cURL simple load script

 curl -X PUT  -d@test.xml http://ppp.amazonaws.com/p[1-2000].xml &

pidlist="$pidlist $!" 

curl -X PUT  -d@a.xml http://qqq.amazonaws.com/q[1-2000].xml &

pidlist="$pidlist $!" 

 curl -X PUT  -d@b.xml http://rrr.amazonaws.com/r[1-2000].xml &

pidlist="$pidlist $!" 

curl -X PUT  -d@c.xml http://sss.amazonaws.com/s[1-2000].xml &

pidlist="$pidlist $!" 

 

for job in $pidlist do 

  echo $job     

  wait $job || let "FAIL+=1" 

done  

if [ "$FAIL" == "0" ]; then 

  echo "SUCCESS!" 

else 

  echo "FAIL! ($FAIL)" 

fi

Getting KeyCloakContext From ServletRequest

When REST APIs are protected with keycloak authentication, we might need to get user realm in the backend to get some user information.

In the ServletRequestFilter implementation,

public class ApplicationFilter implements Filter {

private Base64 decoder = new Base64(true);

        @Inject

ServletRequestHolder requestHolder;

@Override

public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)

throws IOException, ServletException {

try {

checkAuthentication(req);

....

//TODO

}

/**

* Get the logged in user info from the request.

* 

* @param request

*/

private void checkAuthentication(ServletRequest request) {

HttpServletRequest httpServletRequest = (HttpServletRequest) request;

KeycloakSecurityContext kContext = (KeycloakSecurityContext) httpServletRequest

.getAttribute(KeycloakSecurityContext.class.getName());

String bearerToken;

if (kContext != null) {

bearerToken = kContext.getTokenString();

String[] jwtToken = bearerToken.split("\\.");

byte[] decodedClaims = decoder.decode(jwtToken[1]);

JSONObject jsonObj = new JSONObject(new String(decodedClaims));

.....

//TODO

}

JAX-RS Custom Exception Mapper

When the service(backend) throws any custom exception, using <javax.ws.rs.ext.ExceptionMapper> we can catch it , and send a relevant message to the client (/caller).

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

/**
 * Map the server exceptions to return to the client
 *
 */

@Provider
public class CustomJaxRsExceptionMapper implements ExceptionMapper {

@Override

     @Produces("application/json")

public Response toResponse(ServiceException e) {

          Map map = new HashMap();

  map.put("Exception", e.getMessage());

Response response = Response.status(500).entity(map).build();
return response;
}
}

RESTEASY003875: Unable to find a constructor that takes a String param or a valueOf() or fromString() method

The error[1] occurs when we use complex types in our GET querys.  JAXRS understands simple data types. If we use complex types, we might need to have our own (de)serialisation for the complex types.

import java.lang.annotation.Annotation;

import java.lang.reflect.Type;

import java.math.BigDecimal;

import javax.money.Monetary;

import javax.ws.rs.ext.ParamConverter;

import javax.ws.rs.ext.ParamConverterProvider;

import javax.ws.rs.ext.Provider;

import org.javamoney.moneta.Money;

@Provider

public class MoneyConverterProvider  implements ParamConverterProvider {

    private final MoneyConverter converter = new MoneyConverter();

    @Override

    public ParamConverter getConverter(Class rawType, Type genericType, Annotation[] annotations) {

        if (!rawType.equals(Money.class)) return null;

        return (ParamConverter) converter; 

    }

    public class MoneyConverter implements ParamConverter {

        public Money fromString(String value) {

            if (value == null ||value.isEmpty()) return null; 

   

            return Money.of(new BigDecimal(value), Monetary.getCurrency("AUD"));

        }

        public String toString(Money value) {

            if (value == null) return "";

            return value.toString(); 

        }

    }

}

[1]


0:42:46,435 ERROR [org.jboss.msc.service.fail] (ServerService Thread Pool -- 86) MSC000001: Failed to start service jboss.undertow.deployment.default-server.default-host./apidb: org.jboss.msc.service.StartException in service jboss.undertow.deployment.default-server.default-host./apidb: java.lang.RuntimeException: RESTEASY003875: Unable to find a constructor that takes a String param or a valueOf() or fromString() method for javax.ws.rs.QueryParam("money") on public javax.ws.rs.core.Response com.rest.autogen.SalesTransactionEndpoint.getItems(java.lang.Integer,java.lang.Integer,java.lang.String,java.lang.Long,java.lang.String, org.javamoney.moneta.Money) for basetype: org.javamoney.moneta.Money

