Pracownia 3-4 – Rozproszone Systemy Internetowe

 

 

 

 

1. Utworzyć prostą usługę internetową Apache Axis2 w środowisku Netbeans oraz aplikację kliencką - HelloService

2. Zaimplementować aplikację w architekturze usługa webowa – klient prezentującą zawartość dowolnej tabeli

3. Zaimplementować aplikację w architekturze usługa webowa – modyfikującą zawartość dowolnej tabeli

Przykładowy kod odczytu /modyfikacji tabel na stronie PAWWW

 

4. Utworzyć prostą usługę internetową Apache Axis2 bezpośrednio w środowisku serwera webowego

 

 

 

 

 

 

 

Zadanie 1 -3

 

Creating Apache Axis2 Web Services on NetBeans IDE

This tutorial shows you how to create and deploy an Apache Axis2 web service from a Java class. You also learn how to set up the Tomcat and GlassFish servers bundled with NetBeans IDE to deploy Axis2 web services. The tutorial also shows how to configure the Axis2 options in the IDE so that the IDE deploys Axis2 web services correctly.

Apache Axis is an implementation of the SOAP (Simple Object-Access Protocol) submission to the W3C. Apache Axis2 is a more efficient, more modular and more XML-oriented version of Axis. Axis2 not only supports SOAP 1.1 and SOAP 1.2, but it also has integrated support for RESTful web services. The same business logic implementation can offer both a WS-* style interface as well as a REST/POX style interface simultaneously. For more information about Axis2, please see the Apache.org website.

Axis2 web services are interoperable with Metro. You can create a JAX-WS client for an Axis2 web service, although some more complicated Axis2 WSDL operations may not be supported.

Contents

Content on this page applies to NetBeans IDE 6.5 and 6.7

·                                 Setting Up Axis2 and NetBeans IDE

o                                                        Downloading the Apache Axis2 WAR file

o                                                        Installing the Axis2 Support Plugin

o                                                        Setting Up Axis2 Options for Tomcat

o                                                        Setting Up Axis2 Options for GlassFish

·                                 Creating an Axis2 Web Service

o                                                        Deploying and Testing an Axis2 Web Service

o                                                        Changing the Web Service's Operations

·                                 Troubleshooting

·                                 More Exercises

To follow this tutorial, you need the following software and resources.

Software or Resource

Version Required

NetBeans IDE

Java download bundle

Java Development Kit (JDK)

version 6 or
version 5

Apache Axis 2

version 1.3 or later, WAR distribution

Java EE-compliant web or application server

Tomcat web server 6.0 and/or
GlassFish application server v2 or v3

Both Tomcat and GlassFish can be installed with the Java Web distribution of NetBeans IDE. Alternatively, you can visit the GlassFish downloads page or the Apache Tomcat downloads page.

In this section you learn how to download an Axis2 WAR file, embed it in either an Apache Tomcat or GlassFish server, and configure NetBeans IDE to upload AAR files to the server.

Downloading the Apache Axis2 WAR file

Apache Axis2 can be downloaded here. Download the WAR (Web Archive) distribution, so you do not have to build the WAR file yourself. The download is in the form of an archive file. Later you unpack the archive to your server.

Installing the Axis2 Support Plugin

This tutorial requires the Axis2 Support plugin for the NetBeans IDE. In the IDE, go to the Plugin Manager, under the Tools menu, and check whether Axis2 Support Plugin is installed, under the Installed tab. If it is installed, check whether an update is available in the Updates tab. If the Axis2 support is not installed, install it from the Available Plugins tab, as shown below.

Screenshot of Plugin Manager showing the Axis2 Support plugin

Setting Up Axis2 Options for Tomcat

Axis services run faster on Tomcat than on GlassFish, but the setup is slightly more complicated. You can easily deploy the same service to both Tomcat and GlassFish by first deploying to one server, then changing the Axis2 options and finally deploying to the other server.

If you want to deploy to GlassFish instead of Tomcat, go to Setting Up Axis2 Options for GlassFish.

Setting Up Axis2 Options for GlassFish

You can deploy Axis2 web services to the GlassFish application server. You can easily deploy the same service to both Tomcat and GlassFish by first deploying to one server, then changing the Axis2 options and finally deploying to the other server.

If you want to deploy to Tomcat instead of GlassFish, go to Setting Up Axis2 Options for Tomcat.

To set up Axis2 options for Glassfish:

1.       Unpack the downloaded archive file containing axis2.war to GLASSFISH_HOME/domains/DOMAIN_NAME/autodeploy. To find GLASSFISH_HOME and the name of your domain, start the IDE and open the Services tab. Expand the Servers node. Right-click the GlassFish V2 or V3 node and select Properties from the context menu. The Domains folder location and the name of the domain are visible in the Connection tab. For example, from the following image, you know to copy axis2.war to G:\glassfish-v2ur2\domains\domain1\autodeploy.
GlassFish properties page showing path to GlassFish domains directory and domain name

2.       Start the IDE. From the top menu bar, choose Tools -> Options. The Options dialog opens.

3.       Click the Axis2 icon. The Axis2 deployment options page opens.
Axis2 options page set up for GlassFish

4.       Set the target location for Axis2 AAR files to the axis2.war file you unpacked into the GlassFish autodeploy directory.

