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Overview
Web services are discrete reusable software components that can be incorporated into applications. They build upon existing XML and HTTP protocols and use the following standards:
WSDL (Web Services Description Language): an XML-based language for defining web services
SOAP (Simple Object Access Protocol): an XML-based protocol for accessing services on the Web by using XML syntax to send commands over HTTP
UDDI (Universal Description, Discovery, and Integration): a universal catalog of web services that enables software to discover and integrate with services on the Web
JDeveloper provides many features to help you to create and
deploy web services and to find existing web services to use in your applications.
This tutorial shows you how to create and deploy a web service based on an existing
PL/SQL package. You deploy the resulting web service to OC4J and then test it
to ensure correct functionality.
Have access to or have installed Oracle JDeveloper
(10.1.3.1.0). You can download it from Oracle
Technology Network.
2.
Have started JDeveloper by double-clicking <jdev_install>\jdeveloper.exe.
If you receive a message asking if you want to migrate
from a previous version, click No.
3.
Have access to or have installed the Oracle Sample
Schemas, included with Oracle Database 10g.
The tutorial uses the HR schema. Specifically, the
pages work with the EMPLOYEES table. Instructions for installing the
HR schema are available online at:
Have copied the following file
to the temp directory on
your local machine.
5.
Have started Oracle Application Server Containers
for J2EE (OC4J) by double-clicking <jdev_install>\jdev\bin\start_oc4j.bat.
If prompted for a password, enter welcome1.
Nothing displays as you enter the password. You will have to reenter
it on the next line to confirm. If you are not asked for a password,
for later steps you will need to know what password was set when OC4J
was initially started.
Watch the resulting command window and wait until you see the message
'Oracle Containers for J2EE 10g (10.1.3.1.0) initialized'. Then you
can minimize the window, but do not close it.
6.
Have created a connection in JDeveloper to OC4J:
Click the Connections tab (If the Connections tab
is not visible, choose View > Connection
Navigator from the menu).
Right-click the Application Server node and select
New Application Server Connection from the context
menu.
If the Welcome page of the Create Application Server Connection
wizard displays, click Next.
On the Type page of the wizard, enter the Connection Name of oc4jconn
and click Next.
On the Authentication page of the wizard, enter a Password of welcome1
(or whatever password was used when OC4J was initially started) and
select Deploy Password, then click Next.
On the Connection page of the wizard, click Next.
On the Test page of the wizard, click Test Connection.
After testing, the Status message should display Success!. (If it
displays error messages, click Back and correct the connection information
that you have entered. )
Java Database Connectivity (JDBC) is a standard application
programming interface (API) that is used for connecting a Java application to
relational databases. JDeveloper's Connection Navigator maintains connection
information for your application.
To create a JDBC connection to the HR schema, perform
the following steps:
1.
Click the Connections tab on the
Application Navigator. If the Connections tab is not showing, choose
View | Connection Navigator from the JDeveloper main menu.
2.
Right-click the Database node and choose
New Database Connection from the context menu.
3.
In the Create Database Connection Wizard, review
the information on the Welcome page and then click
Next.
4.
In the Connection Name field, enter hrconn.
Click Next to continue.
5.
On the Authentication page: enter hr
in the Username field and hr
in the Password field. Check Deploy Password.
Click Next to continue.
6.
On the Connections page, the default values for
the connection should be the following:
Driver: Thin
Host name: localhost
JDBC Port: 1521
SID: ORCL
Leave the fields set to these default values.
Click Next to continue.
7.
Click Test Connection.
If the database is available and the connection details are correct,
you see the word Success! displayed in the
Status window.
If an error occurs, verify the connection settings, click Back
to make any necessary changes, and then retest the connection.
If the connection is successful, click Finish to complete the
connection.
You have just created a connection to the database.
In the next topic you install the PL/SQL package in this database.
Installing
the PL/SQL Package in the Database
You should already have copied the EMP_PACKAGE.sql
file to your temp directory, as suggested in the Prerequisites. If you have
not already done this, you can find the file here.
To install the PL/SQL package in the HR schema, perform
the following steps:
1.
In the Connections Navigator expand the Database
node if it is not already expanded, and right-click the hrconn
connection that you just created. Choose SQL*Plus from
the context menu.
