Home work 10

org/geekhub/ConnectionUtils.java

@@ -1,6 +1,9 @@
 package org.geekhub;
 
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.URL;
 
 /**
@@ -16,7 +19,16 @@ public class ConnectionUtils {
      * @throws IOException
      */
     public static byte[] getData(URL url) throws IOException {
-        //implement me
-        return null;
+        InputStream in = new BufferedInputStream(url.openStream());
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        int len = 0;
+        byte[] bytes = new byte[1024];
+        while (-1!=(len=in.read(bytes))){
+            out.write(bytes,0,len);
+        }
+        in.close();
+        out.close();
+
+        return out.toByteArray();
     }
 }

org/geekhub/ImageCrawler.java

@@ -1,8 +1,11 @@
 package org.geekhub;
 
-import java.io.*;
+import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
@@ -29,7 +32,12 @@ public ImageCrawler(String folder) throws MalformedURLException {
      * @throws IOException
      */
     public void downloadImages(String urlToPage) throws IOException {
-        //implement me
+        Page page = new Page(new URL(urlToPage));
+        Collection<URL> imageLinks = page.getImageLinks();
+
+        imageLinks.stream()
+                .filter(imageLink -> isImageURL(imageLink))
+                .forEach(imageLink -> executorService.execute(new ImageTask(imageLink,folder)));
     }
 
     /**
@@ -41,10 +49,18 @@ public void stop() {
 
     //detects is current url is an image. Checking for popular extensions should be enough
     private boolean isImageURL(URL url) {
-        //implement me
-        return false;
-    }
+        List<String> imageExtensions = Arrays.asList("jpg","jpeg","gif","png");
+        String imageExtension = getExtension(url).toLowerCase();
 
+        return imageExtensions.contains(imageExtension);
+    }
 
+    private String getExtension(URL url) {
+        String extension = "";
+        String urlString = url.toString();
+        int posDot = urlString.lastIndexOf(".");
+        if (posDot > 0) extension = urlString.substring(posDot + 1);
+        return extension;
+    }
 
 }

org/geekhub/ImageTask.java

@@ -1,5 +1,9 @@
 package org.geekhub;
 
+import java.io.BufferedOutputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
 import java.net.URL;
 
 /**
@@ -20,7 +24,22 @@ public ImageTask(URL url, String folder) {
      */
     @Override
     public void run() {
-       //implement me
+        OutputStream image = null;
+        try {
+            byte[] imageBytes = ConnectionUtils.getData(url);
+            String imagePath = folder + "\\" + buildFileName(url);
+            image = new BufferedOutputStream(new FileOutputStream(imagePath));
+            image.write(imageBytes);
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            if (image!=null) try {
+                image.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
     }
 
     //converts URL to unique file name