Summary

Change java.lang.classfile.Attribute::attributeName method return type from String to java.lang.classfile.constantpool.Utf8Entry.

Problem

Class-File API usually expose names in a form of java.lang.classfile.constantpool.Utf8Entry. Unfortunately java.lang.classfile.Attribute::attributeName method was omitted during the API review and it returns inflated String value of the name.

Solution

Change java.lang.classfile.Attribute::attributeName method return type from String to java.lang.classfile.constantpool.Utf8Entry.

Specification

diff --git a/src/java.base/share/classes/java/lang/classfile/Attribute.java b/src/java.base/share/classes/java/lang/classfile/Attribute.java
index e2f0072d3967f..2d559552684a1 100644
--- a/src/java.base/share/classes/java/lang/classfile/Attribute.java
+++ b/src/java.base/share/classes/java/lang/classfile/Attribute.java
@@ -25,6 +25,7 @@
 package java.lang.classfile;

 import java.lang.classfile.attribute.*;
+import java.lang.classfile.constantpool.Utf8Entry;

 import jdk.internal.classfile.impl.BoundAttribute;
 import jdk.internal.classfile.impl.UnboundAttribute;
@@ -65,7 +66,7 @@ public sealed interface Attribute<A extends Attribute<A>>
     /**
      * {@return the name of the attribute}
      */
-    String attributeName();
+    Utf8Entry attributeName();

     /**
      * {@return the {@link AttributeMapper} associated with this attribute}
diff --git a/src/java.base/share/classes/java/lang/classfile/CustomAttribute.java b/src/java.base/share/classes/java/lang/classfile/CustomAttribute.java
index 9fe492dc22c4c..6c3a0de2b7af3 100644
--- a/src/java.base/share/classes/java/lang/classfile/CustomAttribute.java
+++ b/src/java.base/share/classes/java/lang/classfile/CustomAttribute.java
@@ -24,6 +24,8 @@
  */
 package java.lang.classfile;

+import java.lang.classfile.constantpool.Utf8Entry;
+import jdk.internal.classfile.impl.TemporaryConstantPool;
 import jdk.internal.javac.PreviewFeature;

 /**
@@ -55,8 +57,8 @@ public final AttributeMapper<T> attributeMapper() {
     }

     @Override
-    public final String attributeName() {
-        return mapper.name();
+    public Utf8Entry attributeName() {
+        return TemporaryConstantPool.INSTANCE.utf8Entry(mapper.name());
     }

     @Override