Add repositories configuration option in swift-java.config

Package.swift

@@ -483,7 +483,7 @@ let package = Package(
     .testTarget(
       name: "SwiftJavaTests",
       dependencies: [
-        "SwiftJava", 
+        "SwiftJava",
         "JavaNet"
       ],
       swiftSettings: [
@@ -518,6 +518,9 @@ let package = Package(
       dependencies: [
         "SwiftJavaToolLib"
       ],
+      exclude: [
+        "SimpleJavaProject",
+      ],
       swiftSettings: [
         .swiftLanguageMode(.v5),
         .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"])

Samples/JavaDependencySampleApp/Package.swift

@@ -67,7 +67,8 @@ let package = Package(
         .product(name: "SwiftJava", package: "swift-java"),
         .product(name: "CSwiftJavaJNI", package: "swift-java"),
         .product(name: "JavaUtilFunction", package: "swift-java"),
-        "JavaCommonsCSV"
+        "JavaCommonsCSV",
+        "OrgAndrejsJson",
       ],
       exclude: ["swift-java.config"],
       swiftSettings: [
@@ -99,6 +100,25 @@ let package = Package(
       ]
     ),
 
+    .target(
+      name: "OrgAndrejsJson",
+      dependencies: [
+        .product(name: "SwiftJava", package: "swift-java"),
+        .product(name: "JavaUtilFunction", package: "swift-java"),
+        .product(name: "JavaUtil", package: "swift-java"),
+        .product(name: "JavaIO", package: "swift-java"),
+        .product(name: "JavaNet", package: "swift-java"),
+      ],
+      exclude: ["swift-java.config"],
+      swiftSettings: [
+        .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"]),
+        .swiftLanguageMode(.v5),
+      ],
+      plugins: [
+        .plugin(name: "SwiftJavaPlugin", package: "swift-java"),
+      ]
+    ),
+
     .target(name: "JavaExample"),
 
   ]

Samples/JavaDependencySampleApp/Sources/JavaDependencySample/OrgAndrejsJsonTests.swift

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import SwiftJava
+
+// Import the json library wrapper:
+import OrgAndrejsJson
+
+enum OrgAndrejsJsonTests {
+    static func run() async throws {
+        print("Now testing Json library...")
+
+        let json = Json(#"{"host": "localhost", "port": 80}"#)
+
+        precondition(json.hasOwnProperty("port"))
+        let port: JavaInteger = json.get("port")!
+
+        precondition(port.toString() == "80")
+        precondition(port.intValue() == 80)
+
+        print("Reading swift-java.config inside OrgAndrejsJson folder...")
+
+        let configPath = String.currentWorkingDirectory.appending("/Sources/OrgAndrejsJson/swift-java.config")
+
+        let config = try JavaClass<Json>().of.url("file://" + configPath)!
+
+        precondition(config.hasOwnProperty("repositories"))
+
+        print(config.toString())
+    }
+}
+
+private extension String {
+    static var currentWorkingDirectory: Self {
+        let path = getcwd(nil, 0)!
+        defer { free(path) }
+        return String(cString: path)
+    }
+}

Samples/JavaDependencySampleApp/Sources/JavaDependencySample/main.swift

@@ -52,4 +52,6 @@ for record in try CSVFormatClass.RFC4180.parse(reader)!.getRecords()! {
   }
 }
 
+try await OrgAndrejsJsonTests.run()
+
 print("Done.")

Samples/JavaDependencySampleApp/Sources/OrgAndrejsJson/dummy.swift

@@ -0,0 +1,13 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//

Samples/JavaDependencySampleApp/Sources/OrgAndrejsJson/swift-java.config

@@ -0,0 +1,15 @@
+{
+  "classes": {
+    "org.andrejs.json.Json": "Json",
+    "org.andrejs.json.JsonFactory": "JsonFactory"
+  },
+  "dependencies": [
+    "org.andrejs:json:1.2"
+  ],
+  "repositories": [
+    {
+      "type": "maven",
+      "url": "https://jitpack.io"
+    }
+  ]
+}

