Differences between wsimport and wsgen


wsimport:

  • The wsimport tool reads a WSDL and generates all the required artifacts for web service development, deployment, and invocation.
  • It supports the top-down approach to developing JAX-WS Web services, where you are starting from a wsdl.
  • wsimport tool generated JAX-WS portable artifacts include Service Endpoint Interface (SEI), Service, Exception class mapped from wsdl:fault (if any), JAXB generated value types (mapped java classes from schema types) etc. These artifacts can be packaged in a WAR file with the WSDL and schema documents along with the endpoint implementation to be deployed.

Ex Command :

wsimport http://localhost:8090/MyJaxWSService?wsdl

wsgen:
The wsgen tool reads an existing web service implementation class and generates the required JAX–WS portable artifacts for web service development and deployment. The wsgen tool can be used for bottoms-up approach, where you are starting from a service endpoint implementation rather than a wsdl.

Ex Command :

wsgen -verbose -keep -cp . in.malliktalksjava.service.HellowWorldService
  • wsgen and wsimport generate request and response wrapper bean classes and the JAXB classes. However, wsgen generates the JAXB classes and put them in a jaxws folder and wsimport does not put those classes in any folder instead they will be placed in the current directory.
  • JAX-WS artifacts generated can be used by both service implementation and client implementation.
  • Using wsgen you can also generate the wsdl based on webservice implementation class.

Create web service in Bottom Up approach using command line


Create Service Interface MyJaxWSSEI.java

package in.malliktalksjava.ws;

import in.malliktalksjava.ws.pojo.*;

import javax.jws.WebMethod;
import javax.jws.WebParam;
import javax.jws.WebResult;
import javax.jws.WebService;
import javax.jws.WebParam.Mode;
import javax.jws.soap.SOAPBinding;
import javax.jws.soap.SOAPBinding.Style;
import javax.jws.soap.SOAPBinding.Use;
import javax.xml.ws.RequestWrapper;
import javax.xml.ws.ResponseWrapper;

@WebService(name = “MyJaxWSHello”,
targetNamespace = “http://malliktalksjava.in”,
wsdlLocation = “http://malliktalksjava.in/MyJaxWS?wsdl”)
@SOAPBinding(style=Style.RPC, use=Use.LITERAL)
public interface MyJaxWSSEI {

@WebMethod(operationName=”getJXWsRes”)
@RequestWrapper(targetNamespace=”http://malliktalksjava.in/ws/types”,
className=”java.lang.String”)
@ResponseWrapper(targetNamespace=”http://malliktalksjava.in/ws/types”,
className=”in.malliktalksjava.ws.JXRes”)
@WebResult(targetNamespace=”http://malliktalksjava.in/ws/types”,
name=”JXWsRes”)
public JXRes getJXWsRes(
@WebParam(targetNamespace=”http://malliktalksjava.in/ws/types”,
name=”name”,
mode=Mode.IN)
String name
);

}

 

Create Implementation class for the above interface – MyJaxWSSEIImpl.java

package in.malliktalksjava.ws;

import in.malliktalksjava.ws.pojo.*;
import javax.jws.WebService;

@WebService(endpointInterface=”in.malliktalksjava.ws.MyJaxWSSEI”,
targetNamespace=”http://malliktalksjava.in”,
portName=”MyJaxWSSEIPort”,
serviceName=”MyJaxWSHelloService”)
public class MyJaxWSSEIImpl implements MyJaxWSSEI {

/**
* Default Constructor
*/
public MyJaxWSSEIImpl() {

}

/* (non-Javadoc)
* @see in.malliktalksjava.ws.MyJaxWSSEI#getJXWsRes(java.lang.String)
*/
@Override
public JXRes getJXWsRes(String name) {
JXRes jxRes = new JXRes();
jxRes.setMessage(“Hello”);
jxRes.setName(name);
return jxRes;
}

}

Create Required Model object JXRes.java

package in.malliktalksjava.ws.pojo;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class JXRes {
protected String message;
protected String name;
/**
*
*/
public JXRes() {
super();
}
/**
* @return the id
*/
public String getMessage() {
return message;
}
/**
* @param id the id to set
*/
public void setMessage(String message) {
this.message = message;
}
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}

