diff --git a/lang/java/avro/src/test/java/org/apache/avro/specific/TestRecordWithoutLogicalTypes.java b/lang/java/avro/src/test/java/org/apache/avro/specific/TestRecordWithoutLogicalTypes.java
index f53f1537ffd..c5d9c191c1f 100644
--- a/lang/java/avro/src/test/java/org/apache/avro/specific/TestRecordWithoutLogicalTypes.java
+++ b/lang/java/avro/src/test/java/org/apache/avro/specific/TestRecordWithoutLogicalTypes.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/avro/src/test/java/org/apache/avro/specific/int$.java b/lang/java/avro/src/test/java/org/apache/avro/specific/int$.java
index 586d4219124..17c2bef4770 100644
--- a/lang/java/avro/src/test/java/org/apache/avro/specific/int$.java
+++ b/lang/java/avro/src/test/java/org/apache/avro/specific/int$.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
@@ -28,7 +28,7 @@ public static org.apache.avro.Schema getClassSchema() {
 
   /**
    * Return the BinaryMessageEncoder instance used by this class.
-   * 
+   *
    * @return the message encoder used by this class
    */
   public static BinaryMessageEncoder<int$> getEncoder() {
@@ -37,7 +37,7 @@ public static org.apache.avro.Schema getClassSchema() {
 
   /**
    * Return the BinaryMessageDecoder instance used by this class.
-   * 
+   *
    * @return the message decoder used by this class
    */
   public static BinaryMessageDecoder<int$> getDecoder() {
@@ -47,7 +47,7 @@ public static org.apache.avro.Schema getClassSchema() {
   /**
    * Create a new BinaryMessageDecoder instance for this class that uses the
    * specified {@link SchemaStore}.
-   * 
+   *
    * @param resolver a {@link SchemaStore} used to find schemas by fingerprint
    * @return a BinaryMessageDecoder instance for this class backed by the given
    *         SchemaStore
@@ -58,7 +58,7 @@ public static org.apache.avro.Schema getClassSchema() {
 
   /**
    * Serializes this int to a ByteBuffer.
-   * 
+   *
    * @return a buffer holding the serialized data for this instance
    * @throws java.io.IOException if this instance could not be serialized
    */
@@ -68,7 +68,7 @@ public java.nio.ByteBuffer toByteBuffer() throws java.io.IOException {
 
   /**
    * Deserializes a int from a ByteBuffer.
-   * 
+   *
    * @param b a byte buffer holding serialized data for an instance of this class
    * @return a int instance decoded from the given buffer
    * @throws java.io.IOException if the given bytes could not be deserialized into
@@ -105,7 +105,7 @@ public void put(int field$, Object value$) {
 
   /**
    * Creates a new int$ RecordBuilder.
-   * 
+   *
    * @return A new int$ RecordBuilder
    */
   public static Builder newBuilder() {
@@ -114,7 +114,7 @@ public static Builder newBuilder() {
 
   /**
    * Creates a new int$ RecordBuilder by copying an existing Builder.
-   * 
+   *
    * @param other The existing builder to copy.
    * @return A new int$ RecordBuilder
    */
@@ -128,7 +128,7 @@ public static Builder newBuilder(Builder other) {
 
   /**
    * Creates a new int$ RecordBuilder by copying an existing int$ instance.
-   * 
+   *
    * @param other The existing instance to copy.
    * @return A new int$ RecordBuilder
    */
@@ -154,7 +154,7 @@ private Builder() {
 
     /**
      * Creates a Builder by copying an existing Builder.
-     * 
+     *
      * @param other The existing Builder to copy.
      */
     private Builder(Builder other) {
@@ -163,7 +163,7 @@ private Builder(Builder other) {
 
     /**
      * Creates a Builder by copying an existing int$ instance
-     * 
+     *
      * @param other The existing instance to copy.
      */
     private Builder(int$ other) {
diff --git a/lang/java/compiler/src/main/java/org/apache/avro/compiler/specific/SpecificCompiler.java b/lang/java/compiler/src/main/java/org/apache/avro/compiler/specific/SpecificCompiler.java
index 31a4a495bfd..bf1b63e98f8 100644
--- a/lang/java/compiler/src/main/java/org/apache/avro/compiler/specific/SpecificCompiler.java
+++ b/lang/java/compiler/src/main/java/org/apache/avro/compiler/specific/SpecificCompiler.java
@@ -145,8 +145,7 @@ public boolean isCreateAllArgsConstructor() {
     return createAllArgsConstructor;
   }
 