By placing axis2.war into autodeploy, you enable GlassFish to automatically redeploy axis2.war every time you alter the file. On GlassFish v3 Prelude, however, you cannot redeploy the WAR file while the server is running.

5.       Make sure the Axis2 URL field contains the correct port number for your GlassFish server. To check the port number, start GlassFish (from the Services tab or from Tools -> Servers) and see what 80xx port HTTP 1.1 uses. The default port number is 8080. In the following image, the correct port number is 8081 (because another server already uses 8080).
GlassFish server output showing HTTP port number 8081

Note: If you are using Windows Vista, have GlassFish installed to Program Files, and have User Access Control enabled, you will not be able to make changes to the axis2.war file from the IDE. Either install GlassFish to a different location or disable UAC.

In this section, you use NetBeans IDE to create, deploy, test, and modify an Axis2 web service.

Creating an Axis2 Web Service

With NetBeans IDE, you can create an Axis2 web service from a Java class. You can only do this from a Java application or Java library project. In this tutorial, you create a Java library project (because you do not need a main method), create an Axis2 web service in that project (creating the Java class at the same time) and deploy the Axis2 web service to a server.

You can only create an Axis2 web service from a Java or Java Library project. This is because the axis.aar file (the deployable archive into which web services and Axis configuration files are packed) is neither a WAR nor an EAR and cannot be deployed normally as a web (EAR) application.

To create an Axis2 web service:

1.       Click the New Project icon or File -> New Project. The New Project wizard opens. From the Java category, select a Java class library project. Click Next.

2.       Name the project AxisHello. Check that you are using the project folder name and location that you want. It is up to you whether to share the project. Click Finish, and the IDE creates the project.

3.       Right-click the project node. The context menu opens. In the context menu, choose New -> Other. The New File wizard opens. From the Web Services category, choose Axis2 Service from Java and click Next.
Choosing to create an Axis2 Service from Java in the New File wizard

4.       The Service Type Selection page of the New File wizard is now open. You do not have any Java classes in the project, so select "Create an Empty Web Service." If you had already coded a Java class, you would have selected Create a Web Service from an Existing Java Class. If you wanted to edit the WSDL of the web service, for example to add or change namespaces, you would select Generate a WSDL from Java Source Code. Editing WSDL is outside the scope of this tutorial, so leave this unselected. The wizard should look like the following image.
Service Type Selection page set up to Create an Empty Web Service

5.       Click Next. The Name and Location page opens. Name the Java class HelloAxisWorld. Name the package axishello. Leave Generate Sample Method selected. This generates a method in the Java class that returns "Hello, World."

6.       Click Finish. The IDE generates a HelloAxisWorld.java class in the axishello source package and a HelloAxisWorld Axis2 web service that mirrors this Java class. You can see that both the Java class and the Axis2 web service have a hello:String operation, shown in the Navigator tab and as a node of the Axis2 web service, respectively.
Navigator and Project tabs showing identical Axis2 web service and Java class operations

Deploying and Testing an Axis2 Web Service

Once you have created an Axis2 web service, you need to deploy it to a server. Actually, deployment to a server involves two steps:

1.       Copying the Axis2 web service to the axis2.war file used by the server. This step can be taken with the server offline.

2.       Redeploying the updated axis2.war file to the server.

If you are deploying to Tomcat with the Use Tomcat Manager for Deployment option enabled (see Setting Up Axis2 Options for Tomcat), or you are deploying to GlassFish and axis2.war is in the GLASSFISH_DOMAIN/autodeploy folder (see Setting Up Axis2 Options for GlassFish), the updated axis2.war is automatically redeployed to the server. Otherwise, you have to redeploy axis2.war manually, using application server tools. In this tutorial we assume you have set up the Axis2 options so redeployment is automatic.

To deploy an Axis2 web service to the server:

1.       Right-click the web service's node. The context menu opens. Select Deploy to Server. The IDE compiles an Axis2 AAR file and copies it to the axis2.war file used by the application server.

2.       If you have enabled automatic deployment, the web service is deployed to the server. If the server is not running, start it and the web service is automatically deployed.

3.       To test the service, expand the web service node to reveal the operations. Right-click the hello:String node and select Test Operation in Browser.
Operation subnode context menu showing the option to Test Operation in Browser

4.       Your browser opens with a test value of your variables. The test value is appended to the URL.
Browser window showing operation test results and test values appended to URL

5.       Change the variable value in the URL and press Enter. The test result changes as well.
Browser window showing operation test results and altered values

Changing the Web Service's Operations

To change the web service operations, edit the Java file in the project. The operations in the web service change simultaneously. Add a simple add method to HelloAxisWorld.java, as below.

public class HelloAxisWorld {
 
    /** Sample method
    */
    public String hello(String name) {
        return "Hello "+name;
    }
    public int add(int x, int y) {
            return x+y;
    }
 }

Save the Java file, and the operation appears as a subnode of the web service.
Projects tab showing new operation subnode to web service

Redeploy the web service and test it as described in Deploying and Testing an Axis2 Web Service.

