Improve JAVA_HOME detection with SDKMAN and PATH Fallback

Sources/SwiftJavaToolLib/JavaHomeSupport.swift

@@ -42,6 +42,15 @@ public func findJavaHome() -> String {
     return home
   }
 
+  if let home = getJavaHomeFromSDKMAN() {
+    return home
+  }
+
+  if let home = getJavaHomeFromPath() {
+    return home
+  }
+
+
   if ProcessInfo.processInfo.environment["SPI_PROCESSING"] == "1"
     && ProcessInfo.processInfo.environment["SPI_BUILD"] == nil
   {
@@ -90,3 +99,45 @@ public func getJavaHomeFromLibexecJavaHome() -> String? {
     return nil
   }
 }
+
+// MARK: - Additional Java discovery fallbacks
+
+func getJavaHomeFromSDKMAN() -> String? {
+  let home = FileManager.default.homeDirectoryForCurrentUser
+    .appendingPathComponent(".sdkman/candidates/java/current")
+
+  let javaBin = home.appendingPathComponent("bin/java").path
+  if FileManager.default.isExecutableFile(atPath: javaBin) {
+    return home.path
+  }
+  return nil
+}
+
+func getJavaHomeFromPath() -> String? {
+  let task = Process()
+  task.executableURL = URL(fileURLWithPath: "/usr/bin/which")
+  task.arguments = ["java"]
+
+  let pipe = Pipe()
+  task.standardOutput = pipe
+
+  do {
+    try task.run()
+    task.waitUntilExit()
+    guard task.terminationStatus == 0 else { return nil }
+
+    let data = pipe.fileHandleForReading.readDataToEndOfFile()
+    guard let javaPath = String(data: data, encoding: .utf8)?
+      .trimmingCharacters(in: .whitespacesAndNewlines),
+      !javaPath.isEmpty
+    else { return nil }
+
+    let resolved = URL(fileURLWithPath: javaPath).resolvingSymlinksInPath()
+    return resolved
+      .deletingLastPathComponent()
+      .deletingLastPathComponent()
+      .path
+  } catch {
+    return nil
+  }
+}