Java to Swift Converter
Port Android Java applications to iOS Swift with AI-powered cross-platform conversion. Transforms Java classes to Swift protocols and structs, ArrayList to Swift Arrays, HashMap to Dictionary, and Java interfaces to protocol-oriented patterns. Converts Android business logic for iOS deployment, handling optionals for null safety and Grand Central Dispatch for concurrency—accelerating Android-to-iOS migration projects.
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Issue Description
Hint: Describe what you want to build or paste requirements, select target language, and click Generate.
How It Works
- Step 1: Paste your Java source code including class definitions, interface declarations, generic types, and business logic suitable for cross-platform use.
- Step 2: The AI identifies Java patterns like null references requiring Swift optionals, Collection types mapping to Swift native containers, and interface contracts converting to protocols.
- Step 3: Advanced transformation generates Swift code with protocol-oriented design, value types where appropriate, automatic reference counting patterns, and iOS-specific idioms.
- Step 4: Download Swift code with optional chaining, protocol extensions, enum associated values, and modern concurrency ready for Xcode integration and iOS deployment.
Java vs Swift: Language Comparison
| Feature | Java | Swift |
|---|---|---|
| Syntax Style | Verbose OOP with explicit types | Protocol-oriented, type inference |
| Null Safety | @Nullable annotations | Built-in optionals (?, !) |
| Memory Management | JVM garbage collection | ARC (Automatic Reference Counting) |
| Concurrency | Threads, ExecutorService | Grand Central Dispatch, async/await |
| Collections | java.util Collections | Swift Array, Dictionary, Set |
Code Conversion Examples
Example 1: Collections and Generics
import java.util.*;
public class UserManager<T extends User> {
private List<T> users;
private Map<String, T> userIndex;
public UserManager() {
this.users = new ArrayList<>();
this.userIndex = new HashMap<>();
}
public void addUser(T user) {
users.add(user);
userIndex.put(user.getId(), user);
}
public T findUser(String id) {
return userIndex.get(id);
}
public List<T> getActiveUsers() {
return users.stream()
.filter(User::isActive)
.collect(Collectors.toList());
}
}class UserManager<T: User> {
private var users: [T] = []
private var userIndex: [String: T] = [:]
func addUser(_ user: T) {
users.append(user)
userIndex[user.id] = user
}
func findUser(_ id: String) -> T? {
return userIndex[id]
}
func getActiveUsers() -> [T] {
return users.filter { $0.isActive }
}
}Key Changes:
Java's generic constraints (T extends User) become Swift protocol constraints (T: User). ArrayList converts to Swift Array with native syntax, HashMap becomes Dictionary with bracket notation. The Stream API with filter/collect transforms to Swift's functional filter method. Null returns become Swift optionals (T?). Method parameters use external names (_) for Swift conventions. Closures ($0) replace verbose lambda syntax.
Example 2: Interfaces to Protocols
public interface DataSource {
String fetchData(String key);
void saveData(String key, String value);
boolean hasData(String key);
}
public class LocalDataSource implements DataSource {
private Map<String, String> storage = new HashMap<>();
@Override
public String fetchData(String key) {
return storage.get(key);
}
@Override
public void saveData(String key, String value) {
storage.put(key, value);
}
@Override
public boolean hasData(String key) {
return storage.containsKey(key);
}
}
public class DataManager {
private DataSource dataSource;
public DataManager(DataSource dataSource) {
this.dataSource = dataSource;
}
public String loadData(String key) {
if (dataSource.hasData(key)) {
return dataSource.fetchData(key);
}
return "Default";
}
}protocol DataSource {
func fetchData(key: String) -> String?
func saveData(key: String, value: String)
func hasData(key: String) -> Bool
}
class LocalDataSource: DataSource {
private var storage: [String: String] = [:]
func fetchData(key: String) -> String? {
return storage[key]
}
func saveData(key: String, value: String) {
storage[key] = value
}
func hasData(key: String) -> Bool {
return storage.keys.contains(key)
}
}
class DataManager {
private let dataSource: DataSource
init(dataSource: DataSource) {
self.dataSource = dataSource
}
func loadData(key: String) -> String {
if dataSource.hasData(key: key),
let data = dataSource.fetchData(key: key) {
return data
}
return "Default"
}
}Key Changes:
Java interfaces become Swift protocols with identical method signatures. The @Override annotation is unnecessary—protocol conformance is automatic. Nullable returns use Swift optionals (?). HashMap storage converts to Dictionary with bracket syntax. Constructors become init methods with parameter names. Optional binding (if let) replaces null checks. Protocol-oriented design enables value types and better testability in Swift.
Frequently Asked Questions
Can I configure whether Java classes become Swift classes or structs?
The converter generates Swift classes by default to preserve Java's reference semantics. Value types (structs) require manual post-processing based on your app architecture. Advanced heuristics (immutable classes → structs) are not supported. The tool prioritizes semantic correctness over performance optimization.
Is my Java code sent to external servers?
Yes. AI conversion requires server-side LLM processing. Your Java source is transmitted over HTTPS to our API, converted, then discarded. We do not store code or train models on submissions. Review data policies before converting proprietary Android app code.
What Java/Android features cannot be converted?
Android framework APIs (Activities, Fragments, Views) lack direct Swift equivalents—conversion focuses on business logic. JNI code, Java reflection, and runtime class loading have no Swift mappings. The tool excels at algorithm and data structure conversion but struggles with framework-specific code.