at org.wildfly.extension.undertow.deployment.UndertowDeploymentService$1.run(UndertowDeploymentService.java:85)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
at org.jboss.threads.JBossThread.run(JBossThread.java:320)
Caused by: java.lang.RuntimeException: RESTEASY003875: Unable to find a constructor that takes a String param or a valueOf() or fromString() method for javax.ws.rs.QueryParam("money") on public javax.ws.rs.core.Response com.rest.autogen.SalesTransactionEndpoint.getItems(java.lang.Integer,java.lang.Integer,java.lang.String,java.lang.Long,java.lang.String,org.javamoney.moneta.Money) for basetype: org.javamoney.moneta.Money
at org.jboss.resteasy.core.StringParameterInjector.initialize(StringParameterInjector.java:220)
at org.jboss.resteasy.core.StringParameterInjector.(StringParameterInjector.java:64)
at org.jboss.resteasy.core.QueryParamInjector.(QueryParamInjector.java:30)
at org.jboss.resteasy.core.InjectorFactoryImpl.createParameterExtractor(InjectorFactoryImpl.java:86)
at org.jboss.resteasy.cdi.CdiInjectorFactory.createParameterExtractor(CdiInjectorFactory.java:52)
at org.jboss.resteasy.core.MethodInjectorImpl.(MethodInjectorImpl.java:44)
at org.jboss.resteasy.core.InjectorFactoryImpl.createMethodInjector(InjectorFactoryImpl.java:77)
at org.jboss.resteasy.cdi.CdiInjectorFactory.createMethodInjector(CdiInjectorFactory.java:58)
at org.jboss.resteasy.core.ResourceMethodInvoker.(ResourceMethodInvoker.java:99)
at org.jboss.resteasy.core.ResourceMethodRegistry.processMethod(ResourceMethodRegistry.java:281)
at org.jboss.resteasy.core.ResourceMethodRegistry.register(ResourceMethodRegistry.java:252)
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:222)
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:194)
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:180)
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:157)
at org.jboss.resteasy.core.ResourceMethodRegistry.addPerRequestResource(ResourceMethodRegistry.java:76)
at org.jboss.resteasy.spi.ResteasyDeployment.registration(ResteasyDeployment.java:434)
at org.jboss.resteasy.spi.ResteasyDeployment.start(ResteasyDeployment.java:245)
at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.init(ServletContainerDispatcher.java:113)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.init(HttpServletDispatcher.java:36)
at io.undertow.servlet.core.LifecyleInterceptorInvocation.proceed(LifecyleInterceptorInvocation.java:117)
at org.wildfly.extension.undertow.security.RunAsLifecycleInterceptor.init(RunAsLifecycleInterceptor.java:78)
at io.undertow.servlet.core.LifecyleInterceptorInvocation.proceed(LifecyleInterceptorInvocation.java:103)
at io.undertow.servlet.core.ManagedServlet$DefaultInstanceStrategy.start(ManagedServlet.java:231)
at
io.undertow.servlet.core.ManagedServlet.createServlet(ManagedServlet.java:132)
at io.undertow.servlet.core.DeploymentManagerImpl.start(DeploymentManagerImpl.java:526)
at org.wildfly.extension.undertow.deployment.UndertowDeploymentService.startContext(UndertowDeploymentService.java:101)
at org.wildfly.extension.undertow.deployment.UndertowDeploymentService$1.run(UndertowDeploymentService.java:82)

Adding URL parameters in WSO2 APIManager

It is a common use case, where users might want to add URL parameters  which are evaluated dynamically in their endpoints.
We can use same approach what we do in ESB, but it may confuse users on how to implement it in APIManager.
APIManager supports adding custom sequences for the API mediation logic. There are few ways available to add custom mediation plugins.
One, which we can simply use for this requirement is, store the mediation logic in registry as a sequence and select that in the in/out flow of the API invocation when publishing API.

Eg:

If we want to invoke the API with something like(note: we pass PhoneNumber parameter)
http://localhost:8280/dimtry/1.0?PhoneNumber=+16506697051 and send to the backend: http://ws.cdyne.com/phoneverify/phoneverify.asmx/CheckPhoneNumber? PhoneNumber=+16506697051&LicenseKey=0"

In the above example, backend service expects two URL parameters for the GET call to return proper response. But user will pass only one parameter(i.e.: phone number). We need to extract that user parameter and within api mediation logic we need to add another license key parameter too.