Sources/SwiftJavaConfigurationShared/Configuration.swift

@@ -99,6 +99,12 @@ public struct Configuration: Codable {
 
   // Java dependencies we need to fetch for this target.
   public var dependencies: [JavaDependencyDescriptor]?
+  /// Maven repositories for this target when fetching dependencies.
+  ///
+  /// `mavenCentral()` will always be used.
+  ///
+  /// Reference: [Repository Types](https://docs.gradle.org/current/userguide/supported_repository_types.html)
+  public var repositories: [JavaRepositoryDescriptor]?
 
   public init() {
   }
@@ -152,6 +158,82 @@ public struct JavaDependencyDescriptor: Hashable, Codable {
   }
 }
 
+/// Descriptor for [repositories](https://docs.gradle.org/current/userguide/supported_repository_types.html#sec:maven-repo)
+public enum JavaRepositoryDescriptor: Hashable, Codable, Equatable {
+
+  /// Haven't found a proper way to test credentials, packages that need to download from private repo can be downloaded by maven and then use local repo instead
+  /// 
+  /// References: 
+  ///   - [Maven repositories](https://docs.gradle.org/current/userguide/supported_repository_types.html#sec:maven-repo)
+  ///   - [Artifacts](https://docs.gradle.org/current/dsl/org.gradle.api.artifacts.repositories.MavenArtifactRepository.html#:~:text=urls)-,Adds%20some%20additional%20URLs%20to%20use%20to%20find%20artifact%20files.%20Note%20that%20these%20URLs%20are%20not%20used%20to%20find%20POM%20files.,-The)
+  case maven(url: String, artifactUrls: [String]? = nil)
+  case mavenLocal(includeGroups: [String]? = nil)
+  case other(_ type: String)
+
+  enum CodingKeys: String, CodingKey { case type, url, artifactUrls, credentials, includeGroups }
+
+  public init(from decoder: Decoder) throws {
+    let c = try decoder.container(keyedBy: CodingKeys.self)
+    let type = try c.decode(String.self, forKey: .type)
+    switch type {
+    case "maven":
+      self = try .maven(
+        url: c.decode(String.self, forKey: .url),
+        artifactUrls: try? c.decode([String].self, forKey: .artifactUrls),
+      )
+    case "mavenLocal":
+      self = .mavenLocal(includeGroups: try? c.decode([String].self, forKey: .includeGroups))
+    default:
+      self = .other(type)
+    }
+  }
+
+  public func encode(to encoder: Encoder) throws {
+    var c = encoder.container(keyedBy: CodingKeys.self)
+    switch self {
+    case let .maven(url, artifactUrls/*, creds*/):
+      try c.encode("maven", forKey: .type)
+      try c.encode(url, forKey: .url)
+      if let artifactUrls = artifactUrls {
+        try c.encode(artifactUrls, forKey: .artifactUrls)
+      }
+    case let .mavenLocal(includeGroups):
+      try c.encode("mavenLocal", forKey: .type)
+      if let gs = includeGroups {
+        try c.encode(gs, forKey: .includeGroups)
+      }
+    case let .other(type):
+      try c.encode("\(type)", forKey: .type)
+    }
+  }
+
+  public func renderGradleRepository() -> String? {
+    switch self {
+    case let .maven(url, artifactUrls):
+      return """
+        maven {
+          url = uri("\(url)")
+          \((artifactUrls ?? []).map({ "artifactUrls(\"\($0)\")" }).joined(separator: "\n"))
+        }
+        """
+    case let .mavenLocal(groups):
+      if let gs = groups {
+        return """
+          mavenLocal {
+            content {
+              \(gs.map({ "includeGroup(\"\($0)\")" }).joined(separator: "\n"))
+            }
+          }
+          """
+      } else {
+          return "mavenLocal()"
+      }
+    case let .other(type):
+      return "\(type)()"
+    }
+  }
+}
+
 public func readConfiguration(sourceDir: String, file: String = #fileID, line: UInt = #line) throws -> Configuration? {
   // Workaround since filePath is macOS 13
   let sourcePath =

Sources/SwiftJavaDocumentation/Documentation.docc/SwiftJavaCommandLineTool.md

@@ -199,9 +199,89 @@ struct HelloSwiftMain: ParsableCommand {
 
 ### Download Java dependencies in Swift builds: swift-java resolve
 
-> TIP: See the `Samples/DependencySampleApp` for a fully functional showcase of this mode.
+> TIP: See the `Samples/JavaDependencySampleApp` for a fully functional showcase of this mode.
 
