Answering your question – Yes, actually, it’s possible to build an iOS app with Java. You can find some information about the procedure and even long step-by-step lists of how to do this over the Internet.
Can you build apps with Java?
Use Android Studio and Java to write Android apps
You write Android apps in the Java programming language using an IDE called Android Studio. Based on JetBrains’ IntelliJ IDEA software, Android Studio is an IDE designed specifically for Android development.
What programming language is used to develop iOS apps?
Swift is a powerful and intuitive programming language for macOS, iOS, watchOS, tvOS and beyond. Writing Swift code is interactive and fun, the syntax is concise yet expressive, and Swift includes modern features developers love. Swift code is safe by design, yet also produces software that runs lightning-fast.