JarCastingAuto Spark
Auto Spark is an alternative way to use Spark. This example assumes you have a basic understanding of how to use Spark.
###Downloads
Maven
<dependency>
<groupId>com.alta189</groupId>
<artifactId>auto-spark</artifactId>
<version>1.1</version>
</dependency>
Gradle
'com.alta189:auto-spark:1.1'
You can also download the jars here.
###Getting Started
ExampleServer.java
import com.alta189.auto.spark.AutoSpark;
public class ExampleServer {
public static void main(String[] args) {
new AutoSpark().run();
}
}
HelloWorld.java
import com.alta189.auto.spark.Controller;
import com.alta189.auto.spark.ResourceMapping;
import spark.Request;
import spark.Response;
@Controller
public class HelloWorld {
@ResourceMapping("/hello")
public String hello(Request request, Response response) {
return "Hello, World!";
}
}
View at: http://localhost:4567/hello
###Examples
ExampleController.java
import com.alta189.auto.spark.Controller;
import com.alta189.auto.spark.RequestMethod;
import com.alta189.auto.spark.ResourceMapping;
import spark.Request;
import spark.Response;
@Controller
public class ExampleController {
@ResourceMapping(value = "/users/add", method = RequestMethod.PUT)
public String addUser(Request request, Response response) {
// Internal Logic
}
@ResourceMapping(value = "/users/update", method = RequestMethod.POST)
public String updateUser(Request request, Response response) {
// Internal Logic
}
@ResourceMapping(value = "/users/delete", method = RequestMethod.DELETE)
public String deleteUser(Request request, Response response) {
// Internal Logic
}
@ResourceMapping(value = "/users/list", method = RequestMethod.GET)
public String listUsers(Request request, Response response) {
// Internal Logic
}
}
You could also simplify each methods @ResourceMapping by removing the /users from each and adding @ResourceMapping("/users") to the class.
Result.java
import com.alta189.auto.spark.AutoSparkUtils;
import com.alta189.auto.spark.SparkResponseTransformer;
public class Result {
private final String result;
public Result(String result) {
this.result = result;
}
public String getResult() {
return "{ \"result\" : \"" + result + "\" }";
}
public static class ResultTransformer extends SparkResponseTransformer {
@Override
public String render(Object model) throws Exception {
Result result = AutoSparkUtils.safeCast(model);
if (result == null) {
throw new IllegalAccessException("result null");
}
return result.getResult();
}
}
}
TransformerExample.java
import com.alta189.auto.spark.Controller;
import com.alta189.auto.spark.ResourceMapping;
import com.alta189.auto.spark.Transformer;
import spark.Request;
import spark.Response;
@Controller
public class TransformerExample {
@Transformer(Result.ResultTransformer.class)
@ResourceMapping("/status")
public Result status(Request request, Response response) {
return new Result("online");
}
@Transformer(Result.ResultTransformer.class)
@ResourceMapping("/health")
public Result health(Request request, Response response) {
return new Result("good");
}
@ResourceMapping("/hello")
public String hello(Request request, Response response) {
return "Hello, World!";
}
}
You can simplify this class by declaring the Transformer to be for the entire class and setting the /hello resource to ignore the parent transformer as seen below
import com.alta189.auto.spark.Controller;
import com.alta189.auto.spark.ResourceMapping;
import com.alta189.auto.spark.Transformer;
import spark.Request;
import spark.Response;
@Controller
@Transformer(Result.ResultTransformer.class)
public class TransformerExample {
@ResourceMapping("/status")
public Result status(Request request, Response response) {
return new Result("online");
}
@ResourceMapping("/health")
public Result health(Request request, Response response) {
return new Result("good");
}
@Transformer(ignoreParent = true)
@ResourceMapping("/hello")
public String hello(Request request, Response response) {
return "Hello, World!";
}
}
hello.ftl
<h1>Hello, ${message}!</h1>
TemplateEngineExample.java
import com.alta189.auto.spark.ResourceMapping;
import com.alta189.auto.spark.TemplateEngine;
import spark.ModelAndView;
import spark.Request;
import spark.Response;
import spark.utils.StringUtils;
import java.util.HashMap;
import java.util.Map;
public class TemplateEngineExample {
@ResourceMapping("/hello/:message")
@TemplateEngine(FreeMarkerEngine.class)
public ModelAndView template(Request request, Response response) {
Map<String, Object> attributes = new HashMap<>();
String message = request.params("message");
if (StringUtils.isEmpty(message)) {
message = "World";
}
attributes.put("message", message);
return new ModelAndView(attributes, "hello.ftl");
}
}
Just like @Transformer a template engine can be set at the class level and then ignored at the method level.
ExceptionExample.java
import com.alta189.auto.spark.Controller;
import com.alta189.auto.spark.ExceptionMapping;
import spark.Request;
import spark.Response;
@Controller
public class ExceptionExample {
@ExceptionMapping(NotFoundException.class)
public void notFound(Request request, Response response) {
response.status(404);
response.body("Resource not found");
}
@ExceptionMapping(NullPointerException.class)
public void notFound(Request request, Response response) {
response.status(404);
response.body("Oops! Looks like something was broken!");
}
}
FilterExample.java
import com.alta189.auto.spark.SparkFilter;
import spark.Request;
import spark.Response;
public class FilterExample extends SparkFilter {
@Override
public void before(Request request, Response response) {
// Before the Request is handled
}
@Override
public void after(Request request, Response response) {
// After the Request is handled
}
}
Adding @FilterMapping("/api/*") to the Class would limit the filter to only paths starting with /api/.