diff --git a/app/src/main/java/net/kdt/pojavlaunch/util/DownloadUtils.java b/app/src/main/java/net/kdt/pojavlaunch/util/DownloadUtils.java
index 37f2e90419..144832d548 100644
--- a/app/src/main/java/net/kdt/pojavlaunch/util/DownloadUtils.java
+++ b/app/src/main/java/net/kdt/pojavlaunch/util/DownloadUtils.java
@@ -5,6 +5,7 @@
 import java.net.*;
 import java.nio.charset.*;
 import net.kdt.pojavlaunch.*;
+import org.apache.commons.io.*;
 
 public class DownloadUtils {
     public static final String USER_AGENT = Tools.APP_NAME;
@@ -20,7 +21,6 @@ public static void download(String url, OutputStream os) {
 
     public static void download(URL url, OutputStream os) throws Throwable {
         InputStream is = null;
-        byte[] buf; // 16384
         try {
 			// System.out.println("Connecting: " + url.toString());
             HttpURLConnection conn = (HttpURLConnection) url.openConnection();
@@ -32,9 +32,8 @@ public static void download(URL url, OutputStream os) throws Throwable {
                 throw new RuntimeException("Server returned HTTP " + conn.getResponseCode()
 					+ ": " + conn.getResponseMessage());
             }
-			buf = new byte[conn.getContentLength()];
             is = conn.getInputStream();
-            IoUtil.pipe(is, os, buf);
+			IOUtils.copy(is, os);
         } finally {
 			if (is != null) {
                 try {
diff --git a/app/src/main/java/net/kdt/pojavlaunch/util/IoUtil.java b/app/src/main/java/net/kdt/pojavlaunch/util/IoUtil.java
deleted file mode 100644
index 33d1c2a488..0000000000
--- a/app/src/main/java/net/kdt/pojavlaunch/util/IoUtil.java
+++ /dev/null
@@ -1,107 +0,0 @@
-package net.kdt.pojavlaunch.util;
-
-import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.Enumeration;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipFile;
-import java.util.zip.ZipOutputStream;
-import net.kdt.pojavlaunch.*;
-import android.os.*;
-
-public class IoUtil {
-	
-	//public static volatile boolean cancel = false;
-	
-    private IoUtil() {
-    }
-
-    public static void pipe( /*PojavLauncherActivity activity,*/ InputStream is, OutputStream out, byte[] buf) throws IOException {
-        while (true) {
-			//if (cancel) throw new CancelException();
-			
-            int amt = is.read(buf);
-            if (amt >= 0) {
-                out.write(buf, 0, amt);
-            } else {
-                return;
-            }
-        }
-    }
-
-    public static void copy(File from, File to, byte[] buf) throws IOException {
-        InputStream in = new FileInputStream(from);
-        OutputStream out;
-        try {
-            out = new FileOutputStream(to);
-            pipe(in, out, buf);
-            out.close();
-            in.close();
-        } catch (Throwable th) {
-            in.close();
-        }
-    }
-
-    public static void copyZipWithoutEmptyDirectories(File inputFile, File outputFile) throws IOException {
-        byte[] buf = new byte[8192];
-        ZipFile inputZip = new ZipFile(inputFile);
-        ZipOutputStream outputStream = new ZipOutputStream(new FileOutputStream(outputFile));
-        try {
-            Enumeration<? extends ZipEntry> e = inputZip.entries();
-            ArrayList<ZipEntry> sortedList = new ArrayList();
-            while (e.hasMoreElements()) {
-                sortedList.add((ZipEntry) e.nextElement());
-            }
-            Collections.sort(sortedList, new Comparator<ZipEntry>() {
-                public int compare(ZipEntry o1, ZipEntry o2) {
-                    return o1.getName().compareTo(o2.getName());
-                }
-            });
-            for (int i = sortedList.size() - 1; i >= 0; i--) {
-                boolean isEmptyDirectory;
-                ZipEntry inputEntry = (ZipEntry) sortedList.get(i);
-                String name = inputEntry.getName();
-                if (!inputEntry.isDirectory()) {
-                    isEmptyDirectory = false;
-                } else if (i == sortedList.size() - 1) {
-                    isEmptyDirectory = true;
-                } else {
-                    isEmptyDirectory = !((ZipEntry) sortedList.get(i + 1)).getName().startsWith(name);
-                }
-                if (isEmptyDirectory) {
-                    sortedList.remove(inputEntry);
-                } else {
-                    outputStream.putNextEntry(new ZipEntry(inputEntry));
-                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                    InputStream is = inputZip.getInputStream(inputEntry);
-                    pipe(is, baos, buf);
-                    is.close();
-                    outputStream.write(baos.toByteArray());
-                }
-            }
-        } finally {
-            outputStream.close();
-        }
-    }
-
-    public static void clearDirectory(File dir) {
-        File[] fileList = dir.listFiles();
-        if (fileList != null) {
-            for (File f : fileList) {
-                if (f.isDirectory()) {
-                    clearDirectory(f);
-                }
-                f.delete();
-            }
-        }
-    }
-}
-