To achieve this, When publish an API define HTTP endpoint with parameters and assign values to those parameters in the custom sequence.

Eg: <http uri-template=" http://ws.cdyne.com/phoneverify/phoneverify.asmx/CheckPhoneNumber?Phonenumber={uri.var.PhoneNumber}&LicenseKey={uri.var.LicenseKey}"/>


Here, you need to pass two parameters, which can be passed through the custom sequence. Edit the existing log-in message sequence like below and save;(you can create new sequence and save it)

<sequence xmlns="http://ws.apache.org/ns/synapse" name="log_in_message">

                <property name="uri.var.LicenseKey" value="0" scope="default" type="STRING"/>

                <property name="uri.var.PhoneNumber" expression="substring-after(get-property('To'),'/dimtry/1.0?PhoneNumber=')" scope="default" type="STRING"/>

</sequence>

If you check above sequence,  phonumber is extracted from incoming request using an xpath and hardcoded a value for licensekey, which user can modify according to his requirement.
Now when  we create and publish the api, select above insequence.

APIConfiguration:

Send a GET request for the API like;

http://localhost:8280/dimtry/1.0?PhoneNumber=+16506697051

You will get response;

Synapse Handler

Synapse handler is similar to axis2 handler , that can be used in RESTAPIs to handle incoming request and the responses.

Sample handler ;

package test;

import org.apache.synapse.MessageContext;

import org.apache.synapse.rest.AbstractHandler;

public class TestSynapseHandler extends AbstractHandler {

@Override

public boolean handleRequest(MessageContext messageContext) {

String idKey = "idKey";

String idValue = "abc";

messageContext.setProperty(idKey, idValue);

return true;

}

@Override

public boolean handleResponse(MessageContext messageContext) {

// TODO Response handling

return true;

}

}

Handler has to be registered in the RESTAPI configuration.

Sample configuration;

<api xmlns="http://ws.apache.org/ns/synapse" name="calAPI" context="/cal">
   <resource methods="GET">
      <nSequence>
         <send>
            <endpoint>
               <address uri="http://localhost:9763/services/calservice"/>
            </endpoint>
         </send>
      </inSequence>
      <outSequence>
         <send>
            <endpoint>
               <default/>
            </endpoint>
         </send>
      </outSequence>
   </resource>
<handlers>
        < handler class="test.TestSynapseHandler"/>
   </handlers>
</api>

REST Support in WSO2ESB - Handling JSON messages

In mobile applications we mostly use JSON messages, since they are easy to process. XML messages need more computational power to build the message.

 To process json messages, we need to enable the required message builder and formatter in the axis2 configuration.

 <messageFormatter  contentType="application/json" class="org.apache.axis2.json. JSONMessageFormatter"/>  

 <messageBuilder contentType="application/json"  class="org.apache.axis2.json. JSONBuilder"/>

Lets look at a sample scenario, where we need to 'GET' a json message from the backend service.
In this sample, we try to retrieve an user details which is stored in a database. To retrieve user details, we may define a simple "select" operation as a data-service.
Say, our data service runs at following endpoint;

http://localhost:9764/services/GetUserDetailsService.

As a second step,we need to define a suitable API for this..
Lets consider the "GET"  will be the only verb we are going to handle.

<api name="getusers" context="/public/user">
      <resource methods="GET"
                url-mapping="/*"
                inSequence="get-users-in-seq"
                faultSequence="fault"/>
   </api>

In the "get-users-in-seq" we might need to call our backend data service to retrieve user details.

 <sequence name="get-users-in-seq">  
      <property xmlns:ns="http://org.apache.synapse/xsd"
                name="userid"
                expression="substring-after(get-property('To'),'/public/user/')"/>
      <payloadFactory>
         <format>
           <p:getUserInfo xmlns:p="http://ws.wso2.org/dataservice">
               <p:Id>$1</p:Id>
            </p:getUserInfo>
        </format>
         <args>
            <arg xmlns:ns="http://org.apache.synapse/xsd"
                 expression="substring-after(get-property('To'),'/public/user/')"/>
         </args>
      </payloadFactory>
      <property name="SOAPAction" value="urn:getUserInfo" scope="transport"/>
      <send receive="recevingGetUserSeq">
         <endpoint>
            <address uri="http://localhost:9764/services/GetUserDetailsService"
                     format="soap11"/>
         </endpoint>
      </send>
   </sequence>

In the above sequence,

We construct the soap message using payloadfactory mediator, in a form which is expected by the backend data-service and send that to backend service. (note that, you can identify the SOAP message format, if you create a soapui project with the dataservice's wsdl.)

