Add properties json adapter

blackbox-test/src/main/java/org/example/customer/properties/Props.java

@@ -0,0 +1,11 @@
+package org.example.customer.properties;
+
+import io.avaje.jsonb.Json;
+
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.util.Properties;
+
+@Json
+public record Props(Properties props) {}

blackbox-test/src/test/java/org/example/customer/properties/PropsTest.java

@@ -0,0 +1,30 @@
+package org.example.customer.properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Properties;
+
+import org.junit.jupiter.api.Test;
+
+import io.avaje.jsonb.JsonType;
+import io.avaje.jsonb.Jsonb;
+
+class PropsTest {
+
+  Jsonb jsonb = Jsonb.builder().build();
+  JsonType<Props> jsonType = jsonb.type(Props.class);
+
+  @Test
+  void toJson_fromJson() {
+
+    Properties properties = new Properties();
+
+    properties.setProperty("hi", "hey");
+    Props props = new Props(properties);
+
+    String asJson = jsonType.toJson(props);
+    Props fromJson = jsonType.fromJson(asJson);
+
+    assertThat(fromJson.props()).containsEntry("hi", "hey");
+  }
+}

jsonb/src/main/java/io/avaje/jsonb/core/BasicTypeAdapters.java

@@ -29,6 +29,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Properties;
 import java.util.UUID;
 
 import io.avaje.json.JsonAdapter;
@@ -37,6 +38,7 @@
 import io.avaje.json.JsonWriter;
 import io.avaje.jsonb.AdapterFactory;
 import io.avaje.jsonb.Jsonb;
+import io.avaje.jsonb.Types;
 
 final class BasicTypeAdapters {
 
@@ -49,14 +51,15 @@ final class BasicTypeAdapters {
         if (type == Byte.class) return new ByteAdapter().nullSafe();
         if (type == Character.class) return new CharacterAdapter().nullSafe();
         if (type == Short.class) return new ShortAdapter().nullSafe();
+        if (type == Object.class) return new ObjectJsonAdapter(jsonb).nullSafe();
         if (type == UUID.class) return new UuidAdapter().nullSafe();
         if (type == URL.class) return new UrlAdapter().nullSafe();
         if (type == URI.class) return new UriAdapter().nullSafe();
-        if (type == InetAddress.class) return new InetAddressAdapter().nullSafe();
-        if (type == Inet4Address.class) return new InetAddressAdapter().nullSafe();
-        if (type == Inet6Address.class) return new InetAddressAdapter().nullSafe();
+        if (type == Properties.class) return new PropertiesAdapter(jsonb).nullSafe();
+        if (type == InetAddress.class || type == Inet4Address.class || type == Inet6Address.class) {
+          return new InetAddressAdapter().nullSafe();
+        }
         if (type == StackTraceElement.class) return new StackTraceElementAdapter().nullSafe();
-        if (type == Object.class) return new ObjectJsonAdapter(jsonb).nullSafe();
         if (type == Throwable.class) return new ThrowableAdapter(jsonb).nullSafe();
 
         final Class<?> rawType = Util.rawType(type);
@@ -121,6 +124,35 @@ public String toString() {
     }
   }
 
+  private static final class PropertiesAdapter implements JsonAdapter<Properties> {
+    private JsonAdapter<Map<Object, Object>> mapAdapter;
+
+    private PropertiesAdapter(Jsonb jsonb) {
+      this.mapAdapter = jsonb.adapter(Types.mapOf(Object.class));
+    }
+
+    @Override
+    public Properties fromJson(JsonReader reader) {
+      var map = mapAdapter.fromJson(reader);
+      if (map == null) {
+        return null;
+      }
+      var properties = new Properties();
+      properties.putAll(map);
+      return properties;
+    }
+
+    @Override
+    public void toJson(JsonWriter writer, Properties value) {
+      mapAdapter.toJson(writer, value);
+    }
+
+    @Override
+    public String toString() {
+      return "JsonAdapter(Properties)";
+    }
+  }
+
   private static final class InetAddressAdapter implements JsonAdapter<InetAddress> {
     @Override
     public InetAddress fromJson(JsonReader reader) {