fix: handle big .jar files (using multi-dex option) (#390) (PR #568)

jadx-core/src/main/java/jadx/core/utils/files/InputFile.java

 package jadx.core.utils.files;
 
+import static jadx.core.utils.files.FileUtils.isApkFile;
+import static jadx.core.utils.files.FileUtils.isZipDexFile;
+
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
@@ -11,20 +16,18 @@ import java.util.jar.JarOutputStream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
-import com.android.dex.Dex;
 import org.apache.commons.io.IOUtils;
 import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.android.dex.Dex;
+
 import jadx.core.utils.AsmUtils;
 import jadx.core.utils.exceptions.DecodeException;
 import jadx.core.utils.exceptions.JadxException;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
-import static jadx.core.utils.files.FileUtils.isApkFile;
-import static jadx.core.utils.files.FileUtils.isZipDexFile;
-
 public class InputFile {
 	private static final Logger LOG = LoggerFactory.getLogger(InputFile.class);
 
@@ -52,7 +55,9 @@ public class InputFile {
 			return;
 		}
 		if (fileName.endsWith(".class")) {
-			addDexFile(loadFromClassFile(file));
+			for (Dex dex : loadFromClassFile(file)) {
+				addDexFile(dex);
+			}
 			return;
 		}
 		if (isApkFile(file) || isZipDexFile(file)) {
@@ -65,7 +70,9 @@ public class InputFile {
 				return;
 			}
 			if (fileName.endsWith(".jar")) {
-				addDexFile(loadFromJar(file));
+				for (Dex dex : loadFromJar(file.toPath())) {
+					addDexFile(dex);
+				}
 				return;
 			}
 			if (fileName.endsWith(".aar")) {
@@ -116,11 +123,11 @@ public class InputFile {
 
 							case ".jar":
 								index++;
-								File jarFile = FileUtils.createTempFile(entryName);
-								try (FileOutputStream fos = new FileOutputStream(jarFile)) {
-									IOUtils.copy(inputStream, fos);
+								Path jarFile = Files.createTempFile(entryName, ".jar");
+								Files.copy(inputStream, jarFile);
+								for (Dex dex : loadFromJar(jarFile)) {
+									addDexFile(entryName, dex);
 								}
-								addDexFile(entryName, loadFromJar(jarFile));
 								break;
 
 							default:
@@ -155,15 +162,19 @@ public class InputFile {
 		}
 	}
 
-	private static Dex loadFromJar(File jarFile) throws DecodeException {
+	private static List<Dex> loadFromJar(Path jar) throws DecodeException {
 		JavaToDex j2d = new JavaToDex();
 		try {
-			LOG.info("converting to dex: {} ...", jarFile.getName());
-			byte[] ba = j2d.convert(jarFile.getAbsolutePath());
-			if (ba.length == 0) {
+			LOG.info("converting to dex: {} ...", jar.getFileName());
+			List<byte[]> byteList = j2d.convert(jar);
+			if (byteList.isEmpty()) {
 				throw new JadxException("Empty dx output");
 			}
-			return new Dex(ba);
+			List<Dex> dexList = new ArrayList<>(byteList.size());
+			for (byte[] b : byteList) {
+				dexList.add(new Dex(b));
+			}
+			return dexList;
 		} catch (Exception e) {
 			throw new DecodeException("java class to dex conversion error:\n " + e.getMessage(), e);
 		} finally {
@@ -173,9 +184,9 @@ public class InputFile {
 		}
 	}
 
-	private static Dex loadFromClassFile(File file) throws IOException, DecodeException {
-		File outFile = FileUtils.createTempFile("cls.jar");
-		try (JarOutputStream jo = new JarOutputStream(new FileOutputStream(outFile))) {
+	private static List<Dex> loadFromClassFile(File file) throws IOException, DecodeException {
+		Path outFile = Files.createTempFile("cls", ".jar");
+		try (JarOutputStream jo = new JarOutputStream(Files.newOutputStream(outFile))) {
 			String clsName = AsmUtils.getNameFromClassFile(file);
 			if (clsName == null || !ZipSecurity.isValidZipEntryName(clsName)) {
 				throw new IOException("Can't read class name from file: " + file);

jadx-core/src/main/java/jadx/core/utils/files/JavaToDex.java

 package jadx.core.utils.files;
 
 import java.io.ByteArrayOutputStream;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
 
 import com.android.dx.command.dexer.DxContext;
 import com.android.dx.command.dexer.Main;
@@ -13,11 +18,12 @@ public class JavaToDex {
 	private static final String CHARSET_NAME = "UTF-8";
 
 	private static class DxArgs extends Arguments {
-		public DxArgs(DxContext context, String dexFile, String[] input) {
+		public DxArgs(DxContext context, String dexDir, String[] input) {
 			super(context);
-			outName = dexFile;
+			outName = dexDir;
 			fileNames = input;
 			jarOutput = false;
+			multiDex = true;
 
 			optimize = true;
 			localInfo = true;
@@ -31,17 +37,29 @@ public class JavaToDex {
 
 	private String dxErrors;
 
-	public byte[] convert(String javaFile) throws JadxException {
+	public List<byte[]> convert(Path jar) throws JadxException {
 		try (ByteArrayOutputStream out = new ByteArrayOutputStream();
 		     ByteArrayOutputStream errOut = new ByteArrayOutputStream()) {
 			DxContext context = new DxContext(out, errOut);
-			DxArgs args = new DxArgs(context, "-", new String[]{javaFile});
-			int result = (new Main(context)).runDx(args);
+			Path dir = Files.createTempDirectory("jadx");
+			DxArgs args = new DxArgs(
+					context,
+					dir.toAbsolutePath().toString(),
+					new String[]{jar.toAbsolutePath().toString()});
+			int result = new Main(context).runDx(args);
 			dxErrors = errOut.toString(CHARSET_NAME);
 			if (result != 0) {
 				throw new JadxException("Java to dex conversion error, code: " + result);
 			}
-			return out.toByteArray();
+			List<byte[]> list = new ArrayList<>();
+	        try (DirectoryStream<Path> ds = Files.newDirectoryStream(dir)) {
+	            for (Path child : ds) {
+	            	list.add(Files.readAllBytes(child));
+	            	Files.delete(child);
+	            }
+	        }
+	        Files.delete(dir);
+	        return list;
 		} catch (Exception e) {
 			throw new JadxException("dx exception: " + e.getMessage(), e);
 		}