Добавлен модуль downloader

Author: aNNiMON

build.gradle

@@ -79,7 +79,8 @@ task sandbox(dependsOn: proguard, type: Jar) {
     exclude "**/modules/canvas/**", "**/modules/canvasfx/**", "**/modules/forms/**",
             "**/modules/java/**", "**/modules/jdbc/**", "**/modules/robot/**",
             "**/modules/socket/**", "io/**",
-            "**/modules/aimp/**", "aimpremote/**"
+            "**/modules/aimp/**", "aimpremote/**",
+            "**/modules/downloader/**"
 
     manifest {
         attributes 'Main-Class': project.mainClass

src/main/java/com/annimon/ownlang/modules/downloader/downloader.java

@@ -0,0 +1,98 @@
+package com.annimon.ownlang.modules.downloader;
+
+import com.annimon.ownlang.Console;
+import com.annimon.ownlang.lib.Arguments;
+import com.annimon.ownlang.lib.Function;
+import com.annimon.ownlang.lib.FunctionValue;
+import com.annimon.ownlang.lib.Functions;
+import com.annimon.ownlang.lib.NumberValue;
+import com.annimon.ownlang.lib.Types;
+import com.annimon.ownlang.lib.Value;
+import com.annimon.ownlang.modules.Module;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public final class downloader implements Module {
+
+    @Override
+    public void init() {
+        Functions.set("getContentLength", this::getContentLength);
+        Functions.set("downloader", this::downloader);
+    }
+
+    private Value getContentLength(Value... args) {
+        Arguments.check(1, args.length);
+        return NumberValue.of(getContentLength(args[0].asString()));
+    }
+
+    private Value downloader(Value... args) {
+        Arguments.checkRange(2, 4, args.length);
+        final String downloadUrl = args[0].asString();
+        final String filePath = args[1].asString();
+        final Function progressCallback;
+        final int contentLength;
+        if ( (args.length >= 3) && (args[2].type() == Types.FUNCTION) ) {
+            progressCallback = ((FunctionValue) args[2]).getValue();
+            // For showing progress we need to get content length
+            contentLength = getContentLength(downloadUrl);
+        } else {
+            progressCallback = null;
+            contentLength = -1;
+        }
+        final int bufferSize = (args.length == 4) ? Math.max(1024, args[3].asInt()) : 16384;
+
+        final NumberValue contentLengthBoxed = NumberValue.of(contentLength);
+        final boolean calculateProgressEnabled = contentLength > 0 && progressCallback != null;
+        if (calculateProgressEnabled) {
+            progressCallback.execute(
+                    NumberValue.ZERO /*%*/,
+                    NumberValue.ZERO /*bytes downloaded*/,
+                    contentLengthBoxed /*file size*/);
+        }
+
+        try (InputStream is = new URL(downloadUrl).openStream();
+             OutputStream os = new FileOutputStream(Console.fileInstance(filePath))) {
+            int downloaded = 0;
+            final byte[] buffer = new byte[bufferSize];
+            int readed;
+            while ((readed = is.read(buffer, 0, bufferSize)) != -1) {
+                os.write(buffer, 0, readed);
+                downloaded += readed;
+                if (calculateProgressEnabled) {
+                    final int percent = downloaded * 100 / contentLength;
+                    progressCallback.execute(
+                            NumberValue.of(percent),
+                            NumberValue.of(downloaded),
+                            contentLengthBoxed);
+                }
+            }
+        } catch (IOException ioe) {
+            return NumberValue.ZERO;
+        } finally {
+            if (progressCallback != null) {
+                progressCallback.execute(NumberValue.of(100), contentLengthBoxed, contentLengthBoxed);
+            }
+        }
+        return NumberValue.ONE;
+    }
+
+    private static int getContentLength(String url) {
+        HttpURLConnection connection = null;
+        try {
+            connection = (HttpURLConnection) new URL(url).openConnection();
+            connection.setRequestMethod("HEAD");
+            connection.connect();
+            return connection.getContentLength();
+        } catch (IOException ioe) {
+            return -1;
+        } finally {
+            if (connection != null) {
+                connection.disconnect();
+            }
+        }
+    }
+}