diff --git a/lang/java/avro/src/main/java/org/apache/avro/data/Json.java b/lang/java/avro/src/main/java/org/apache/avro/data/Json.java
index ca73cc32870..fe49245a69f 100644
--- a/lang/java/avro/src/main/java/org/apache/avro/data/Json.java
+++ b/lang/java/avro/src/main/java/org/apache/avro/data/Json.java
@@ -17,6 +17,7 @@
  */
 package org.apache.avro.data;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Iterator;
@@ -39,6 +40,7 @@
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DatumWriter;
 import org.apache.avro.io.Encoder;
+import org.apache.avro.io.EncoderFactory;
 import org.apache.avro.io.Decoder;
 import org.apache.avro.io.DecoderFactory;
 import org.apache.avro.io.ResolvingDecoder;
@@ -79,6 +81,14 @@ public void setSchema(Schema schema) {
     public void write(Object datum, Encoder out) throws IOException {
       Json.writeObject(datum, out);
     }
+
+    @Override
+    public byte[] toByteArray(Object datum) throws IOException {
+      try (ByteArrayOutputStream out = new ByteArrayOutputStream(128)) {
+        write(datum, EncoderFactory.get().directBinaryEncoder(out, null));
+        return out.toByteArray();
+      }
+    }
   }
 
   /**
diff --git a/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumWriter.java b/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumWriter.java
index deeac0b1f2b..159cf10fdef 100644
--- a/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumWriter.java
+++ b/lang/java/avro/src/main/java/org/apache/avro/generic/GenericDatumWriter.java
@@ -17,6 +17,7 @@
  */
 package org.apache.avro.generic;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ConcurrentModificationException;
@@ -32,6 +33,7 @@
 import org.apache.avro.LogicalType;
 import org.apache.avro.Schema;
 import org.apache.avro.Schema.Field;
+import org.apache.avro.io.EncoderFactory;
 import org.apache.avro.path.TracingAvroTypeException;
 import org.apache.avro.UnresolvedUnionException;
 import org.apache.avro.io.DatumWriter;
@@ -85,6 +87,14 @@ public void write(D datum, Encoder out) throws IOException {
     }
   }
 
+  @Override
+  public byte[] toByteArray(D datum) throws IOException {
+    try (ByteArrayOutputStream out = new ByteArrayOutputStream(128)) {
+      write(datum, EncoderFactory.get().directBinaryEncoder(out, null));
+      return out.toByteArray();
+    }
+  }
+
   /** Called to write data. */
   protected void write(Schema schema, Object datum, Encoder out) throws IOException {
     LogicalType logicalType = schema.getLogicalType();
diff --git a/lang/java/avro/src/main/java/org/apache/avro/io/DatumWriter.java b/lang/java/avro/src/main/java/org/apache/avro/io/DatumWriter.java
index f1e57626912..4c2749e2bef 100644
--- a/lang/java/avro/src/main/java/org/apache/avro/io/DatumWriter.java
+++ b/lang/java/avro/src/main/java/org/apache/avro/io/DatumWriter.java
@@ -36,4 +36,11 @@ public interface DatumWriter<D> {
    * the schema from the datum to the output.
    */
   void write(D datum, Encoder out) throws IOException;
+
+  /**
+   * Convenience method to Write a datum to a byte array. Traverse the schema,
+   * depth first, writing each leaf value in the schema from the datum to the byte
+   * array.
+   */
+  byte[] toByteArray(D datum) throws IOException;
 }
diff --git a/lang/java/avro/src/main/java/org/apache/avro/specific/SpecificData.java b/lang/java/avro/src/main/java/org/apache/avro/specific/SpecificData.java
index c7b5eaed8a7..4a82b212d49 100644
--- a/lang/java/avro/src/main/java/org/apache/avro/specific/SpecificData.java
+++ b/lang/java/avro/src/main/java/org/apache/avro/specific/SpecificData.java
@@ -49,8 +49,6 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.WeakHashMap;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
 import java.util.function.Function;
 
 /** Utilities for generated Java classes and interfaces. */
@@ -257,7 +255,9 @@ protected Schema getEnumSchema(Object datum) {
     return (datum instanceof Enum) ? getSchema(datum.getClass()) : super.getEnumSchema(datum);
   }
 
-  private final ConcurrentMap<String, Class> classCache = new ConcurrentHashMap<>();
+  // private final ConcurrentMap<String, Class> classCache = new
+  // ConcurrentHashMap<>();
+  private final ThreadLocal<Map<String, Class<?>>> classCache = ThreadLocal.withInitial(HashMap::new);
 
   private static final Class NO_CLASS = new Object() {
   }.getClass();
@@ -363,7 +363,7 @@ public Class getClass(Schema schema) {
       String name = schema.getFullName();
       if (name == null)
         return null;
-      Class<?> c = classCache.computeIfAbsent(name, n -> {
+      Class<?> c = classCache.get().computeIfAbsent(name, n -> {
         try {
           return ClassUtils.forName(getClassLoader(), getClassName(schema));
         } catch (ClassNotFoundException e) {
diff --git a/lang/java/avro/src/test/java/org/apache/avro/specific/TestSpecificData.java b/lang/java/avro/src/test/java/org/apache/avro/specific/TestSpecificData.java
index 5c8cad85331..1d9d58b0518 100644
--- a/lang/java/avro/src/test/java/org/apache/avro/specific/TestSpecificData.java
+++ b/lang/java/avro/src/test/java/org/apache/avro/specific/TestSpecificData.java
@@ -179,6 +179,20 @@ void nonStringable() throws Exception {
     }
   }
 
+  @Test
+  void testToByteArray() throws Exception {
+    final Schema string = Schema.create(Type.STRING);
+    final DatumWriter<String> writer = new SpecificDatumWriter<>(string);
+
+    try (final ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+      final Encoder encoder = EncoderFactory.get().directBinaryEncoder(baos, null);
+      writer.write("test", encoder);
+
+      final byte[] bytes = writer.toByteArray("test");
+      assertArrayEquals(baos.toByteArray(), bytes);
+    }
+  }
+
   @Test
   void classNameContainingReservedWords() {
     final Schema schema = Schema.createRecord("AnyName", null, "db.public.table", false);