6
Building Clients that Use Web Services

This chapter describes the Oracle9iAS Web Services features that allow you to easily create and run a client application that uses Oracle9iAS Web Services.

This chapter contains the following topics:

Locating Web Services

When you want to use Web Services you need to develop a client application. There are two types of Web Services clients: static web service clients and dynamic web service clients. A static web service client knows where a Web Service is located without looking up the service in a UDDI registry. A dynamic web service client performs a lookup to find the Web Service's location in a UDDI registry before accessing the service. Chapter 8, "Discovering and Publishing Web Services" provides detailed information on looking up Web Services in a UDDI registry.

Using a static client Oracle9iAS Web Services provides several options for locating Oracle9iAS Web Services, including:

Using a known Web Service located at a known URL.
Using Oracle9iAS Web Services and a known service URL to obtain a client-side proxy Jar, or by other means obtaining a client-side proxy Jar for a Web Service. The client-side proxy Jar that Oracle9iAS Web Services generates includes the URL to locate the associated Web Service.
Using Oracle9iAS Web Services and a known service URL to obtain a WSDL file, or by other means obtaining a WSDL file that describes a Web Service. The WSDL files that Oracle9iAS Web Services generates includes the URL to locate the associated Web Service.

After you locate a Web Service or after you obtain either the WSDL or client-side proxy Jar, you can build a client-side application that uses the Web Service.

Getting WSDL Descriptions and Client-Side Proxy Jar for Web Services

Oracle9iAS Web Services supplies client-side programmers with the following files for deployed Web Services:

WSDL service descriptions
Client-side proxy Jar (class files)
Client-side proxy source

Getting WSDL Service Descriptions

To obtain the WSDL service description for a Web Service, use the Web Service URL and append a query string. The format for the URL to obtain the WSDL service description is as follows (see Table 6-1 for a description of the URL components):

http://host:port/context-root/service?WSDL

http://host:port/context-root/service?wsdl

This command returns a WSDL description in the form service.wsdl. The service.wsdl description contains the WSDL for the Web Service named service, located at the specified URL. Using the WSDL that you obtain, you can build a client application to access the Web Service.

Getting Client-Side Proxy Jar and Client-Side Proxy Source Jar

To obtain the client-side proxy Jar for a Web Service, use the Web Service URL and append a query string. The client-side proxy Jar file contains the proxy stubs class that supports building an application that communicates using SOAP to access the Web Service. The proxy class does the following:

Provides a static location for the Web Service (the service does not need to be looked up in a UDDI registry).
Provides proxy methods for each method exposed as part of the Web Service.
Performs all of the work to construct the SOAP request, including marshalling and unmarshalling parameters, and handling the response.

The format for the URL to obtain the client-side proxy Jar is as follows (see Table 6-1 for a description of the URL components):

http://host:port/context-root/service?PROXY_JAR

http://host:port/context-root/service?proxy_jar

This command returns the file service_proxy.jar. The service_proxy.jar is a Jar file that contains the client-side proxy classes that you can use to build a client-side application to access the Web Service.

To obtain the client-side proxy source Jar for a Web Service, use the Web Service URL and append a query string. The format for the URL to obtain the client-side proxy source Jar is as follows (see Table 6-1 for a description of the URL components):

http://host:port/context-root/service?PROXY_SOURCE

http://host:port/context-root/service?proxy_source

This command returns the file service_proxysrc.jar. The file
service_proxysrc.jar is a Jar file that contains the client-side proxy source files. This file represents the source code for the file service_proxy.jar associated with the service.

Getting Client-Side Proxy Jar and Client-Side Proxy Source with a Specified Package

When you obtain the client-side proxy Jar file or the client-side proxy source Jar, you have the option of including a request parameter that specifies a package name for the generated client-side proxy classes or source files. If the Web Service's client-side Java class is part of a particular package, then you should specify the package name to match the client-side application's package name.

