Add[FileUtils]: zip decompression

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/utils/FileUtils.java

@@ -1,9 +1,57 @@
 package net.kdt.pojavlaunch.utils;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
 
 public class FileUtils {
     public static boolean exists(String filePath){
         return new File(filePath).exists();
     }
+
+    public static void uncompressZip(File filePath, File output) throws IOException {
+        final byte[] buffer = new byte[8192];
+        final ZipInputStream zis = new ZipInputStream(new FileInputStream(filePath));
+        ZipEntry zipEntry = zis.getNextEntry();
+        while (zipEntry != null) {
+            final File newFile = newFile(output, zipEntry);
+            if (zipEntry.isDirectory()) {
+                if (!newFile.isDirectory() && !newFile.mkdirs()) {
+                    throw new IOException("Failed to create directory " + newFile);
+                }
+            } else {
+                File parent = newFile.getParentFile();
+                if (!parent.isDirectory() && !parent.mkdirs()) {
+                    throw new IOException("Failed to create directory " + parent);
+                }
+
+                final FileOutputStream fos = new FileOutputStream(newFile);
+                int len;
+                while ((len = zis.read(buffer)) > 0) {
+                    fos.write(buffer, 0, len);
+                }
+                fos.close();
+            }
+            zipEntry = zis.getNextEntry();
+        }
+        zis.closeEntry();
+        zis.close();
+    }
+
+    public static File newFile(File destinationDir, ZipEntry zipEntry) throws IOException {
+        File destFile = new File(destinationDir, zipEntry.getName());
+
+        String destDirPath = destinationDir.getCanonicalPath();
+        String destFilePath = destFile.getCanonicalPath();
+
+        if (!destFilePath.startsWith(destDirPath + File.separator)) {
+            throw new IOException("Entry is outside of the target dir: " + zipEntry.getName());
+        }
+
+        return destFile;
+    }
+
 }