}

Create Main Class JXResTest.java

package in.malliktalksjava.ws.main;

import javax.xml.ws.Endpoint;
import in.malliktalksjava.ws.*;

public class JXResTest {
public static void main(String[] args ){
Endpoint.publish(“http://localhost:8080/MyJaxWSService”, new MyJaxWSSEIImpl());
}
}

 

Compile Java Classes in command prompt:

compileclass

Run the class

runmainclass

Verify the service : http://localhost:8080/MyJaxWSService?wsdl

wsdl

 

SOAP Vs REST Web Services


SOAP REST
1) SOAP is a protocol. REST is an architectural style.
2) SOAP stands for Simple Object Access Protocol. REST stands for REpresentational State Transfer.
3) SOAP can’t use REST because it is a protocol. REST can use SOAP web services because it is a concept and can use any protocol like HTTP, SOAP.
4) SOAP uses services interfaces to expose the business logic. REST uses URI to expose business logic.
5) JAX-WS is the java API for SOAP web services. JAX-RS is the java API for RESTful web services.
6) SOAP defines standards to be strictly followed. REST does not define too much standards like SOAP.
7) SOAP requires more bandwidth and resource than REST. REST requires less bandwidth and resource than SOAP.
8) SOAP defines its own security. RESTful web services inherits security measures from the underlying transport.
9) SOAP permits XML data format only. REST permits different data format such as Plain text, HTML, XML, JSON etc.
10) SOAP heavy weight operation. REST is light weight and suggested to use in lower band with scenarios such as accessing applications using mobile devices.
11) SOAP is less preferred than REST. REST more preferred than SOAP.

Difference between HttpSession’s getSession(), getSession(true) and getSession(false) methods


  • getSession() : Returns the current session associated with this request, or if the request does not have a session, creates one.
  • getSession(true) : Returns the current HttpSession associated with this request, if there is no current session, returns a new session
  • getSession(false) : Returns the current HttpSession associated with this request, if there is no current session, returns null.

Basic MQ Commands


1. Create/start/stop a Queue Manager

crtmqm [-z] [-q] [-c Text] [-d DefXmitQ] [-h MaxHandles]
[-g ApplicationGroup] [-t TrigInt]
[-u DeadQ] [-x MaxUMsgs] [-lp LogPri] [-ls LogSec]
[-lc | -ll] [-lf LogFileSize] [-ld LogPath] QMgrName

Output :

WebSphere MQ queue manager created.
Creating or replacing default objects for QMA.
Default objects statistics : 43 created. 0 replaced. 0 failed.
Completing setup.
Setup completed.

2. Starting a Queue Manager

$ strmqm QMA

Output:

WebSphere MQ queue manager ‘QMA’ starting.
2108 log records accessed on queue manager ‘QMA’ during the log
replay phase.
Log replay for queue manager ‘QMA’ complete.
Transaction manager state recovered for queue manager ‘QMA’.
WebSphere MQ queue manager ‘QMA’ started.

3. Checking that the Queue Manager is running

$ dspmq

Output :

QMNAME(QMA) STATUS(Running)

4. Stopping a Queue Manager

$ endmqm –i QMA

5. Deleting a Queue Manager

The following command will stop all the Listeners associated with Queue Manager pointed to by the –m flag (QMA in this example). The –w flag means the command will wait until all the Listeners are stopped before returning control:

$ endmqlsr -w -m QMA

The command to stop (end) the Queue Manager is:

$ endmqm QMA

And fnally the command to delete the Queue Manager is:

$ dltmqm QMA

 

Other Useful Links:

Enable JMX Remote port in WebSphere

 

Create a Java web service using top down approch


In the bottom up approach, we will write the java class and generates the WSDL file and other dependent components. The same will be deployed into the web containers.

In Top down approach, Architects will write the WSDL file based on the requirements. Developer need to make the corresponding service implementation using the WSDL provided. This post will explain how to create a service using the WSDL file.

Step 1: Create a dynamic or java project as mentioned here

Here, I have created a sample web dynamic project with the name SampleWS as given below.

