add putRecordToNBT

Author: CoolLoong

src/main/java/org/cloudburstmc/nbt/NbtUtils.java

@@ -1,11 +1,14 @@
 package org.cloudburstmc.nbt;
 
+import org.cloudburstmc.nbt.annotation.NBT;
 import org.cloudburstmc.nbt.util.stream.LittleEndianDataInputStream;
 import org.cloudburstmc.nbt.util.stream.LittleEndianDataOutputStream;
 import org.cloudburstmc.nbt.util.stream.NetworkDataInputStream;
 import org.cloudburstmc.nbt.util.stream.NetworkDataOutputStream;
 
 import java.io.*;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.StringJoiner;
 import java.util.zip.GZIPInputStream;
@@ -140,4 +143,30 @@ public static String printHexBinary(byte[] data) {
         }
         return r.toString();
     }
+
+    /**
+     * Write each {@link java.lang.reflect.RecordComponent RecordComponent} from record that be marked {@link NBT} to the specified nbtMap
+     *
+     * @param record the record
+     * @param nbtMap the nbtmap
+     * @return result NBT
+     */
+    public static NbtMap putRecordToNBT(Record record, NbtMap nbtMap) {
+        Class<? extends Record> clazz = record.getClass();
+        NBT annotation = clazz.getAnnotation(NBT.class);
+        if (annotation == null) {
+            throw new IllegalArgumentException("This record does not use @NBT annotation!");
+        }
+        NbtMapBuilder builder = NbtMapBuilder.from(nbtMap);
+        for (var c : clazz.getRecordComponents()) {
+            String name = c.getName();
+            Method accessor = c.getAccessor();
+            try {
+                builder.put(name, accessor.invoke(record));
+            } catch (IllegalAccessException | InvocationTargetException e) {
+                throw new RuntimeException(e);
+            }
+        }
+        return builder.build();
+    }
 }

src/test/java/org/cloudburstmc/nbt/NbtTest.java

@@ -68,6 +68,18 @@ record Data(int a, int b, int c) {
                 {"a":1,"b":2,"c":3}""");
     }
 
+    @Test
+    void testPutRecordToNBT() {
+        @NBT
+        record Data(int a, int b, int c) {
+        }
+        NbtMapBuilder builder = new NbtMapBuilder();
+        builder.putString("test", "test nbt");
+        NbtMap build = builder.build();
+        Assertions.assertEquals(NbtUtils.putRecordToNBT(new Data(1, 2, 3), build).toSNBT(), """
+                {"test":"test nbt","a":1,"b":2,"c":3}""");
+    }
+
     @Test
     @DisplayName("Network Encoding Test")
     void networkTest() {
@@ -92,7 +104,7 @@ void networkTest() {
     void biomeDefinitionsTest() {
         InputStream stream = NbtTest.class.getClassLoader().getResourceAsStream("biome_definitions.nbt");
         try (NBTInputStream in = NbtUtils.createNetworkReader(stream)) {
-            Object o = in.readTag();
+            NbtMap o = (NbtMap) in.readTag();
         } catch (Exception e) {
             e.printStackTrace();
             throw new AssertionError("Error whilst decoding tag", e);