From 1aa3c1e543197ce34ceafeb407ea268d044f029a Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@gmail.com>
Date: Thu, 18 Aug 2022 16:41:28 +0200
Subject: [PATCH] java/String: add static method Optional()

---
 src/java/String.hxx | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/java/String.hxx b/src/java/String.hxx
index f60e7abc7..716268f02 100644
--- a/src/java/String.hxx
+++ b/src/java/String.hxx
@@ -89,6 +89,16 @@ public:
 	String(JNIEnv *_env, const char *_value) noexcept
 		:LocalRef<jstring>(_env, _env->NewStringUTF(_value)) {}
 
+	/**
+	 * This constructor allows passing a nullptr value, which maps
+	 * to a "null" in Java.
+	 */
+	static String Optional(JNIEnv *_env, const char *_value) noexcept {
+		return _value != nullptr
+			? String{_env, _value}
+			: String{};
+	}
+
 	static StringUTFChars GetUTFChars(JNIEnv *env, jstring s) noexcept {
 		return {env, s, env->GetStringUTFChars(s, nullptr)};
 	}