How to fetch HTTP parameters in java transformer in MULE ESB

Question

I am bit new at Mule ESB and Anypoint Studio so I am trying to figure out how to fetch HTTP query parameters in a java transformer class.

I have tried

String firstname = message.getInboundProperty("fname");
String lastName = message.getInboundProperty("lname");

even went with

Map<String, String> queryParams = message.getInboundProperty("http.query.params");
String firstname = queryParams.get("fname");
String lastname = queryParams.get("lname");

but they return null values, I have even tried to use Callable Interface but I think it only possible to use it if it's a JAVA Component.

Do please let me know,

Thanks.

Answer 1

If you want to use in a Java transformer, you can follow the following example :-

public class MyCustomTransformer extends AbstractMessageTransformer {
 @Override
 public Object transformMessage(MuleMessage message, String outputEncoding) throws TransformerException {

     Map<String, String> queryParams = message.getInboundProperty("http.query.params");
     String fname=queryParams.get("fname");
     System.out.println("fname: "+fname);
     String lname=queryParams.get("lname");
     System.out.println("lname: "+lname);
     return message;

 }
} 

And Mule flow will be :-

 <http:listener-config name="HTTP_Listener_Configuration" host="0.0.0.0" port="8081" doc:name="HTTP Listener Configuration"/>

 <flow name="Testlow">
   <http:listener config-ref="HTTP_Listener_Configuration" path="/test" doc:name="HTTP"/>
  <custom-transformer class="MyCustomTransformer" doc:name="Java"/>
 </flow>

Now if you hit the url with query parameter for example:- http://localhost:8081/test?fname=anirban&lname=sen

You will get the following result in your console:-

Answer 2

You could also get property as a separate approach below.

public class MyCustomTransformer extends AbstractMessageTransformer { @Override public Object transformMessage(MuleMessage message, String outputEncoding) throws TransformerException {

        Map<String, String> queryParams = 
        message.getProperty("http.query.params", PropertyScope.INVOCATION);
        String fname=queryParams.get("fname");
        System.out.println("fname: "+fname);
        String lname=queryParams.get("lname");
        System.out.println("lname: "+lname);
        return message;

     }
     }