Backend service now will return the soap response, which we need to convert back as a json message and need to send back to the client.

   <sequence name="ecevingGetUserSeq">
         <xslt key="gov:/transformations/getUserTransform.xslt">
         <property xmlns:ns="http://org.apache.synapse/xsd"
                   name="userId"
                   expression="get-property('userid')"/>
      </xslt>
      <property name="messageType" value="application/json" scope="axis2"/>
      <send/>
   </sequence>

Here we use a XSLT script, which will formulate the expected json format which client expects.(ie: it will pick relevant info from the soap response and will construct a json message out of it)
Note that, we need to set the  "MessgeType"  property to "application/json", else axis2 wont pick the right message formatter.

We can execute this API with the following curl command to extract the user "Alice's" details.

   curl -v http://localhost:8280/public/user/Alice

Related post;
REST support in WSO2ESB - Introduction

REST support in WSO2ESB - Introduction

Version 4.0.3/later versions have an effective REST API mechanism to support REST invocations. The HTTP verbs such as GET/POST/PUT/DELETE..  can be handled with a simple configuration .

Sample REST API configuration to handle a GET request;

 <api name="echoAPI" context="/echo">
      <resource methods="GET"
                uri-template="/{string}"
                inSequence="echo-in-seq"
                outSequence="echo-out-seq"
                faultSequence="fault"/>
   </api> 

If you notice that ,here we define the context as "echo" which would be appear in the http url. User has to define a meaningful context if he wants to allow others  to use this API.
The url of the above API would be;
http://localhost:8280/echo
In this API we restricted ESB to handle only the GET requests. So, if user sends  requests for other verbs, those will be dropped at ESB end.

For the ur-template, we get only single parameter from the enduser.
So, to invoke this API, user has to send a single query parameter.
http://localhost:8280/echo?testString

If user sends multiple query parameters he has to define something like;
uri-template="/{string1}/{string2}"
uri-template="/{string1}&{string2}"
But it totally depends on the service implementation, how user going to handle the template.

If we have number of query parameters we could simply define the url-mapping like;

url-mapping="/*"

This will accept all the GET requests coming with the following URL format;
http://localhost:8280/echo


Related post ;
REST Support in WSO2ESB - Handling JSON messages

Invoking a RESTful service via WSO2ESB

In the ESB, when we define a proxy, it is not a must to provide the service wsdl, unless if you want to hide/add a new elements in your service contract.
Lets check a  very simple basic proxy to process a HTTP GET request

• Get wso2esb binary distribution.
• Deploy the simplestockquote service and start the sample axis2server.
• Start ESB.

Create the following proxy;

<proxy name="RestProxy" transports="https http" startOnLoad="true" trace="disable">         <target>               <endpoint>               <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>             </endpoint>                          <outSequence>                 <send/>             </outSequence>         </target>     </proxy>

Execute the following GETrequest url in your browser;
http://localhost:8280/services/RestProxy/getSimpleQuote?symbol=IBM

Now you will see the response in your browser. If you place the tcpmon between client and ESB, you can check your http 'get' request,

GET /services/RestProxy/getSimpleQuote?symbol=IBM HTTP/1.1

Host: 127.0.0.1:5555

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.24) Gecko/20111103 Firefox/3.6.24

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Language: en-us,en;q=0.5

Accept-Encoding: gzip,deflate

Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7

Keep-Alive: 115

Connection: keep-alive

Cookie: region1_configure_menu=; region3_registry_menu=visible; region4_monitor_menu=;

In the above sample client sends the 'symbol=IBM' as the parameter for the operation "getSimpleQuote"..Say in the mediation logic user may need to change the parameter as 'SUN'.(ie:symbol=SUN)..For that he/she can use "REST_URL_POSTFIX" property ..Which basically adds the suffix for the REST service endpoint.
eg:
   <property name="REST_URL_POSTFIX" value="/getSimpleQuote?symbol=SUN" scope="axis2"/>

So, the insequence would be;

    <inSequence>

                <property name="REST_URL_POSTFIX" value="/getSimpleQuote?symbol=SUN" scope="axis2"/>

                <send>

                    <endpoint>

                        <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>

                    </endpoint>

                </send>

    </inSequence>

User could add your own mediation logic with whatever the mediators within the sequence..

Related post;
REST support in WSO2ESB - Introduction
REST Support in WSO2ESB - Handling JSON messages