JAX-WS - SOAP Handlers

What is SOAP Handlers ?

 SOAP Handlers are interceptor to do additional processing of incoming and outgoing message at Client as well as Server level. For example, to check properties in handler, to audit req/response or to do any filtering.

 SOAP message contains three parts as below:-
  1. SOAP Header [Optional]
  2. SOAP Body
  3. Attachments [Optional]
JAX-WS 2.0 defines 2 types of Handlers - Logical and Message Handler.
  • Logical Handlers operates on message context properties and message payload only. Logical handlers are handlers that implements - javax.xml.ws.handler.LogicalHandler
  • Message Handlers operates all parts of SOAP, i.e. SOAP Header, Body and attachments. it implements - javax.xml.ws.handler.soap.SOAPHandler
There are three methods of handlers as follows:-
  1. handleMessage() - This method is called for both incoming and outgoing message for any additional processing
  2. handleFault() - This handles any fault generated by service implementation or exception generated from above method
  3. close() - called at last to do clean up resources.
Flow of SOAP Handler invocations: 

Senders
  -> Logical Handler
     -> Message Handler
        -> Transport [HTTP?]
           -> Message Handler
               -> Logical handler 
                   -> Receiver

 Example:
Let us explore small web service example - echoservice, there are 2 handlers - one is checking for soap header parameter and second one is logging request / response console.
EchoServiceInterface.java   
 package soap.handler;  
   
 import javax.jws.WebParam;  
 import javax.jws.WebService;  
 import javax.jws.soap.SOAPBinding;  
 import javax.jws.soap.SOAPBinding.Style;  
   
 @WebService  
 @SOAPBinding(style = Style.DOCUMENT)  
 public interface EchoServiceInterface {  
   
      String getMessage(@WebParam(name = "message") String message);  
 }
EchoServiceImpl.java
 package soap.handler;  
   
 import javax.jws.HandlerChain;  
 import javax.jws.WebService;  
   
 @WebService(endpointInterface = "soap.handler.EchoServiceInterface")  
 @HandlerChain(file = "handlers.xml")  
 public class EchoServiceImpl implements EchoServiceInterface {  
   
      @Override  
      public String getMessage(String message) {  
           return message;  
      }  
   
 }
EchoServiceExecutor.java
 package soap.handler;  
   
 import javax.xml.ws.Endpoint;  
   
 public class EchoServiceExecutor {  
   
      public static void main(String[] args) {  
           Endpoint.publish("http://localhost:8888/echo-service", new EchoServiceImpl());  
      }  
   
 }
ClientValidator.java  - Message Handler
 package soap.handler;  
   
 import java.util.Iterator;  
 import java.util.Set;  
   
 import javax.xml.namespace.QName;  
 import javax.xml.soap.Node;  
 import javax.xml.soap.SOAPBody;  
 import javax.xml.soap.SOAPConstants;  
 import javax.xml.soap.SOAPEnvelope;  
 import javax.xml.soap.SOAPException;  
 import javax.xml.soap.SOAPFault;  
 import javax.xml.soap.SOAPHeader;  
 import javax.xml.soap.SOAPMessage;  
 import javax.xml.ws.handler.MessageContext;  
 import javax.xml.ws.handler.soap.SOAPHandler;  
 import javax.xml.ws.handler.soap.SOAPMessageContext;  
 import javax.xml.ws.soap.SOAPFaultException;  
   
 public class ClientValidator implements SOAPHandler<SOAPMessageContext> {  
   
      private String SERVICE_CONSUMER = "serviceconsumer";  
   
      @Override  
      public boolean handleMessage(SOAPMessageContext context) {  
             
   
           Boolean outboundProperty = (Boolean) context.get(MessageContext.MESSAGE_OUTBOUND_PROPERTY);  
   
           // incoming request  
           if (!outboundProperty) {  
                System.out.println("Client Request...");  
                checkMessage(context);  
           }else{  
                System.out.println("Client Response...");  
           }  
           return true;  
      }  
   
      // Check ConsumerApplication  
      private boolean checkMessage(SOAPMessageContext context) {  
           try {  
                SOAPMessage soapMessage = context.getMessage();  
                SOAPEnvelope soapEnvelope = soapMessage.getSOAPPart().getEnvelope();  
                SOAPHeader soapHeader = soapEnvelope.getHeader();  
   
                Iterator<?> headers = soapHeader.extractHeaderElements(SOAPConstants.URI_SOAP_ACTOR_NEXT);  
   
                if (headers != null && headers.hasNext()) {  
                     Node node = (Node) headers.next();  
   
                     if (node != null) {  
                          if (!SERVICE_CONSUMER.equals(node.getNodeName())) {  
                               System.out.println("Missing ServiceConsumer Header");  
                               SOAPBody soapBody = soapMessage.getSOAPPart().getEnvelope().getBody();  
                               SOAPFault soapFault = soapBody.addFault();  
                               soapFault.setFaultString("Invalid Service Consumer..!!");  
                                 
                               throw new SOAPFaultException(soapFault);  
                          }  
                     }  
                }  
   
           } catch (SOAPException e) {  
                System.err.println(e);  
           }  
           return true;  
   
