/book/
is
lis8ng).
• Submit
buNon
POST
form
to
BookEditorServlet.doPost
(defined
next)
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

21. BookEditorServlet.doPost()
• if
id
request
parameter
is
null
then
BookEditorServlet.doPost
calls
bookRepo.addBook,
• otherwise
it
calls
bookRepo.updateBook
•
Then,
doPost
redirects
to
/book/
• redirect
means
an
extra
hit
to
the
server,
• basically
telling
browser
to
load
another
link
• Not
forward
like
before
because
of
bookmarking
• Remember
URL
/book/
(ending
in
slash)
represents
a
collec9on
of
books,
while
/book
(no
slash)
represents
a
single
book
• If
doPost
did
a
forward,
then
browser
would
show
wrong
link
for
lis9ng
• Use
sendRedirect
instead
of
a
forward
for
bookmarking
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

22. BookEditorServlet.doPost()
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

23. BookEditorServlet.doPost
book-form.jsp
BookListServlet
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

24. Review
of
CRUD
lis8ng
• Book
Form
• Servlet
that
loads
Book
(doGet)
form
• ./WebContent/WEB-­‐INF/pages/book-­‐form.jsp
and
handles
Book
form
submissions
(doPost).
• Book
Lis8ng
• ./WebContent/WEB-­‐INF/pages/book-­‐list.jsp
./src/com/bookstore/web/
BookEditorServlet.java
• Needed
for
Java
EE
dependency
injec8on
(CDI)
• ./src/META-­‐INF/beans.xml
• Servlet
that
looks
up
a
list
of
books
and
displays
the
lis8ng
• Domain/model
object
./src/com/bookstore/web/
• ./src/com/bookstore/Book.java
BookListServlet.java
• Repository
implementa8on
using
Java
collec8ons
(just
for
tes8ng)
• ./src/com/bookstore/BookRepositoryImpl.java
• Interface
to
Book
Repository
so
we
can
swap
it
out
with
JDBC,
JPA,
JCache
and
MongoDB
version
later
• ./src/com/bookstore/BookRepository.java
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server

25. Open%Source,%Reliable%and%Lightweight%
Java%EE%Applica;on%Server%
RESIN PRO Web Profile Health System Cloud Support

26. More
Info
• Caucho
Technology
|
Home
Page
• Resin
|
Applica8on
Server
• Resin
|
Java
EE
Web
Profile
Applica8on
Server
• Resin
-­‐
Cloud
Support
|
3G
-­‐
Java
Clustering
• Resin
|
Java
CDI
|
Dependency
Injec8on
/
IoC
• Resin
-­‐
Health
System
|
Java
Monitoring
and
Server
Monitoring
• Download
Resin
|
Applica8on
Server
• Watch
Resin
|
Applica8on
Server
Featured
Video
Caucho
Home
|
Contact
Us
|
Caucho
Blog
|
Wiki
|
Applica8on
Server