BAEL-2982 NanoHTTPD guide (#7148)

libraries-server/pom.xml

@@ -96,6 +96,19 @@
              <artifactId>smack-java7</artifactId>
              <version>${smack.version}</version>
          </dependency>
+
+        <!-- NanoHTTPD -->
+        <dependency>
+            <groupId>org.nanohttpd</groupId>
+            <artifactId>nanohttpd</artifactId>
+            <version>${nanohttpd.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.nanohttpd</groupId>
+            <artifactId>nanohttpd-nanolets</artifactId>
+            <version>${nanohttpd.version}</version>
+        </dependency>
+
     </dependencies>
 
     <properties>
@@ -108,6 +121,7 @@
         <tomcat.version>8.5.24</tomcat.version>
         <smack.version>4.3.1</smack.version>
 		<eclipse.paho.client.mqttv3.version>1.2.0</eclipse.paho.client.mqttv3.version>
+		<nanohttpd.version>2.3.1</nanohttpd.version>
     </properties>
 
 </project>

libraries-server/src/main/java/com/baeldung/nanohttpd/ApplicationController.java

@@ -0,0 +1,38 @@
+package com.baeldung.nanohttpd;
+
+import fi.iki.elonen.NanoHTTPD;
+import fi.iki.elonen.router.RouterNanoHTTPD;
+
+import java.io.IOException;
+
+public class ApplicationController extends RouterNanoHTTPD {
+
+    ApplicationController() throws IOException {
+        super(8072);
+        addMappings();
+        start(NanoHTTPD.SOCKET_READ_TIMEOUT, false);
+    }
+
+    @Override
+    public void addMappings() {
+        addRoute("/", IndexHandler.class);
+        addRoute("/users", UserHandler.class);
+    }
+
+    public static class UserHandler extends DefaultHandler {
+        @Override
+        public String getText() {
+            return "UserA, UserB, UserC";
+        }
+
+        @Override
+        public String getMimeType() {
+            return MIME_PLAINTEXT;
+        }
+
+        @Override
+        public Response.IStatus getStatus() {
+            return Response.Status.OK;
+        }
+    }
+}

libraries-server/src/main/java/com/baeldung/nanohttpd/ItemGetController.java

@@ -0,0 +1,22 @@
+package com.baeldung.nanohttpd;
+
+import fi.iki.elonen.NanoHTTPD;
+
+import java.io.IOException;
+
+public class ItemGetController extends NanoHTTPD {
+
+    ItemGetController() throws IOException {
+        super(8071);
+        start(NanoHTTPD.SOCKET_READ_TIMEOUT, false);
+    }
+
+    @Override
+    public Response serve(IHTTPSession session) {
+        if (session.getMethod() == Method.GET) {
+            String itemIdRequestParam = session.getParameters().get("itemId").get(0);
+            return newFixedLengthResponse("Requested itemId = " + itemIdRequestParam);
+        }
+        return newFixedLengthResponse(Response.Status.NOT_FOUND, MIME_PLAINTEXT, "The requested resource does not exist");
+    }
+}

libraries-server/src/test/java/com/baeldung/nanohttpd/ApplicationControllerUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.nanohttpd;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.HttpClient;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.junit.Assert.*;
+
+public class ApplicationControllerUnitTest {
+
+    private static final String BASE_URL = "http://localhost:8072/";
+    private static final HttpClient CLIENT = HttpClientBuilder.create().build();
+
+    @BeforeClass
+    public static void setUp() throws IOException {
+        new ApplicationController();
+    }
+
+    @Test
+    public void givenServer_whenRootRouteRequested_thenHelloWorldReturned() throws IOException {
+        HttpResponse response = CLIENT.execute(new HttpGet(BASE_URL));
+        assertTrue(IOUtils.toString(response.getEntity().getContent()).contains("Hello world!"));
+        assertEquals(200, response.getStatusLine().getStatusCode());
+    }
+
+    @Test
+    public void givenServer_whenUsersRequested_thenThenAllUsersReturned() throws IOException {
+        HttpResponse response = CLIENT.execute(new HttpGet(BASE_URL + "users"));
+        assertEquals("UserA, UserB, UserC", IOUtils.toString(response.getEntity().getContent()));
+    }
+}

libraries-server/src/test/java/com/baeldung/nanohttpd/ItemGetControllerUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.nanohttpd;
+
+import static org.junit.Assert.*;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.HttpClient;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.IOException;
+
+public class ItemGetControllerUnitTest {
+
+    private static final String URL = "http://localhost:8071";
+    private static final HttpClient CLIENT = HttpClientBuilder.create().build();
+
+    @BeforeClass
+    public static void setUp() throws IOException {
+        new ItemGetController();
+    }
+
+    @Test
+    public void givenServer_whenDoingGet_thenParamIsReadCorrectly() throws IOException {
+        HttpResponse response = CLIENT.execute(new HttpGet(URL + "?itemId=1234"));
+        assertEquals("Requested itemId = 1234", IOUtils.toString(response.getEntity().getContent()));
+    }
+
+    @Test
+    public void givenServer_whenDoingPost_then404IsReturned() throws IOException {
+        HttpResponse response = CLIENT.execute(new HttpPost(URL));
+        assertEquals(404, response.getStatusLine().getStatusCode());
+    }
+}