2.
Type hr as the password when prompted.
Then press Enter.
3.
Run the EMP_PACKAGE.sql
file that you downloaded to your temp
directory.
The package is created in the database.
4.
In the Connections Navigator, expand the
hrconn node, and the HR schema node. Scroll
down to the Packages node and expand it. You should
see the package that you just installed.
To create the web service from the PL/SQL package, perform
the following steps:
1.
In the Connections Navigator, expand the EMP_FETCHER
package node and right click EMP_FETCHER. This is the
header part of the package. Choose Open from the context
menu.
2.
The Code Editor opens and displays the code for the package header.
The code shows that the PL/SQL package gets an input value for an employee
number and returns the record for that employee.
3.
In the Connections Navigator, right click the EMP_FETCHER
> EMP_FETCHER node and select the Publish as Web
Service option.
4.
In the Select J2EE Web Service Version, select J2EE 1.4
(JAX-RPC) and click OK.
5.
On the Welcome page of the Create PL/SQL J2EE Web Service page,
click Next.
6.
In Step 1of the wizard, ensure the GetEmployee.jpr
project is selected in the Target Project list, then click Next.
Notice that JDeveloper defaults the name to the project you are currently
in.
7.
In Step 2 set the Web Service Name to EmpWebService
and ensure that the SOAP 1.1.Binding option is selected.
Click Next.
8.
In Step 3 click Next to accept the default options.
9.
In Step 4 check the GET_EMP function that you want
to publish as a web service. Click Next.
10.
In Step 5 click Next to accept the default type
mappings.
11.
In Step 6 click Next since you don't require any
user defined type mappings for this web service.
12.
In Step 7, click Next to accept the defaults and
then Finish.
13.
The web service, EmpWebService is created, and
the EmpWebService .wsdl
file is opened in the Design Editor.
14.
Click the EmpWebService node in the Applications
Navigator and open the Structure pane to display the elements generated
for this Web Service.
The EmpWebServiceBase.java
class has all the database connection parameters in it.The Web Services
generator uses JPublisher to generate the Web Service.
15.
Return to the WSDL in the Design Editor and expand some of the
nodes to see details of the package exposed as a web service.
In the Bindings section of the diagram experiment with clicking on
the input and output entries.
The WebServices engine knows how to call the package and method from
this wsdl description.
Double click the EmpWebService tab on top of the WSDL
Design editor to reduce the design pane to its previous size.
16.
Click the Source tab at the bottom of the WSDL, and then scroll
down to the soap:address
location tag. It should look something like http://<your
machine name>/PL_SQL_WS-GetEmployee-context-root/EmpWebServiceSoapHttpPort.
Copy this URL to the clipboard; you use it in the next topic.
At this point, the wsdl has been generated. It doesn't matter if
the underlying implementation is a PL/SQL package or a Java Class. The
beauty of web services is that you are abstracted from the underlying
implementation of the service.
To deploy and test the web service that you have created, perform the following steps:
1.
In the Applications Navigator, expand the Resources
node. Right-click WebServices.deploy, and select
Deploy to > oc4jconn from the context menu.
(Note: This assumes that you have started OC4J and
have created a connection to it as described in Prerequisites.)
In the Configure Application dialog, click OK.
The log window should show successful deployment.
2.
Open a browser and paste the URL you copied from the WSDL file
above, which is the EmpWebService endpoint page generated by OC4J.
The endpoint page for the EmpWebService displays. Note the getEmp
operation.
3.
The page displays an area where you can specify parameters for the
operation. In the box provided enter the number 100,
to return the record of the employee with the Id 100. Click
Invoke.
4.
After you invoke the web service, the window displays the SOAP envelope
containing the test result, which is the record of Employee 100, King,
who is the President of the organization.
5.
Retest the getEmp method with a different value:
Click Back to return to the getEmp page.
In the parameter value field enter the number 120,
to return a different employee.
Click Invoke.
The Test Result page contains the result, which is the record of
the employee with the Id 120,and the last name, Weiss
Summary
In this tutorial you used JDeveloper to create a web service
from a PL/SQL package. You then deployed the web service to OC4J and tested
it in a browser.
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