java.io.StringWriter utilizes java.lang.CharSequence.getChars

Author: mkarg

src/java.base/share/classes/java/io/StringWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -125,20 +125,6 @@ public void write(String str, int off, int len)  {
     /**
      * Appends the specified character sequence to this writer.
      *
-     * <p> An invocation of this method of the form {@code out.append(csq)}
-     * when {@code csq} is not {@code null}, behaves in exactly the same way
-     * as the invocation
-     *
-     * {@snippet lang=java :
-     *     out.write(csq.toString())
-     * }
-     *
-     * <p> Depending on the specification of {@code toString} for the
-     * character sequence {@code csq}, the entire sequence may not be
-     * appended. For instance, invoking the {@code toString} method of a
-     * character buffer will return a subsequence whose content depends upon
-     * the buffer's position and limit.
-     *
      * @param  csq
      *         The character sequence to append.  If {@code csq} is
      *         {@code null}, then the four characters {@code "null"} are
@@ -149,22 +135,14 @@ public void write(String str, int off, int len)  {
      * @since  1.5
      */
     public StringWriter append(CharSequence csq) {
-        write(String.valueOf(csq));
+        if (csq == null) csq = "null";
+        buf.append(csq);
         return this;
     }
 
     /**
      * Appends a subsequence of the specified character sequence to this writer.
      *
-     * <p> An invocation of this method of the form
-     * {@code out.append(csq, start, end)} when {@code csq}
-     * is not {@code null}, behaves in
-     * exactly the same way as the invocation
-     *
-     * {@snippet lang=java :
-     *     out.write(csq.subSequence(start, end).toString())
-     * }
-     *
      * @param  csq
      *         The character sequence from which a subsequence will be
      *         appended.  If {@code csq} is {@code null}, then characters
@@ -189,7 +167,8 @@ public StringWriter append(CharSequence csq) {
      */
     public StringWriter append(CharSequence csq, int start, int end) {
         if (csq == null) csq = "null";
-        return append(csq.subSequence(start, end));
+        buf.append(csq, start, end);
+        return this;
     }
 
     /**