Here are some difficulties you may experience and their solutions:

·                                 The service is not automatically deployed on Tomcat. If autodeploy does not appear to work on Tomcat, open TOMCAT_HOME/conf/server.xml and check that the autoDeploy attribute is set to "true" in the Host element:

·                                        <Host name="localhost"  appBase="webapps"
·                                              unpackWARs="true" autoDeploy="true"
·                                              xmlValidation="false" xmlNamespaceAware="false">
·                                         
        

·                                 When you change the operations in the service and try to redeploy the service on Tomcat, it fails with the following message in the Tomcat server output window: INFO: validateJarFile(C:\...\apache-tomcat-6.0.16_base\webapps\axis2\WEB-INF\lib\servlet-api-2.3.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class

In this case, stop the server, delete the CATALINA_BASE/webapps/axis2 folder, and restart the server. This regenerates a new axis2 folder.

·                                 Using GlassFish on Windows Vista, you cannot unpack, modify and overwrite the WAR file. You need to either reinstall GlassFish in a different location than C:/Program Files, or disable User Access Control.

·                                 Using GlassFish v3 b20 Prelude, with the server running, you cannot unpack, modify and overwrite the WAR file. You cannot overwrite a JAR file used by a running GlassFish v3 b20 Prelude server. Stop the server and deploy the service, then restart the server.

·                                 The name=XYZ parameter is not recognized; Axis 2 always receives null parameters even if the SOAP message is correct. Some users experience this issue some of the time. If it persists, you have to edit the WSDL manually and replace unnecessary complex types with simple types. See this Stackoverflow thread.

More Exercises

Here are a few more ideas for you to explore:

·                                 Create a JAX-WS client for the Axis2 web service. You need the web service's WSDL URL. To get the WSDL URL, right-click the web service node and select Properties. The WSDL file URL is on the Properties page. See Getting Started with JAX-WS Web Services and Developing JAX-WS Web Service Clients for more information about JAX-WS web services.

·                                 Try deploying the web service to the other application server. You have to change the Axis2 options--see Setting Up Axis2 Options for Tomcat or Setting Up Axis2 Options for GlassFish.

·                                 Expose an existing Java class as an Axis2 web service. The Java class has to be in a Java Application or Java Class Library project.

 

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See Also

For more information about using NetBeans IDE to create and consume web services, see the following resources:

·                                 Developing JAX-WS Web Service Clients

·                                 Getting Started with JAX-WS Web Services

·                                 Web Services Learning Trail

 

 

 

 

 

Zadanie 4  - rozdział 5 oraz 6

 

 

 

 

 

 

Axis installation instructions

Table of Contents

Introduction

This document describes how to install Apache Axis. It assumes you already know how to write and run Java code and are not afraid of XML. You should also have an application server or servlet engine and be familiar with operating and deploying to it. If you need an application server, we recommend Jakarta Tomcat. [If you are installing Tomcat, get the latest 4.1.x version, and the full distribution, not the LE version for Java 1.4, as that omits the Xerces XML parser]. Other servlet engines are supported, provided they implement version 2.2 or greater of the servlet API. Note also that Axis client and server requires Java 1.3 or later.

For more details on using Axis, please see the user guide.

Things you have to know

A lot of problems with Axis are encountered by people who are new to Java, server-side Java and SOAP. While you can learn about SOAP as you go along, writing Axis clients and servers is not the right time to be learning foundational Java concepts, such as what an array is, or basic application server concepts such as how servlets work, and the basics of the HTTP protocol.

Things you need to know before writing a Web Service:

1.        Core Java datatypes, classes and programming concepts.

2.        What threads are, race conditions, thread safety and sychronization.

3.        What a classloader is, what hierarchical classloaders are, and the common causes of a "ClassNotFoundException".

4.        How to diagnose trouble from exception traces, what a NullPointerException (NPE) and other common exceptions are, and how to fix them.

5.        What a web application is; what a servlet is, where classes, libraries and data go in a web application.

6.        How to start your application server and deploy a web application on it.

7.        What a network is, the core concepts of the IP protocol suite and the sockets API. Specifically, what is TCP/IP.

8.        What HTTP is. The core protocol and error codes, HTTP headers and perhaps the details of basic authentication.

9.        What XML is. Not necessarily how to parse it or anything, just what constitutes well-formed and valid XML.

Axis and SOAP depends on all these details. If you don't know them, Axis (or anyone else's Web Service middleware) is a dangerous place to learn. Sooner or later you will be forced to discover these details, and there are easier places to learn than Axis.

If you are completely new to Java, we recommend you start off with things like the Java Tutorials on Sun's web site, and perhaps a classic book like Thinking in Java, until you have enough of a foundation to be able to work with Axis. It is also useful to have written a simple web application, as this will give you some knowledge of how HTTP works, and how Java application servers integrate with HTTP. You may find the course notes from Mastering the World Wide Web useful in this regard, even though Axis is only introduced in lecture 28.

