Hello World Backend

Lembas Hello World example

If you followed the steps and generated the source code, you notice that it only contains endpoint address and a base class. You need artifacts and enpoints to be able to generate code and make request to your backend.

Endpoints

Create a package in your project com.happyblueduck.enpoints and add your first endpoint by extending LembasRequest...

Java

package com.happyblueduck.enpoints;

import com.happyblueduck.lembas.core.LembasResponse;
import com.happyblueduck.lembas.core.UtilSerializeException;
import com.happyblueduck.lembas.processing.LembasActionContext;
import com.happyblueduck.lembas.processing.LembasProcessRequest;
import com.happyblueduck.lembas.processing.RequestProcessException;

public String requestParamString;
public int requestParamInt; 
public double requestParamDouble;  

public class HelloWorldRequest extends LembasProcessRequest {
	@Override
	public LembasResponse process(LembasActionContext lembasActionContext) throws RequestProcessException, UtilSerializeException {
		HelloWorldResponse response = new HelloWorldResponse(); 					
    response.message = "Goodbye, cruel world";
		return response; 
		}
}

...and LembasResponse

Java

package com.happyblueduck.enpoints;

import com.happyblueduck.lembas.core.LembasResponse;

public class HelloWorldResponse extends LembasResponse {
        public String message; 
}

Artifacts

We can also add an artifact to our backend. Create a package named com.happyblueduck.artifact and add an artifact by extending LembasObject:

Java

package com.happyblueduck.artifacts;

import com.happyblueduck.lembas.core.LembasObject
import java.util.Date;
import java.util.ArrayList; 

public class HelloArtifact extends LembasObject{

        // lembas supports primiteves
        public String sstring; 
        public Double ddouble; 
        public Long   llong; 
        public Date ddate;

        // and arrays
        public ArrayList<String> aarray; 

        // and array of lembasObjects
        public ArrayList<HelloArtifact> artifacst; 

}

Now that we have our first endpoint, we should update our Configuration:

Java

@Override
    public void init() throws ServletException {
        //service name and servlet url-mapping should match
        Config.serviceName  = "Arwen"; 
        Config.version      = "1.0";
        Config.HOST_URL     = http://localhost";
        Config.HOST_PORT    = "8080"

        // endpoints and artifacts are added by packages
        Config.addEndpoint("com.happyblueduck.enpoints"); 
    }

If you generate the iOS source code now from http://localhost:8080/lembas?target=objc, you will see HelloRequest, HelloResponse and HelloArtifact classes. You can now build an iOS application that use this service with Lembas-ios.