The format for the URL to obtain the client-side proxy Jar and specify the package name is as follows (see Table 6-1 for a description of the URL components):

http://host:port/context-root/service?PROXY_JAR&packageName=mypackage

http://host:port/context-root/service?proxy_jar&packageName=mypackage

This command returns the file service_proxy.jar. The service_proxy.jar is a Jar file that contains the client-side proxy classes, using the specified package, mypackage for the Java package statement.

The format for the URL to obtain the client-side proxy source Jar and specify the package name is as follows (see Table 6-1 for a description of the URL components):

http://host:port/context-root/service?PROXY_SOURCE&packageName=mypackage

http://host:port/context-root/service?proxy_source&packageName=mypackage

This command returns the file service_proxysrc.jar. As for the proxy_jar, you have the option of specifying a request parameter with a supplied package name by include a packageName=name option. The serviceproxy_src.jar is a Jar file that contains the client-side source files for the client-side proxy that accesses the Web Service.

Table 6-1 URL for Accessing Client Side Proxy Stubs

URL Component	Description
context-root	The context-root is the value specified in the `<context-root>` tag for the web module associated with the Web Service. See the `META-INF/application.xml` in the Web Service's .ear file to determine this value.
host	This is the host of the Web Service's server running Oracle9iAS Web Services.
mypackage	This specifies the value that you want to use for the package name in the generated proxy Jar or proxy source.
port	This is the port of the Web Service's server running Oracle9iAS Web Services.
service	The service is the value specified in the `<url-pattern>` tag for the servlet associated with the Web Service. This is the service name. See the `WEB-INF/web.xml` in the Web Service's .war file to determine this value.

See Also:

Working with Client-Side Proxy Jar to Use Web Services

This section describes how to use the client-side proxy Jar when you are building the client-side application on a system with Oracle9iAS. When building client-side applications to access and use services under Oracle9iAS Web Services, the Oracle9iAS Web Services client-side proxy Jar class allows you to easily build the application.

The client side proxy Jar file that you get from a Web Service contains a Java class to serve as a proxy to the Web Service implementation residing on the Oracle9iAS Web Services server. The client-side proxy code constructs a SOAP request and marshalls and unmarshalls parameters for you. Using the proxy classes saves you the work of creating SOAP requests for accessing a Web Service or processing Web Service responses.

Example 6-1 shows a source code sample client-side proxy extracted from a Web Service. For each method available on the Web Service, there is a corresponding method in the proxy class. The example shows the method helloWorld(String) that serves as a proxy to the helloWorld(String) method in the associated Web Service implementation.

Example 6-2 shows client-side application code that uses the helloWorld() method from the supplied client-side proxy shown in Example 6-1.

Example 6-1 Sample Client-side Proxy Method for Web Services

/**
 * Web service proxy: StatefulExample
 *     generated by Oracle WSDL toolkit (Version: 1.0). */
public class StatefulExampleProxy {


   public java.lang.String helloWorld(java.lang.String param0) throws Exception
   {
   .
   .
   .
   }
.
.
.
}

Example 6-2 Sample Client-side Application Using a Proxy Class for Web Services

import oracle.j2ee.ws_example.proxy.*;

public class Client
{
  public static void main(String[] argv) throws Exception
  {
    StatefulExampleProxy proxy = new StatefulExampleProxy();
    System.out.println(proxy.helloWorld("Scott"));
    System.out.println(proxy.count());
    System.out.println(proxy.count());
    System.out.println(proxy.count());
  }
}

Using Web Services Security Features

When you run a client-side application that uses Oracle9iAS Web Services, you can access secure Web Services by setting properties in the client application. Table 6-2 shows the available properties that provide credentials and other security information for Web Services clients.

In a Web Services client application, you can set the security properties shown in Table 6-2 as system properties by using the -D flag at the Java command line, or you can also set security properties in the Java program by adding these properties to the system properties (use System.setProperties() to add properties). In addition, the client side stubs include the _setTranportProperties method that is a public method in the client proxy stubs. This method enables you to set the appropriate values for security properties by supplying a Properties argument.