      }  
   
      @Override  
      public boolean handleFault(SOAPMessageContext context) {  
           return false;  
      }  
   
      @Override  
      public void close(MessageContext context) {  
   
      }  
   
      @Override  
      public Set<QName> getHeaders() {  
           return null;  
      }  
   
 }
LoggingHandler.java - Logical handler
 package soap.handler;  
   
 import javax.xml.transform.Source;  
 import javax.xml.ws.LogicalMessage;  
 import javax.xml.ws.handler.LogicalHandler;  
 import javax.xml.ws.handler.LogicalMessageContext;  
 import javax.xml.ws.handler.MessageContext;  
   
 public class LoggingHandler implements LogicalHandler<LogicalMessageContext> {  
   
      @Override  
      public boolean handleMessage(LogicalMessageContext context) {  
   
           Boolean outboundProperty = (Boolean) context.get(MessageContext.MESSAGE_OUTBOUND_PROPERTY);  
   
           if (outboundProperty.booleanValue()) {  
                System.out.println("Response:-");  
           } else {  
                System.out.println("Request:-");  
           }  
   
           LogicalMessage message = context.getMessage();  
   
           try {  
                Source src = message.getPayload();  
                Utility.print(src);  
           } catch (Exception e) {  
                System.err.println(e);  
           }  
   
           return true;  
      }  
   
      @Override  
      public boolean handleFault(LogicalMessageContext context) {  
           return false;  
      }  
   
      @Override  
      public void close(MessageContext context) {  
   
      }  
   
 }
handlers.xml
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>  
 <javaee:handler-chains xmlns:javaee="http://java.sun.com/xml/ns/javaee"  
      xmlns:xsd="http://www.w3.org/2001/XMLSchema">  
      <javaee:handler-chain>  
           <javaee:handler>  
                <javaee:handler-class>soap.handler.ClientValidator  
                </javaee:handler-class>  
           </javaee:handler>  
           <javaee:handler>  
                <javaee:handler-class>soap.handler.LoggingHandler  
                </javaee:handler-class>  
           </javaee:handler>  
      </javaee:handler-chain>  
 </javaee:handler-chains>
soap-ui Request / Response
 <soapenv:Envelope   
 xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:han="http://handler.soap/">  
   <soapenv:Header>   
        <serviceconsumer soapenv:actor="http://schemas.xmlsoap.org/soap/actor/next">Application</serviceconsumer>  
   </soapenv:Header>  
   <soapenv:Body>  
    <han:getMessage>  
      <message>Demo Application</message>  
    </han:getMessage>  
   </soapenv:Body>  
 </soapenv:Envelope>  


 <S:Envelope xmlns:S="http://schemas.xmlsoap.org/soap/envelope/">  
   <S:Body>  
    <ns2:getMessageResponse xmlns:ns2="http://handler.soap/">  
      <return>Demo Application</return>  
    </ns2:getMessageResponse>  
   </S:Body>  
 </S:Envelope>
Console Output 
 Client Request...  
 Request:-  
 <?xml version="1.0" encoding="UTF-8"?><han:getMessage xmlns:han="http://handler.soap/" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">  
      <message>Demo Application</message>  
    </han:getMessage>  
 Response:-  
 <?xml version="1.0" encoding="UTF-8"?><ns2:getMessageResponse xmlns:ns2="http://handler.soap/"><return>Demo Application</return></ns2:getMessageResponse>  
 Client Response...

Download Example

Comments

Post a Comment

Popular posts from this blog

Create BeanShell Script to Make Database call

BeanShell Script BeanShell is a small, free, embeddable Java source interpreter with object scripting language features, written in Java. BeanShell dynamically executes standard Java syntax and extends it with common scripting conveniences such as loose types, commands, and method closures like those in Perl and JavaScript. Following script make database connection and every iteration it takes 50 records from database and populate them in hashmap. This has been created to use with jmeter using beanshell sampler. import com.postgresql.jdbc.Driver; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import java.util.HashMap; import java.util.Map; System.out.println("Postgres Connect Example."); Connection conn = null; Statement stmt = null; ResultSet rs = null; String url = "jdbc:postgresql://192.168.3.99:5432/"; String dbName = "DB";
Read more

Connection Pooling

Image
Connection pooling, but what it is and what it do ? It is set of database connections that can be used in future.  This connection can be used across many sessions, once execution completes, it returns connection to connection pool.   Source: docs.oracle.com It will boost performance, because creating connection for every-user and action it will degrade performance, So how can we add connection pooling in java. Hibernate configuration using c3p0 hibernate.connection.driver_class=com.mysql.jdbc.Driver hibernate.connection.url=jdbc:mysql://localhost/connectionpool hibernate.connection.username=root hibernate.connection.password=<password> hibernate.dialect=net.sf.hibernate.dialect.MySQLDialect hibernate.show_sql=false hibernate.c3p0.max_size=1 hibernate.c3p0.min_size=0 hibernate.c3p0.timeout=5000 hibernate.c3p0.max_statements=100 hibernate.c3p0.idle_test_period=300 hibernate.c3p0.acquire_increment=2 For more information, che
Read more