Sunil's Notes: October 2011

Createing Hello JAXRS service for deployment using Sun Jersey

If you want to build a REST service and deploy it in one of the Java EE 5 compliant containers for example WebSphere APplication Server 7.0, then you will have to use one of the external JAXRS containers such as Jersey, which is very popular among REST service developers.

I wanted to try this option out so i built a HelloJersey application that you can download from here. I followed these steps for building my sample application

First create a Dynamic Web APplication project called HelloJersey

Download following .jar files and add it to the WEB-INF/lib folder of your web application
1. asm-3.1.jar
2. jersey-core-1.5.jar
3. jersey-server-1.5.jar
4. jsr311-api-1.1.1.jar

Next create a HelloJerseyRESTService.java file like this


package com.webspherenotes.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;

@Path("/hellojersey")
public class HelloJerseyRESTService {

  @GET
  @Produces(MediaType.TEXT_HTML)
  public String sayHello(@QueryParam("name") String name ){
    return "Hello " + name;
  }
}

The HelloJerseyRESTService only handles GET request and returns HTML markup

Next declare the Jersey servlet in the web.xml and create servlet mapping


<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.5"
  xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name>DynaCacheSample1</display-name>
  <servlet>
    <servlet-name>Jersey REST Service</servlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
    <init-param>
      <param-name>com.sun.jersey.config.property.packages</param-name>
      <param-value>com.webspherenotes.rest</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>Jersey REST Service</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>  
    <welcome-file-list>
      <welcome-file>index.html</welcome-file>
      <welcome-file>index.htm</welcome-file>
      <welcome-file>index.jsp</welcome-file>
      <welcome-file>default.html</welcome-file>
      <welcome-file>default.htm</welcome-file>
      <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>
</web-app>

After you deploy the application in container you should see that when the server is starting it will scan all the resource and in our case it should find only com.webspherenotes.rest.HelloJerseyRESTService
[10/16/11 17:17:47:250 PDT] 0000000e ApplicationMg I WSVR0228I: User initiated module stop operation request completed on Module, HelloJersey.war, of application, DynaCacheSample1EAR [10/16/11 17:17:49:932 PDT] 0000000e ApplicationMg I WSVR0225I: User initiated module start operation requested on Module, HelloJersey.war, of application, DynaCacheSample1EAR [10/16/11 17:17:50:466 PDT] 0000000e webapp I com.ibm.ws.webcontainer.webapp.WebGroupImpl WebGroup SRVE0169I: Loading Web Module: HelloJersey. [10/16/11 17:17:50:521 PDT] 0000000e WASSessionCor I SessionContextRegistry getSessionContext SESN0176I: Will create a new session context for application key default_host/HelloJersey [10/16/11 17:17:50:602 PDT] 0000000e PackagesResou I Scanning for root resource and provider classes in the packages: com.webspherenotes.rest [10/16/11 17:17:50:666 PDT] 0000000e ScanningResou I Root resource classes found: class com.webspherenotes.rest.HelloJerseyRESTService [10/16/11 17:17:50:667 PDT] 0000000e ScanningResou I No provider classes found. [10/16/11 17:17:50:850 PDT] 0000000e WebApplicatio I Initiating Jersey application, version 'Jersey: 1.5 01/14/2011 12:36 PM' [10/16/11 17:17:51:816 PDT] 0000000e servlet I com.ibm.ws.webcontainer.servlet.ServletWrapper init SRVE0242I: [DynaCacheSample1EAR] [/HelloJersey] [Jersey REST Service]: Initialization successful. [10/16/11 17:17:51:817 PDT] 0000000e webcontainer I com.ibm.ws.wswebcontainer.VirtualHost addWebApplication SRVE0250I: Web Module HelloJersey has been bound to default_host[*:9080,*:80,*:9443,*:5060,*:5061,*:443]. [10/16/11 17:17:51:824 PDT] 0000000e ApplicationMg I WSVR0226I: User initiated module start operation request completed on Module, HelloJersey.war, of application, DynaCacheSample1EAR [10/16/11 17:17:51:825 PDT] 0000000e AppBinaryProc I ADMA7021I: Distribution of application DynaCacheSample1EAR completed successfully.

