Sparkjava

How to create a executable jar containing a jetty based REST resource in 10 mins.

Create an app

1. Install sdkman with curl -s "https://get.sdkman.io" | bash
2. Install gradle with sdk install gradle
3. Create an app folder

mkdir app
cd app

4. Init a gradle java application gradle init --type java-application
5. Build the app ./gradlew buid
6. Run the app ./gradlew run

Create rest resource with sparkjava

1. Add the sparkjava dependency compile "com.sparkjava:spark-core:2.5.5"
2. Create a basic app in src/main/java/App.java

public class App {
    public static void main(String[] args) {
        path("/api", () -> {
            get("/hello-world", (req, res) -> {
            });
        });
    }
}

3. Test it by running ./gradlew run and open browser on http://localhost:4567/api/hello-world

Create a executable jar

1. Add the shadow gradle plugin https://github.com/johnrengelman/shadow
2. Build the app ./gradlew buid
3. Run the jar java -jar build/libs/<appnam>-all.jar
4. Test it by opening a browser on http://localhost:4567/api/hello-world

To generate a soap client

1. Download apache cxf curl http://www-eu.apache.org/dist/cxf/3.1.10/apache-cxf-3.1.10.zip
2. Extract the wsdl2java binary and add it to your path
3. Generate the java code from wsdl2java -client http://www.webservicex.com/globalweather.asmx?WSDL
4. Include the generated code in your project and call the web service e.g.

GlobalWeather ss = new GlobalWeather();
GlobalWeatherSoap port = ss.getGlobalWeatherSoap12();  
return port.getCitiesByCountry("Norway");

Useful gradle commands

./gradlew -h
./gradlew tasks
./gradlew build
./gradlew run

Improvements

1. Download the wsdl and generate a soap client with gradle e.g. https://github.com/nilsmagnus/wsdl2java
2. Add validation
3. Add environment properties
4. Add service scripts