just showing my refactoring

build.gradle

@@ -10,6 +10,7 @@ targetCompatibility = 1.8
 
 repositories {
     mavenCentral()
+    jcenter()
 }
 
 dependencies {
@@ -20,6 +21,12 @@ dependencies {
     compile 'ch.qos.logback:logback-classic:1.0.1'
     compile 'ch.qos.logback:logback-core:1.0.1'
 
+    compile 'com.github.florent37:retrojsoup:1.0.3'
+    compile 'com.github.florent37:rxjsoup:1.0.3'
+    compile 'org.jsoup:jsoup:1.10.2'
+    compile 'io.reactivex.rxjava2:rxjava:2.0.8'
+    compileOnly 'com.github.florent37:retrojsoup-compiler:1.0.3'
+
     compileOnly "org.projectlombok:lombok:1.16.10"
 
     testCompile 'org.spockframework:spock-core:1.0-groovy-2.4'

src/main/java/com/softwaremill/java_fp_example/contest/maciejdobrowolski/FacebookImage.java

@@ -0,0 +1,59 @@
+package com.softwaremill.java_fp_example.contest.maciejdobrowolski;
+
+import static com.softwaremill.java_fp_example.DefaultImage.DEFAULT_IMAGE;
+import static io.reactivex.schedulers.Schedulers.io;
+import static java.util.concurrent.TimeUnit.SECONDS;
+
+import com.github.florent37.retrojsoup.RetroJsoup;
+import io.reactivex.Maybe;
+import io.reactivex.ObservableTransformer;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class FacebookImage {
+
+    private final static String FACEBOOK_IMAGE_TAG = "og:image";
+    private final static MetaEntry FALLBACK_META_ENTRY = new MetaEntry(FACEBOOK_IMAGE_TAG, DEFAULT_IMAGE);
+    private final static int TIMEOUT_IN_SECONDS = 10;
+
+    private final String url;
+
+    public FacebookImage(String url) {
+        this.url = url;
+    }
+
+    public Maybe<String> imageAddress() {
+        return pageModel().metaTags()
+                .subscribeOn(io())
+                .compose(defaultOnTimeout())
+                .filter(FacebookImage::isFacebookImageTag)
+                .compose(firstOrDefault())
+                .singleElement()
+                .map(meta -> meta.content);
+    }
+
+    private PageModel pageModel() {
+        return new RetroJsoup.Builder()
+                .url(url)
+                .build()
+                .create(PageModel.class);
+    }
+
+    private ObservableTransformer<MetaEntry, MetaEntry> defaultOnTimeout() {
+        return upstream -> upstream.timeout(TIMEOUT_IN_SECONDS, SECONDS)
+                .doOnError(e -> log.error("Unable to extract og:image from url {}. Problem: {}", url, e.getMessage()))
+                .onErrorReturnItem(FALLBACK_META_ENTRY);
+    }
+
+    private static boolean isFacebookImageTag(MetaEntry metaEntry) {
+        return FACEBOOK_IMAGE_TAG.equals(metaEntry.attr);
+    }
+
+    private ObservableTransformer<MetaEntry, MetaEntry> firstOrDefault() {
+        return upstream -> upstream.firstOrError()
+                .doOnError(e -> log.warn("No {} found for blog post {}", FACEBOOK_IMAGE_TAG, url))
+                .onErrorReturnItem(FALLBACK_META_ENTRY)
+                .toObservable();
+    }
+
+}

src/main/java/com/softwaremill/java_fp_example/contest/maciejdobrowolski/LICENSE.txt

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 MaciejDobrowolski
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

src/main/java/com/softwaremill/java_fp_example/contest/maciejdobrowolski/MetaEntry.java

@@ -0,0 +1,20 @@
+package com.softwaremill.java_fp_example.contest.maciejdobrowolski;
+
+import com.github.florent37.retrojsoup.annotations.JsoupAttr;
+
+class MetaEntry {
+
+    @JsoupAttr(value = "meta", attr = "property")
+    String attr;
+
+    @JsoupAttr(value = "meta", attr = "content")
+    String content;
+
+    MetaEntry() {
+    }
+
+    MetaEntry(String attr, String content) {
+        this.attr = attr;
+        this.content = content;
+    }
+}

src/main/java/com/softwaremill/java_fp_example/contest/maciejdobrowolski/PageModel.java

@@ -0,0 +1,11 @@
+package com.softwaremill.java_fp_example.contest.maciejdobrowolski;
+
+import com.github.florent37.retrojsoup.annotations.Select;
+import io.reactivex.Observable;
+
+interface PageModel {
+
+    @Select("head meta")
+    Observable<MetaEntry> metaTags();
+
+}

src/test/groovy/com/softwaremill/java_fp_example/contest/maciejdobrowolski/FacebookImageSpec.groovy

@@ -0,0 +1,26 @@
+package com.softwaremill.java_fp_example.contest.maciejdobrowolski
+
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import static com.softwaremill.java_fp_example.DefaultImage.DEFAULT_IMAGE
+
+class FacebookImageSpec extends Specification {
+
+    @Unroll
+    def "should test Maciej's version with address #postAddress"() {
+        when:
+            FacebookImage facebookImage = new FacebookImage(postAddress)
+
+        then:
+            facebookImage.imageAddress().blockingGet() == expectedImageUrl
+
+        where:
+            postAddress                                                || expectedImageUrl
+            "https://softwaremill.com/the-wrong-abstraction-recap/"    || "https://softwaremill.com/images/uploads/2017/02/street-shoe-chewing-gum.0526d557.jpg"
+            "https://softwaremill.com/using-kafka-as-a-message-queue/" || "https://softwaremill.com/images/uploads/2017/02/kmq.93f842cf.png"
+            "https://twitter.com/softwaremill"                         || DEFAULT_IMAGE
+            "http://i-do-not-exist.pl"                                 || DEFAULT_IMAGE
+    }
+
+}