Be aware that there is a lot more needed to be learned in order to use Axis and SOAP effectively than the listing above. The other big area is "how to write internet scale distributed applications". Nobody knows how to do that properly yet, so that you have to learn this by doing.

Step 0: Concepts

Apache Axis is an Open Source SOAP server and client. SOAP is a mechanism for inter-application communication between systems written in arbitrary languages, across the Internet. SOAP usually exchanges messages over HTTP: the client POSTs a SOAP request, and receives either an HTTP success code and a SOAP response or an HTTP error code. Open Source means that you get the source, but that there is no formal support organisation to help you when things go wrong.

SOAP messages are XML messages. These messages exchange structured information between SOAP systems. Messages consist of one or more SOAP elements inside an envelope, Headers and the SOAP Body. SOAP has two syntaxes for describing the data in these elements, Section 5, which is a clear descendant of the XML RPC system, and XML Schema, which is the newer (and usually better) system. Axis handles the magic of converting Java objects to SOAP data when it sends it over the wire or receives results. SOAP Faults are sent by the server when something goes wrong; Axis converts these to Java exceptions.

SOAP is intended to link disparate systems. It is not a mechanism to tightly bind Java programs written by the same team together. It can bind Java programs together, but not as tightly as RMI or Corba. If you try sending many Java objects that RMI would happily serialize, you will be disappointed at how badly Axis fails. This is by design: if Axis copied RMI and serialized Java objects to byte streams, you would be stuck to a particular version of Java everywhere.

Axis implements the JAX-RPC API, one of the standard ways to program Java services. If you look at the specification and tutorials on Sun's web site, you will understand the API. If you code to the API, your programs will work with other implementations of the API, such as those by Sun and BEA. Axis also provides extension features that in many ways extends the JAX-RPC API. You can use these to write better programs, but these will only work with the Axis implementation. But since Axis is free and you get the source, that should not matter.

Axis is compiled in the JAR file axis.jar; it implements the JAX-RPC API declared in the JAR files jaxrpc.jar and saaj.jar. It needs various helper libraries, for logging, WSDL processing and introspection. All these files can be packaged into a web application, axis.war, that can be dropped into a servlet container. Axis ships with some sample SOAP services. You can add your own by adding new compiled classes to the Axis webapp and registering them.

Before you can do that, you have to install it and get it working.

Step 1: Preparing the webapp

Here we assume that you have a web server up and running on the localhost at port 8080. If your server is on a different port, replace references to 8080 to your own port number.

In your Application Server installation, you should find a directory into which web applications ("webapps") are to be placed. Into this directory copy the webapps/axis directory from the xml-axis distribution. You can actually name this directory anything you want, just be aware that the name you choose will form the basis for the URL by which clients will access your service. The rest of this document assumes that the default webapp name, "axis" has been used; rename these references if appropriate.

Step 2: Setting up the libraries

In the Axis directory, you will find a WEB-INF sub-directory. This directory contains some basic configuration information, but can also be used to contain the dependencies and web services you wish to deploy.

Axis needs to be able to find an XML parser. If your application server or Java runtime does not make one visible to web applications, you need to download and add it. Java 1.4 includes the Crimson parser, so you can omit this stage, though the Axis team prefer Xerces.

To add an XML parser, acquire the JAXP 1.1 XML compliant parser of your choice. We recommend Xerces jars from the xml-xerces distribution, though others mostly work. Unless your JRE or app server has its own specific requirements, you can add the parser's libraries to axis/WEB-INF/lib.  The examples in this guide use Xerces.  This guide adds xml-apis.jar and xercesImpl.jar to the AXISCLASSPATH so that Axis can find the parser (see below).

If you get ClassNotFound errors relating to Xerces or DOM then you do not have an XML parser installed, or your CLASSPATH (or AXISCLASSPATH) variables are not correctly configured.

Tomcat 4.x and Java 1.4

Java 1.4 changed the rules as to how packages beginning in java.* and javax.* get loaded. Specifically, they only get loaded from endorsed directories. jaxrpc.jar and saaj.jar contain javax packages, so they may not get picked up. If happyaxis.jsp (see below) cannot find the relevant packages, copy them from axis/WEB-INF/lib to CATALINA_HOME/common/lib and restart Tomcat.

WebLogic 8.1

WebLogic 8.1 ships with webservices.jar that conflicts with Axis' saaj.jar and prevents Axis 1.2 from working right out of the box. This conflict exists because WebLogic uses an older definition of javax.xml.soap.* package from Java Web Services Developer Pack Version 1.0, whereas Axis uses a newer revision from J2EE 1.4.

However, there are two alternative configuration changes that enable Axis based web services to run on Weblogic 8.1.

  • In a webapp containing Axis, set <prefer-web-inf-classes> element in WEB-INF/weblogic.xml to true. An example of weblogic.xml is shown below:

·                <weblogic-web-app>

·                  <container-descriptor>

·                    <prefer-web-inf-classes>true</prefer-web-inf-classes>

·                  </container-descriptor>

</weblogic-web-app>

If set to true, the <prefer-web-inf-classes> element will force WebLogic's classloader to load classes located in the WEB-INF directory of a web application in preference to application or system classes. This is a recommended approach since it only impacts a single web module.