Dyanmic web project

Step 2: generate the service using top down approach

Right click on the SamplWS project name -> New -> Other

SelectOther

Select the Web Service from the wizard as below and click on Finish button.

select webservice

Select the Web service type as ‘Top down Java bean Web service’ and provide the WSDL url in the Service definition drop down and click on Finish button.

Sample WSDL URL is: http://localhost:8080/SampleWebService/wsdl/Calculator.wsdl

providethewsdl

Your Web service is ready with the Java bean methods as below and the Final folder structure looks like below:

service Folder structure

Write the business logic into the Service class as given below:

Generated class:

/**
* CalculatorSoapBindingImpl.java
*
* This file was auto-generated from WSDL
* by the Apache Axis 1.4 Apr 22, 2006 (06:55:48 PDT) WSDL2Java emitter.
*/

package in.malliktalksjava;

public class CalculatorSoapBindingImpl implements in.malliktalksjava.Calculator{
public int addition(int var1, int var2) throws java.rmi.RemoteException {
return -3;
}

public int multiplication(int var1, int var2) throws java.rmi.RemoteException {
return -3;
}

public int division(int var1, int var2) throws java.rmi.RemoteException {
return -3;
}

}

Implemented class:

/**
* CalculatorSoapBindingImpl.java
*
* This file was auto-generated from WSDL
* by the Apache Axis 1.4 Apr 22, 2006 (06:55:48 PDT) WSDL2Java emitter.
*/

package in.malliktalksjava;

public class CalculatorSoapBindingImpl implements in.malliktalksjava.Calculator{
public int addition(int var1, int var2) throws java.rmi.RemoteException {
return var1+var2;
}

public int multiplication(int var1, int var2) throws java.rmi.RemoteException {
return var1*var2;
}

public int division(int var1, int var2) throws java.rmi.RemoteException {
return var1/var2;
}

}

Deploy the application into server and use the below url as a WSDL for this to have the client.

http://localhost:8080/SampleWebService/wsdl/Calculator.wsdl

 

Other Useful Links:

 Click here to know more about webservices

Click here to know more about RESTfull web services.

Click here for Web services Question and Answers.

Click here to know how to write web service client suing java.

Write a Client for web service


Below steps explains how to write a web service client in java using STS IDE.

Step 1: Create a Java project using the steps mentioned here.

Step 2: Generate the stubs for the Java web service using below steps

Mouse Right click on Client project and select New -> Other

select other option

Select the Web service client from the wizard

Select webservice cliet

Provide the service WSDL url in the Service Definition text box and click on finish button.

Enterwsdl into service defination

Web service client stubs will be generated into the package and final folder structure looks below.

Client stubs generated

Write the Client class using the stubs and test the client project.

Write a client

 

Use the below sample code to write the client:

 

package in.malliktalksjava.client;

import java.rmi.RemoteException;

import in.malliktalksjava.Calculator;
import in.malliktalksjava.CalculatorServiceLocator;
import javax.xml.namespace.QName;
import javax.xml.rpc.ServiceException;

/**
* @author Javatutorials
* @since version 1.0
*
*/
public class SampleWSClient {

/**
* @param args
*/
public static void main(String[] args) {

SampleWSClient sc = new SampleWSClient();
sc.callCalculatorWebservice();
}

/**
* used to call web service
*/
public void callCalculatorWebservice(){

String wsdl = “http://localhost:8080/SampleWebService/wsdl/Calculator.wsdl”;
QName queue = new QName(“http://malliktalksjava.in”, “CalculatorService”);

try {
//create the servicelocator object
CalculatorServiceLocator calServiceLoc = new CalculatorServiceLocator(wsdl, queue);
//create the service object
Calculator calculator = calServiceLoc.getCalculator();
//call the service methods
System.out.println(“addition result : “+calculator.addition(10, 11));
System.out.println(“division result : “+calculator.division(10, 5));
System.out.println(“multiplication result : “+calculator.multiplication(10, 10));
} catch (ServiceException e) {
e.printStackTrace();
} catch (RemoteException e) {
e.printStackTrace();
}
}
}

 

With this your client application is ready to use.

 

Other Useful links:

Click here to know how to create the web service project.

Click here to know the difference between SOAP and RESTfull web services.