fix: prevent collisions in method ids for java-input

jadx-plugins/jadx-java-input/src/main/java/jadx/plugins/input/java/JavaFileLoader.java

@@ -21,22 +21,22 @@ import jadx.api.plugins.utils.ZipSecurity;
 public class JavaFileLoader {
 	private static final Logger LOG = LoggerFactory.getLogger(JavaFileLoader.class);
 
-	public static final int MAX_MAGIC_SIZE = 4;
-	public static final byte[] JAVA_CLASS_FILE_MAGIC = { (byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE };
-	public static final byte[] ZIP_FILE_MAGIC = { 0x50, 0x4B, 0x03, 0x04 };
+	private static final int MAX_MAGIC_SIZE = 4;
+	private static final byte[] JAVA_CLASS_FILE_MAGIC = { (byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE };
+	private static final byte[] ZIP_FILE_MAGIC = { 0x50, 0x4B, 0x03, 0x04 };
 
-	private static int classUniqId = 1;
+	private int classUniqId = 1;
 
-	public static List<JavaClassReader> collectFiles(List<Path> inputFiles) {
+	public List<JavaClassReader> collectFiles(List<Path> inputFiles) {
 		return inputFiles.stream()
 				.map(Path::toFile)
-				.map(JavaFileLoader::loadFromFile)
+				.map(this::loadFromFile)
 				.filter(list -> !list.isEmpty())
 				.flatMap(Collection::stream)
 				.collect(Collectors.toList());
 	}
 
-	private static List<JavaClassReader> loadFromFile(File file) {
+	private List<JavaClassReader> loadFromFile(File file) {
 		try (InputStream inputStream = new BufferedInputStream(new FileInputStream(file))) {
 			return loadReader(file, inputStream, file.getAbsolutePath());
 		} catch (Exception e) {
@@ -45,7 +45,7 @@ public class JavaFileLoader {
 		}
 	}
 
-	private static List<JavaClassReader> loadReader(File file, InputStream in, String inputFileName) throws IOException {
+	private List<JavaClassReader> loadReader(File file, InputStream in, String inputFileName) throws IOException {
 		byte[] magic = new byte[MAX_MAGIC_SIZE];
 		if (in.read(magic) != magic.length) {
 			return Collections.emptyList();
@@ -61,7 +61,7 @@ public class JavaFileLoader {
 		return Collections.emptyList();
 	}
 
-	private static List<JavaClassReader> collectFromZip(File file) {
+	private List<JavaClassReader> collectFromZip(File file) {
 		List<JavaClassReader> result = new ArrayList<>();
 		try {
 			ZipSecurity.readZipEntries(file, (entry, in) -> {
@@ -94,7 +94,7 @@ public class JavaFileLoader {
 		int estimateSize = prefix.length + in.available();
 		ByteArrayOutputStream out = new ByteArrayOutputStream(estimateSize);
 		out.write(prefix);
-		byte[] buffer = new byte[0xFFFF];
+		byte[] buffer = new byte[8 * 1024];
 		while (true) {
 			int len = in.read(buffer);
 			if (len == -1) {
@@ -105,11 +105,7 @@ public class JavaFileLoader {
 		return out.toByteArray();
 	}
 
-	private static int getNextUniqId() {
-		classUniqId++;
-		if (classUniqId >= 0xFFFF) {
-			classUniqId = 1;
-		}
-		return classUniqId;
+	private int getNextUniqId() {
+		return classUniqId++;
 	}
 }

jadx-plugins/jadx-java-input/src/main/java/jadx/plugins/input/java/JavaInputPlugin.java

@@ -22,7 +22,7 @@ public class JavaInputPlugin implements JadxInputPlugin {
 
 	@Override
 	public ILoadResult loadFiles(List<Path> inputFiles) {
-		List<JavaClassReader> readers = JavaFileLoader.collectFiles(inputFiles);
+		List<JavaClassReader> readers = new JavaFileLoader().collectFiles(inputFiles);
 		if (readers.isEmpty()) {
 			return EmptyLoadResult.INSTANCE;
 		}

jadx-plugins/jadx-java-input/src/main/java/jadx/plugins/input/java/data/ConstPoolReader.java

@@ -78,7 +78,7 @@ public class ConstPoolReader {
 		int descIdx = data.readU2();
 
 		JavaMethodRef mthRef = new JavaMethodRef();
-		mthRef.initUniqId(clsReader, clsIdx, nameIdx, descIdx);
+		mthRef.initUniqId(clsReader, idx, true);
 		mthRef.setParentClassType(getClass(clsIdx));
 		mthRef.setName(getUtf8(nameIdx));
 		mthRef.setDescr(getUtf8(descIdx));

jadx-plugins/jadx-java-input/src/main/java/jadx/plugins/input/java/data/JavaClassData.java

@@ -94,7 +94,7 @@ public class JavaClassData implements IClassData {
 			methodRef.setParentClassType(classType);
 			JavaMethodData method = new JavaMethodData(this, methodRef);
 			for (int i = 0; i < methodsCount; i++) {
-				parseMethod(reader, method, clsIdx);
+				parseMethod(reader, method, i);
 				mthConsumer.accept(method);
 			}
 		}
@@ -112,7 +112,7 @@ public class JavaClassData implements IClassData {
 		field.setAttributes(attributes);
 	}
 
-	private void parseMethod(DataReader reader, JavaMethodData method, int clsIdx) {
+	private void parseMethod(DataReader reader, JavaMethodData method, int id) {
 		int accessFlags = reader.readU2();
 		int nameIdx = reader.readU2();
 		int descriptorIdx = reader.readU2();
@@ -120,7 +120,7 @@ public class JavaClassData implements IClassData {
 
 		JavaMethodRef methodRef = method.getMethodRef();
 		methodRef.reset();
-		methodRef.initUniqId(clsReader, clsIdx, nameIdx, descriptorIdx);
+		methodRef.initUniqId(clsReader, id, false);
 		methodRef.setName(constPoolReader.getUtf8(nameIdx));
 		methodRef.setDescr(constPoolReader.getUtf8(descriptorIdx));
 

jadx-plugins/jadx-java-input/src/main/java/jadx/plugins/input/java/data/JavaMethodRef.java

@@ -16,9 +16,15 @@ public class JavaMethodRef extends JavaMethodProto implements IMethodRef {
 		return uniqId;
 	}
 
-	public void initUniqId(JavaClassReader clsReader, int clsIdx, int nameIdx, int descIdx) {
-		// TODO: check for id overlap
-		this.uniqId = (clsReader.getId() & 0xFFF) << 20 | (clsIdx & 0xFF) << 12 | (nameIdx & 0xFF) << 4 | descIdx & 0xF;
+	public void initUniqId(JavaClassReader clsReader, int id, boolean fromConstPool) {
+		int readerId = clsReader.getId();
+		if (readerId > 0xFFFF || id > 0x7FFF) {
+			// loaded more than 65535 classes or more than 32767 methods in this class -> disable caching
+			this.uniqId = 0;
+		} else {
+			int source = fromConstPool ? 0 : 0x8000;
+			this.uniqId = (readerId & 0xFFFF) << 16 | source | id & 0x7FFF;
+		}
 	}
 
 	@Override