  • In a script used to start WebLogic server, modify CLASSPATH property by placing Axis's saaj.jar library in front of WebLogic's webservices.jar.

NOTE: This approach impacts all applications deployed on a particular WebLogic instance and may prevent them from using WebLogic's webservices.

For more information on how WebLogic's class loader works, see WebLogic Server Application Classloading.

Step 3: starting the web server

This varies on a product-by-product basis. In many cases it is as simple as double clicking on a startup icon or running a command from the command line.

Step 4: Validate the Installation

After installing the web application and dependencies, you should make sure that the server is running the web application.

Look for the start page

Navigate to the start page of the webapp, usually http://127.0.0.1:8080/axis/, though of course the port may differ.

You should now see an Apache-Axis start page. If you do not, then the webapp is not actually installed, or the appserver is not running.

Validate Axis with happyaxis

Follow the link Validate the local installation's configuration
This will bring you to happyaxis.jsp a test page that verifies that needed and optional libraries are present. The URL for this will be something like
http://localhost:8080/axis/happyaxis.jsp

If any of the needed libraries are missing, Axis will not work.
You must not proceed until all needed libraries can be found, and this validation page is happy.
Optional components are optional; install them as your need arises. If you see nothing but an internal server error and an exception trace, then you probably have multiple XML parsers on the CLASSPATH (or AXISCLASSPATH), and this is causing version confusion. Eliminate the extra parsers, restart the app server and try again.

Look for some services

From the start page, select View the list of deployed Web services. This will list all registered Web Services, unless the servlet is configured not to do so. On this page, you should be able to click on (wsdl) for each deployed Web service to make sure that your web service is up and running.

Note that the 'instant' JWS Web Services that Axis supports are not listed in this listing here. The install guide covers this topic in detail.

Test a SOAP Endpoint

Now it's time to test a service. Although SOAP 1.1 uses HTTP POST to submit an XML request to the endpoint, Axis also supports a crude HTTP GET access mechanism, which is useful for testing. First let's retrieve the version of Axis from the version endpoint, calling the getVersion method:

http://localhost:8080/axis/services/Version?method=getVersion

This should return something like:

<?xml version="1.0" encoding="UTF-8" ?>

<soapenv:Envelope

 xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"

 xmlns:xsd="http://www.w3.org/2001/XMLSchema"

 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <soapenv:Body>

    <getVersionResponse

     soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">

      <getVersionReturn

       xsi:type="xsd:string">

         Apache Axis version: 1.1 Built on Apr 04, 2003 (01:30:37 PST)

      </getVersionReturn>

    </getVersionResponse>

  </soapenv:Body>

</soapenv:Envelope>

The Axis version and build date may of course be different.

Test a JWS Endpoint

Now let's test a JWS web service. Axis' JWS Web Services are java files you save into the Axis webapp anywhere but the WEB-INF tree, giving them the .jws extension. When someone requests the .jws file by giving its URL, it is compiled and executed. The user guide covers JWS pages in detail.

To test the JWS service, we make a request against a built-in example, EchoHeaders.jws (look for this in the axis/ directory).

Point your browser at http://localhost:8080/axis/EchoHeaders.jws?method=list.

This should return an XML listing of your application headers, such as

<?xml version="1.0" encoding="UTF-8" ?>

<soapenv:Envelope

 xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"

 xmlns:xsd="http://www.w3.org/2001/XMLSchema"

 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <soapenv:Body>

    <listResponse

     soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">

      <listReturn xsi:type="soapenc:Array"

       soapenc:arrayType="xsd:string[6]"

       xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/">

        <item>accept:image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*</item>

        <item>accept-language:en-us</item>

        <item>accept-encoding:gzip, deflate</item>

        <item>user-agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)</item>

        <item>host:localhost:8080</item>

        <item>connection:Keep-Alive</item>

      </listReturn>

    </listResponse>

  </soapenv:Body>

</soapenv:Envelope>

Again, the exact return values will be different, and you may need to change URLs to correct any host, port and webapp specifics.

Step 5: Installing new Web Services

So far you have got Axis installed and working--now it is time to add your own Web Service.

The process here boils down to (1) get the classes and libraries of your new service into the Axis WAR directory tree, and (2) tell the AxisEngine about the new file. The latter is done by submitting an XML deployment descriptor to the service via the Admin web service, which is usually done with the AdminClient program or the <axis-admin> Ant task. Both of these do the same thing: they run the Axis SOAP client to talk to the Axis administration service, which is a SOAP service in its own right. It's also a special SOAP service in one regard--it is restricted to local callers only (not remote access) and is password protected to stop random people from administrating your service. There is a default password that the client knows; if you change it then you need to pass the new password to the client.

The first step is to add your code to the server.

In the WEB-INF directory, look for (or create) a "classes" directory (i.e. axis/WEB-INF/classes ). In this directory, copy the compiled Java classes you wish to install, being careful to preserve the directory structure of the Java packages.