-  private static final String FILE_HEADER = "/**\n" + " * Autogenerated by Avro\n" + " *\n"
-      + " * DO NOT EDIT DIRECTLY\n" + " */\n";
+  private static final String FILE_HEADER = "/*\n * Autogenerated by Avro\n *\n * DO NOT EDIT DIRECTLY\n */\n";
 
   public SpecificCompiler(Protocol protocol) {
     this();
diff --git a/lang/java/compiler/src/test/java/org/apache/avro/compiler/specific/TestSpecificCompiler.java b/lang/java/compiler/src/test/java/org/apache/avro/compiler/specific/TestSpecificCompiler.java
index 1916ab43c4d..f42989cfefd 100644
--- a/lang/java/compiler/src/test/java/org/apache/avro/compiler/specific/TestSpecificCompiler.java
+++ b/lang/java/compiler/src/test/java/org/apache/avro/compiler/specific/TestSpecificCompiler.java
@@ -133,7 +133,7 @@ static void assertCompilesWithJavaCompiler(File dstDir, Collection<SpecificCompi
     boolean compilesWithoutError = cTask.call();
     assertTrue(compilesWithoutError);
     if (!ignoreWarnings) {
-      assertEquals(0, warnings.size(), "Warnings produced when compiling generated code with -Xlint:all");
+      assertEquals(List.of(), warnings, "Warnings produced when compiling generated code with -Xlint:all");
     }
   }
 
diff --git a/lang/java/tools/src/test/compiler/output-string/Position.java b/lang/java/tools/src/test/compiler/output-string/Position.java
index a4504bbc4c9..120f6209414 100644
--- a/lang/java/tools/src/test/compiler/output-string/Position.java
+++ b/lang/java/tools/src/test/compiler/output-string/Position.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/FieldTest.java b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/FieldTest.java
index 8e567f6de7e..6e69cd3df48 100644
--- a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/FieldTest.java
+++ b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/FieldTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JSpecifyNullSafeAnnotationsFieldsTest.java b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JSpecifyNullSafeAnnotationsFieldsTest.java
index 1fa56857f8f..7a352b703d3 100644
--- a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JSpecifyNullSafeAnnotationsFieldsTest.java
+++ b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JSpecifyNullSafeAnnotationsFieldsTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JetBrainsNullSafeAnnotationsFieldsTest.java b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JetBrainsNullSafeAnnotationsFieldsTest.java
index 44db6edcae1..5e898c8847c 100644
--- a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JetBrainsNullSafeAnnotationsFieldsTest.java
+++ b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JetBrainsNullSafeAnnotationsFieldsTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Player.java b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Player.java
index c472f589565..1821e41cbe8 100644
--- a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Player.java
+++ b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Player.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Position.java b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Position.java
index 3e6abc502ae..b662bcac5a7 100644
--- a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Position.java
+++ b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Position.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Proto.java b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Proto.java
index 20463106a1c..def7bca42b6 100644
--- a/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Proto.java
+++ b/lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Proto.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
@@ -24,4 +24,4 @@ public interface Callback extends Proto {
      */
     void bar(org.apache.avro.ipc.Callback<java.lang.Void> callback) throws java.io.IOException;
   }
-}
\ No newline at end of file
+}
diff --git a/lang/java/tools/src/test/compiler/output/AddExtraOptionalGettersTest.java b/lang/java/tools/src/test/compiler/output/AddExtraOptionalGettersTest.java
index 0d5fd94ea73..d8c53618488 100644
--- a/lang/java/tools/src/test/compiler/output/AddExtraOptionalGettersTest.java
+++ b/lang/java/tools/src/test/compiler/output/AddExtraOptionalGettersTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output/NoSettersTest.java b/lang/java/tools/src/test/compiler/output/NoSettersTest.java
index 4f6914dcff0..6e4cea44f8e 100644
--- a/lang/java/tools/src/test/compiler/output/NoSettersTest.java
+++ b/lang/java/tools/src/test/compiler/output/NoSettersTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output/OptionalGettersAllFieldsTest.java b/lang/java/tools/src/test/compiler/output/OptionalGettersAllFieldsTest.java
index 10453c307e5..ece62933a80 100644
--- a/lang/java/tools/src/test/compiler/output/OptionalGettersAllFieldsTest.java
+++ b/lang/java/tools/src/test/compiler/output/OptionalGettersAllFieldsTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output/OptionalGettersNullableFieldsTest.java b/lang/java/tools/src/test/compiler/output/OptionalGettersNullableFieldsTest.java
index aa55db60075..60c87c2953c 100644
--- a/lang/java/tools/src/test/compiler/output/OptionalGettersNullableFieldsTest.java
+++ b/lang/java/tools/src/test/compiler/output/OptionalGettersNullableFieldsTest.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output/Player.java b/lang/java/tools/src/test/compiler/output/Player.java
index 3fbfd1cfe88..e1f6f91c84d 100644
--- a/lang/java/tools/src/test/compiler/output/Player.java
+++ b/lang/java/tools/src/test/compiler/output/Player.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY
diff --git a/lang/java/tools/src/test/compiler/output/Position.java b/lang/java/tools/src/test/compiler/output/Position.java
index 3e6abc502ae..b662bcac5a7 100644
--- a/lang/java/tools/src/test/compiler/output/Position.java
+++ b/lang/java/tools/src/test/compiler/output/Position.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Autogenerated by Avro
  *
  * DO NOT EDIT DIRECTLY