Table 6-2 Web Services HTTP Transport Security Properties

Property	Description
`http.authType`	Specifies the HTTP authentication type. The case of the value specified is ignored. Valid values: `basic`, `digest` The value basic specifies HTTP basic authentication. Specifying any value other than `basic` or `digest` is the same as not setting the property.
`http.password`	Specifies the HTTP authentication password.
`http.proxyAuthType`	Specifies the proxy authentication type. The case of the value specified is ignored. Valid values: `basic`, `digest` Specifying any value other than `basic` or `digest` is the same as not setting the property.
`http.proxyHost`	Specifies the hostname or IP address of the proxy host.
`http.proxyPassword`	Specifies the HTTP proxy authentication password.
`http.proxyPort`	Specifies the proxy port. The specified value must be an integer. This property is only used when `http.proxyHos`t is defined; otherwise this value is ignored. Default value: `80`
`http.proxyRealm`	Specifies the realm for which the proxy authentication username/password is specified.
`http.proxyUsername`	Specifies the HTTP proxy authentication username.
`http.realm`	Specifies the realm for which the HTTP authentication username/password is specified.
`http.username`	Specifies the HTTP authentication username.
`java.protocol. handler.pkgs`	Specifies a list of package prefixes for `java.net.URLStreamHandlerFactory` The prefixes should be separated by "\|" vertical bar characters. This value should contain: `HTTPClient`This value is required by the Java protocol handler framework; it is not defined by Oracle9i Application Server. This property must be set when using HTTPS. If this property is not set using HTTPS, a `java.net.MalformedURLException` is thrown. Note: This property must be set as a system property. For example, set this property as shown in either of the following: `java.protocol.handler.pkgs=HTTPClient` `java.protocol.handler.pkgs=sun.net.www.protocol\| HTTPClient`
`oracle.soap. transport. allowUserInteraction`	Specifies the allows user interaction parameter. The case of the value specified is ignored. When this property is set to `true` and either of the following are true, the user is prompted for a username and password: If any of properties `http.authType,` `http.username`, or `http.password` is not set, and a `401` HTTP status is returned by the HTTP server. If either of properties `http.proxyAuthType`, `http.proxyUsername`, or `http.proxyPassword` is not set and a `407` HTTP response is returned by the HTTP proxy. Valid values: `true`, `false` Specifying any value other than `true` is considered as `false`.
`oracle.ssl.ciphers`	Specifies a list of`:` separated cipher suites that are enabled. Default value: The list of all cipher suites supported with Oracle SSL.
`oracle. wallet.location`	Specifies the location of an exported Oracle wallet or exported trustpoints. Note: The value used is not a URL but a file location, for example: `/etc/ORACLE/Wallets/system1/exported_wallet` (on UNIX) `d:\oracle\system1\exported_wallet` (on Windows) This property must be set when HTTPS is used with SSL authentication, server or mutual, as the transport.
`oracle.wallet. password`	Specifies the password of an exported wallet. Setting this property is required when HTTPS is used with client, mutual authentication as the transport.

Working with WSDL and JDeveloper to Use Web Services

The Web Services WSDL allows you to manually, or using Oracle9i JDeveloper or another IDE, build client applications that use Web Services.

The Oracle9i JDeveloper IDE supports Oracle9iAS Web Services with WSDL features and provides unparalleled productivity for building end-to-end J2EE and integrated Web Services applications.

JDeveloper supports Oracle9iAS Web Services with the following features:

Allows developers to create Java stubs from Web Services WSDL descriptions to programmatically use existing Web Services.
Allows developers to create a new Web Service from Java or EJB classes, automatically producing the required deployment descriptor, web.xml, and WSDL file for you.
Provides schema-driven WSDL file editing.
Offers significant J2EE deployment support for Web Services J2EE .ear files, with automatic deployment to OC4J.

Non-Oracle Web Services IDEs or client development tools can use the supplied WSDL file to generate Web Services requests for services running under Oracle9iAS Web Services. Currently, many IDEs have the capability to create SOAP requests, given a WSDL description for the service.

6 Building Clients that Use Web Services