If your classes services are already packaged into JAR files, feel free to drop them into the WEB-INF/lib directory instead. Also add any third party libraries you depend on into the same directory.

After adding new classes or libraries to the Axis webapp, you must restart the webapp. This can be done by restarting your application server, or by using a server-specific mechanism to restart a specific webapp.

Note: If your web service uses the simple authorization handlers provided with xml-axis (this is actually not recommended as these are merely illustrations of how to write a handler than intended for production use), then you will need to copy the corresponding users.lst file into the WEB-INF directory.

Step 6: Deploying your Web Service

The various classes and JARs you have just set up implement your new Web Service. What remains to be done is to tell Axis how to expose this web service. Axis takes a Web Service Deployment Descriptor (WSDD) file that describes in XML what the service is, what methods it exports and other aspects of the SOAP endpoint.

The users guide and reference guide cover these WSDD files; here we are going to use one from the Axis samples: the stock quote service.

Classpath setup

In order for these examples to work, java must be able to find axis.jar, commons-discovery.jar, commons-logging.jar, jaxrpc.jar, saaj.jar, log4j-1.2.8.jar (or whatever is appropriate for your chosen logging implementation), and the XML parser jar file or files (e.g., xerces.jar). These examples do this by adding these files to AXISCLASSPATH and then specifying the AXISCLASSPATH when you run them. Also for these examples, we have copied the xml-apis.jar and xercesImpl.jar files into the AXIS_LIB directory. An alternative would be to add your XML parser's jar file directly to the AXISCLASSPATH variable or to add all these files to your CLASSPATH variable.

On Windows, this can be done via the following. For this document we assume that you have installed Axis in C:\axis. To store this information permanently in WinNT/2000/XP you will need to right click on "My Computer" and select "Properties". Click the "Advanced" tab and create the new environmental variables. It is often better to use WordPad to create the variable string and then paste it into the appropriate text field.

set AXIS_HOME=c:\axis

set AXIS_LIB=%AXIS_HOME%\lib

set AXISCLASSPATH=%AXIS_LIB%\axis.jar;%AXIS_LIB%\commons-discovery.jar;

  %AXIS_LIB%\commons-logging.jar;%AXIS_LIB%\jaxrpc.jar;%AXIS_LIB%\saaj.jar;

  %AXIS_LIB%\log4j-1.2.8.jar;%AXIS_LIB%\xml-apis.jar;%AXIS_LIB%\xercesImpl.jar

Unix users have to do something similar. Below we have installed AXIS into /usr/axis and are using the bash shell. See your shell's documentation for differences. To make variables permeate you will need to add them to your shell's startup (dot) files. Again, see your shell's documentation.

set AXIS_HOME=/usr/axis

set AXIS_LIB=$AXIS_HOME/lib

set AXISCLASSPATH=$AXIS_LIB/axis.jar:$AXIS_LIB/commons-discovery.jar:

  $AXIS_LIB/commons-logging.jar:$AXIS_LIB/jaxrpc.jar:$AXIS_LIB/saaj.jar:

  $AXIS_LIB/log4j-1.2.8.jar:$AXIS_LIB/xml-apis.jar:$AXIS_LIB/xercesImpl.jar

export AXIS_HOME; export AXIS_LIB; export AXISCLASSPATH

To use Axis client code, you can select AXISCLASSPATH when invoking Java by entering

java -cp %AXISCLASSPATH% ...

or

java -cp "$AXISCLASSPATH" ...

depending on the platform. You may omit the quotes if your CLASSPATH doesn't have spaces in it.

Also, it is probably a good time to add the AXISCLASSPATH variable to your CLASSPATH variable. This will enable you to not include the AXISCLASSPATH variable when launching the examples in this guide. This document assumes that you have NOT done this.

Find the deployment descriptor

Look in axis/samples/stock for the file deploy.wsdd. This is the deployment descriptor we want to tell Axis about. Deployment descriptors are an Axis-specific XML file that tells Axis how to deploy (or undeploy) a Web Service, and how to configure Axis itself. The Axis Administration Web Service lets the AdminClient program and its Ant task counterpart submit a new WSDD file for interpretation. The Axis 'engine' will update its configuration, then save its state.

By default Axis saves it state into the global configuration file axis/WEB-INF/server-config.wsdd. Sometimes you see a warning message about such a file not being found--don't worry about this, because Axis auto-creates the file after you deploy something to it. You can check in the webapp to see what this file looks like--and even copy it to other systems if you want to give them identical configurations. Note that Axis needs an expanded web application and write access to the WEB-INF dir to save its state in this location.

Run the admin client

Execute the following command from the samples/stock directory. If you are not in this directory you will get a "java.io.FileNotFoundException: deploy.wsdd (The system cannot find the file specified)" exception.

On Windows

java -cp %AXISCLASSPATH% org.apache.axis.client.AdminClient

     -lhttp://localhost:8080/axis/services/AdminService deploy.wsdd

On UNIX

java -cp $AXISCLASSPATH org.apache.axis.client.AdminClient

     -lhttp://localhost:8080/axis/services/AdminService deploy.wsdd

If you get some java client error (like ClassNotFoundException), then you haven't set up your AXISCLASSPATH (or CLASSPATH) variable right, mistyped the classname, or did some other standard error. Tracking down such problems are foundational Java development skills--if you don't know how to do these things, learn them now!