You can test the service by either directly going to the http://localhost:9080/HelloJersey/rest/hellojersey?name=sunil URL or using the REST client

Create Hello JAX-RS service in WAS 8.0

The WAS 8.0 is Java EE 6.0 compliant that means it allows you to deploy JAX-RS compliant service and you dont have to go through painful steps for setting up external JAXRS container such as Jersey in your web application

I wanted to figure out what it takes to create HelloREST application in WAS 8.0 so i followed this steps to create Hello JAX-RS service. You can download the source code for sample from here

First i used RAD 8.0 to create Servlet Technology 3.0 compliant web application( Which means no need for web.xml or no need of declaring servlets)

Next create a HelloRestService class that is basically a REST service and is available at /hellorest url


package com.webspherenotes.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;

@Path("/hellorest")
public class HelloRESTService {

  @GET
  @Produces("text/html")
  public String sayHello(@QueryParam("name") String name){
    return "Hello " + name;
  }
  
}

Next create HelloApplication class which is basically a REST servlet class like this.


package com.webspherenotes.rest;

import java.util.HashSet;
import java.util.Set;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;

@ApplicationPath("/rest/")
public class HelloApplication extends Application{

  @Override
  public Set<Class<?>> getClasses() {
     Set<Class<?>> s = new HashSet<Class<?>>();
     s.add(HelloRESTService.class);
     return s;
  }
  
}

The HelloApplication class extends javax.ws.rs.core.Application which helps you to declare the JAX-RS application, in this class i am overriding the getClasses() method which returns set of JAX-RS classes that act as JAX-RS service. In my case i do have only one HelloRESTService class so i am only adding that

Now deploy the application on your WAS 8.0 server, if you try accessing it by sending GET request to http://localhost:9080/HelloRESTService/rest/hellorest?name=Sunil URL and you should get Hello Sunil as response

Pretty printing SOAP messages

If your dealing with SAAJ API or you want to create a Debug Message Handler that prints the SOAP Message then you can call SOAPmessage.writeTo(System.out), but this method writes the full SOAP message in one line and which can be little hard to read this is sample output


<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"><SOAP-ENV:Body><wn:sayHello SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:wn="http://ws.websphrenotes.com/"><arg0>Sunil</arg0></wn:sayHello></SOAP-ENV:Body></SOAP-ENV:Envelope>

If you want to pretty print the SOAPMessage then you can use the following method.


package com.webspherenotes.ws;
import java.io.ByteArrayOutputStream;

import javax.xml.soap.SOAPMessage;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
public class SOAPHelper {
   public static String getSOAPMessageAsString(SOAPMessage soapMessage) {
      try {

         TransformerFactory tff = TransformerFactory.newInstance();
         Transformer tf = tff.newTransformer();

         // Set formatting
        
         tf.setOutputProperty(OutputKeys.INDENT, "yes");
         tf.setOutputProperty("{http://xml.apache.org/xslt}indent-amount",
               "2");
         
         Source sc = soapMessage.getSOAPPart().getContent();

         ByteArrayOutputStream streamOut = new ByteArrayOutputStream();
         StreamResult result = new StreamResult(streamOut);
         tf.transform(sc, result);

         String strMessage = streamOut.toString();
         return strMessage;
      } catch (Exception e) {
         System.out.println("Exception in getSOAPMessageAsString "
               + e.getMessage());
         return null;
      }

   }
}

It generates the output which looks like this


<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
  <SOAP-ENV:Body>
    <wn:sayHello SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:wn="http://ws.websphrenotes.com/">
      <arg0>Sunil</arg0>
    </wn:sayHello>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

I ended up doing this because i could not find SaajOutputer.java class

Updating WAS 8

In the Installing WAS 8 Beta on your machine, entry i talked about how IBM has changed the way we installed WebSphere Application Server starting from V8.0. Now we have to use the IBM Installation Manager,

One advantage of using the IBM Installation manager for installing/managing the WAS 8.0 is that updating it has become very easy, I had to use simple wizard to install latest WAS 8.0 recommended fixes on my machine, no need to go through the process of finding recommended fixes, downloading them and the using update installer to install fixes.