-TODO: documentation on this feature
+
+The `swift-java resolve` command automates the process of downloading and resolving Java dependencies for your Swift project. This is configured through your `swift-java.config` file, where you can declare both the dependencies you need and the repositories from which to fetch them.
+
+To get started, add a `dependencies` array to your configuration file, listing the Maven coordinates for each required library (e.g., `group:artifact:version`). You may also include a `repositories` array to specify custom Maven repositories. For example:
+
+```json
+{
+  "classes": {
+    "org.apache.commons.io.FilenameUtils": "FilenameUtils",
+    "org.apache.commons.io.IOCase": "IOCase",
+    "org.apache.commons.csv.CSVFormat": "CSVFormat",
+    "org.apache.commons.csv.CSVParser": "CSVParser",
+    "org.apache.commons.csv.CSVRecord": "CSVRecord"
+  },
+  "dependencies": [
+    "org.apache.commons:commons-csv:1.12.0"
+  ]
+}
+```
+
+To resolve and download these dependencies, run:
+
+```bash
+# See Samples/JavaDependencySampleApp/ci-validate.sh for a complete example
+swift-java resolve \
+  swift-java.config \
+  --swift-module JavaCommonsCSV \
+  --output-directory .build/plugins/JavaCommonsCSV/destination/SwiftJavaPlugin/
+```
+
+The tool will fetch all specified dependencies from the repositories listed in your config (or Maven Central by default), and generate a `swift-java.classpath` file. This file is then used for building and running your Swift-Java interop code.
+
+If you do not specify any `repositories`, dependencies are resolved from Maven Central. To use a custom or private repository, add it to the `repositories` array, for example:
+
+```json
+{
+  "repositories": [
+    { "type": "maven", "url": "https://repo.mycompany.com/maven2" },
+    {
+      "type": "maven",
+      "url": "https://repo2.mycompany.com/maven2",
+      "artifactUrls": [
+        "https://repo.mycompany.com/jars",
+        "https://repo.mycompany.com/jars2"
+      ]
+    },
+    { "type": "maven", "url": "https://secure.repo.com/maven2" },
+    { "type": "mavenLocal", "includeGroups": ["com.example.myproject"] },
+    { "type": "maven", "url": "build/repo" }, // Relative to build folder of the temporary project, better to use absolute path here, no need to add `file:` prefix
+    { "type": "mavenCentral" },
+    { "type": "mavenLocal" },
+    { "type": "google" }
+  ]
+}
+```
+
+> Note: [Authentication for private repositories is not currently handled directly by `swift-java`](https://github.com/swiftlang/swift-java/issues/382). If you need to access packages from a private repository that requires credentials, you can use Maven to download the required artifacts and then reference them via your local Maven repository in your configuration.
+
+For practical usage, refer to `Samples/JavaDependencySampleApp` and the tests in `Tests/SwiftJavaTests/JavaRepositoryTests.swift`.
+
+This workflow streamlines Java dependency management for Swift projects, letting you use Java libraries without manually downloading JAR files.
+
+#### About the `classes` section
+
+The `classes` section in your `swift-java.config` file specifies which Java classes should be made available in Swift, and what their corresponding Swift type names should be. Each entry maps a fully-qualified Java class name to a Swift type name. For example:
+
+```json
+{
+  "classes": {
+    "org.apache.commons.io.FilenameUtils" : "FilenameUtils",
+    "org.apache.commons.io.IOCase" : "IOCase",
+    "org.apache.commons.csv.CSVFormat" : "CSVFormat",
+    "org.apache.commons.csv.CSVParser" : "CSVParser",
+    "org.apache.commons.csv.CSVRecord" : "CSVRecord"
+  }
+}
+```
+
+When you run `swift-java wrap-java` (or build your project with the plugin), Swift source files are generated for each mapped class. For instance, the above config will result in `CSVFormat.swift`, `CSVParser.swift`, `CSVRecord.swift`, `FilenameUtils.swift` and `IOCase.swift` files, each containing a Swift class that wraps the corresponding Java class and exposes its constructors, methods, and fields for use in Swift.
+
+This mapping allows you to use Java APIs directly from Swift, with type-safe wrappers and automatic bridging of method calls and data types.
 
 ### Expose Swift code to Java: swift-java jextract