Note: You may need to replace localhost with your host name, and 8080 with the port number used by your web server. If you have renamed the web application to something other than "axis" change the URL appropriately.

If you get some AxisFault listing, then the client is working, but the deployment was unsuccessful. This is where the knowledge of the sockets API to TCP and the basics of the HTTP that Web Service development requires begins to be needed. If you got some socket error like connection refused, the computer at the far end isn't talking to you, so find the cause of that and fix it. If you get an HTTP error code back find out what the error means and correct the problem. These skills are fundamental to using web services.

The user's guide covers the AdminClient in more detail, and there is also an Ant task to automate the use of Axis in your Ant build scripts.

Step 7: Testing

This step is optional, but highly recommended. For illustrative purposes, it is presumed that you have installed and deployed the stock quote demo.

  • Change directory to the distribution directory for xml-axis and execute the following command (or its Unix equivalent):

On Windows

java -cp .;%AXISCLASSPATH% samples.stock.GetQuote

     -lhttp://localhost:8080/axis/servlet/AxisServlet

     -uuser1 -wpass1 XXX

On UNIX

java -cp $AXISCLASSPATH samples.stock.GetQuote

     -lhttp://localhost:8080/axis/servlet/AxisServlet

     -uuser1 -wpass1 XXX

  • You should get back "55.25" as a result.

Note: Again, you may need to replace localhost with your host name, and 8080 with the port number used by your web server. If you have renamed the web application to something other than "axis" change the URL appropriately.

Advanced Installation: adding Axis to your own Webapp

If you are experienced in web application development, and especially if you wish to add web services to an existing or complex webapp, you can take an alternate approach to running Axis. Instead of adding your classes to the Axis webapp, you can add Axis to your application.

The core concepts are

1.        Add axis.jar, wsdl.jar, saaj.jar, jaxrpc.jar and the other dependent libraries to your WAR file.

2.        Copy all the Axis Servlet declarations and mappings from axis/WEB-INF/web.xml and add them to your own web.xml

3.        Build and deploy your webapp.

4.        Run the Axis AdminClient against your own webapp, instead of Axis, by changing the URL you invoke it with.

The process is also covered in Chapter 15 of Java Development with Ant, which can be downloaded as a PDF file.

What if it doesn't work?

Axis is a complicated system to install. This is because it depends on the underlying functionality of your app server, has a fairly complex configuration, and, like all distributed applications, depends upon the network too.

We see a lot of people posting their problems on the axis-user mailing list, and other Axis users as well as the Axis developers do their best to help when they can. But before you rush to post your own problems to the mailing list, a word of caution:

Axis is free. This means nobody gets paid to man the support lines. All the help you get from the community is voluntary and comes from the kindness of their hearts. They may be other users, willing to help you get past the same hurdles they had to be helped over, or they may be the developers themselves. But it is all voluntary, so you may need to keep your expectations low!

1.        Post to the user mail list, not the developer list. You may think the developer mail list is a short cut to higher quality answers. But the developers are also on the user list along with many other skilled users--so more people will be able to answer your questions. Also, it is helpful for all user issues to be on one list to help build the searchable mailing list archive.

2.        Don't ask non-Axis-related questions. The list is not the place to ask about non-Axis, non-SOAP, problems. Even questions about the MS Soap toolkit or .NET client side, don't get many positive answers--we avoid them. That also goes for the Sun Java Web Services Developer Pack, or the Jboss.net stuff that they've done with Axis.

3.        Never bother posting to the soapbuilders mailing list either, that is only for people developing SOAP toolkits, not using them--all off-topic messages are pointedly ignored.

4.        There is no guarantee that anyone will be able to solve your problem. The usual response in such a situation is silence, for a good reason: if everybody who didn't know the answer to a question said "I don't know", the list would be overflowed with noise. Don't take silence personally.

5.        Never expect an immediate answer. Even if someone knows the answer, it can take a day or two before they read their mail. So if you don't get an answer in an hour or two, don't panic and resend. Be patient. And put the time to use by trying to solve your problems yourself.

6.        Do your homework first. This document lists the foundational stuff you need to understand. It has also warned you that it can take a day to get a reply. Now imagine you get a HTTP Error '404' on a SOAP call. Should you rush to post a 'help' request, or should you try and find out what an HTTP error code is, what #404 usually means and how to use a Java debugger. We provide the source to make that debugging easier :)

7.        Post meaningful subject lines. You want your message read, not deleted unread. A subject line of 'Axis problem', 'Help with Axis', etc. is not meaningful, and is not likely to get many readers.

8.        Search the mailing list archives FIRST to see if someone had the same problem. This list is searchable--and may save you much time in getting an answer to your problem.

9.        Use the jira database to search for Axis bugs, both open and closed.

10.     Consult the Axis Wiki for its Frequently Asked Questions (FAQ), installation notes, interoperability issues lists, and other useful information.

11.     Don't email people for help directly, unless you know them. It's rude and presumptuous. Messages sent over the mail list benefit the whole community--both the original posters and people who search the list. Personal messages just take up the recipients time, and are unwelcome. Usually, if not ignored outright, recipients of personal requests will just respond 'ask the mail list' anyway!

12.     Know that configuration problems are hard to replicate, and so can be difficult to get help on. We have tried with the happyaxis.jsp demo to automate the diagnostics gathering for you, but it can be hard for people to be of help here, especially for obscure platforms.

13.     Keep up to date with Axis releases, even the beta copies of forthcoming releases. You wouldn't want your problem to be a bug that was already known and fixed in a more recent release. Often the common response to any question is 'have you tried the latest release'.

14.     Study and use the source, and fix it when you find defects. Even fix the documentation when you find defects. It is only through the participation of Axis' users that it will ever get better.

Has this put you off joining and participating in the Axis user mail list? We hope not--this list belongs to the people who use Axis and so will be your peers as your project proceeds. We just need for you to be aware that it is not a 24x7 support line for people new to server side Java development, and that you will need to be somewhat self sufficient in this regard. It is not a silver bullet. However, knowing how to make effective use of the list will help you develop better with Axis.

Summary

Axis is simply an implementation of SOAP which can be added to your own webapp, and a webapp which can host your own web services. Installing it can be a bit fiddly, especially given Java 1.4's stricter requirements. If you follow a methodical process, including testing along the way, using happyaxis and the bundled test services, you will find it easier to get started with Axis.

Appendix: Enabling the SOAP Monitor

SOAP Monitor allows for the monitoring of SOAP requests and responses via a web browser with Java plug-in 1.3 or higher. For a more comprehensive explanation of its usage, read Using the SOAP Monitor in the User's Guide.

By default, the SOAP Monitor is not enabled. The basic steps for enabling it are compiling the SOAP Monitor java applet, deploying the SOAP Monitor web service and adding request and response flow definitions for each monitored web service. In more detail:

1.        Go to $AXIS_HOME/webapps/axis (or %AXIS_HOME%\webapps\axis) and compile SOAPMonitorApplet.java.

On Windows

javac -classpath %AXIS_HOME%\lib\axis.jar SOAPMonitorApplet.java

On Unix

javac -classpath $AXIS_HOME/lib/axis.jar SOAPMonitorApplet.java

2.    Copy all resulting class files (i.e. SOAPMonitorApplet*.class) to the root directory of the web application using the SOAP Monitor (e.g. .../tomcat/webapps/axis)

3.        Deploy the SOAPMonitorService web service with the admin client and the deploy-monitor.wsdd file (shown below).

Go to the directory deploy-monitor.wsdd is located and execute the command below. The command assume that /axis is the intended web application and it is available on port 8080.

On Windows

java -cp %AXISCLASSPATH% org.apache.axis.client.AdminClient

     -lhttp://localhost:8080/axis/services/AdminService deploy-monitor.wsdd

On UNIX

java -cp $AXISCLASSPATH org.apache.axis.client.AdminClient

     -lhttp://localhost:8080/axis/services/AdminService deploy-monitor.wsdd

SOAPMonitorService Deployment Descriptor (deploy-monitor.wsdd)

<deployment xmlns="http://xml.apache.org/axis/wsdd/"

            xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">

  <handler name="soapmonitor"

           type="java:org.apache.axis.handlers.SOAPMonitorHandler">

    <parameter name="wsdlURL"

               value="/axis/SOAPMonitorService-impl.wsdl"/>

    <parameter name="namespace"

               value="http://tempuri.org/wsdl/2001/12/SOAPMonitorService-impl.wsdl"/>

    <parameter name="serviceName" value="SOAPMonitorService"/>

    <parameter name="portName" value="Demo"/>

  </handler>

  <service name="SOAPMonitorService" provider="java:RPC">

    <parameter name="allowedMethods" value="publishMessage"/>

    <parameter name="className"

               value="org.apache.axis.monitor.SOAPMonitorService"/>

    <parameter name="scope" value="Application"/>

  </service>

</deployment>

4.        For each service that is to be monitored, add request and response flow definitions to the service's deployment descriptor and deploy (or redeploy) the service. The requestFlow and responseFlow definitions follow the start tag of the <service> element. If a service is already deployed, undeploy it and deploy it with the modified deployment descriptor. An example is shown below:

5.              ...

6.                 <service name="xmltoday-delayed-quotes" provider="java:RPC">

7.                   <requestFlow>

8.                     <handler type="soapmonitor"/>

9.                   </requestFlow>

10.                <responseFlow>

11.                  <handler type="soapmonitor"/>

12.                </responseFlow>

       ...

13.     With a web browser, go to http[s]://host[:port][/webapp]/SOAPMonitor (e.g. http://localhost:8080/axis/SOAPMonitor) substituting the correct values for your web application. This will show the SOAP Monitor applet for viewing service requests and responses. Any requests to services that have been configured and deployed correctly should show up in the applet.