[PATCH] AbstractStringBuilder.append(<StringBuilder>)

[Martin Buchholz]

I'm fairly sure the append(StringBuilder) overloads were left out
intentionally.

On Wed, Jun 27, 2018 at 8:57 PM, Isaac Levy <isaac.r.levy at gmail.com> wrote:

> AbstractStringBuilder already has append(<StringBuffer>). This patch
> adds append(<StringBuilder>).
>
> The new method improves parity between the two classes. In addition,
> combining StringBuilders is presumably common. append(<CharSequence>)
> has a couple insteadof checks, which this new method skips.
>
> -Isaac
>
>
>
>
> diff --git a/src/java.base/share/classes/java/lang/
> AbstractStringBuilder.java
> b/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
> index 2ef3e53256..1fe89bb92a 100644
> --- a/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
> +++ b/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
> @@ -543,6 +543,11 @@ abstract class AbstractStringBuilder implements
> Appendable, CharSequence {
>          return this.append((AbstractStringBuilder)sb);
>      }
>
> +    // Documentation in subclasses because of synchro difference
> +    public AbstractStringBuilder append(StringBuilder sb) {
> +        return this.append((AbstractStringBuilder)sb);
> +    }
> +
>      /**
>       * @since 1.8
>       */
> diff --git a/src/java.base/share/classes/java/lang/StringBuffer.java
> b/src/java.base/share/classes/java/lang/StringBuffer.java
> index e597a8112e..613ba90c25 100644
> --- a/src/java.base/share/classes/java/lang/StringBuffer.java
> +++ b/src/java.base/share/classes/java/lang/StringBuffer.java
> @@ -313,6 +313,33 @@ import jdk.internal.HotSpotIntrinsicCandidate;
>          return this;
>      }
>
> +    /**
> +     * Appends the specified {@code StringBuilder} to this sequence.
> +     * <p>
> +     * The characters of the {@code StringBuilder} argument are appended,
> +     * in order, to the contents of this {@code StringBuffer}, increasing
> the
> +     * length of this {@code StringBuffer} by the length of the argument.
> +     * If {@code sb} is {@code null}, then the four characters
> +     * {@code "null"} are appended to this {@code StringBuffer}.
> +     * <p>
> +     * Let <i>n</i> be the length of the old character sequence, the one
> +     * contained in the {@code StringBuffer} just prior to execution of
> the
> +     * {@code append} method. Then the character at index <i>k</i> in
> +     * the new character sequence is equal to the character at index
> <i>k</i>
> +     * in the old character sequence, if <i>k</i> is less than <i>n</i>;
> +     * otherwise, it is equal to the character at index <i>k-n</i> in the
> +     * argument {@code sb}.
> +     * <p>
> +     *
> +     * @param   sb   the {@code StringBuilder} to append.
> +     * @return  a reference to this object.
> +     */
> +    public synchronized StringBuffer append(StringBuilder sb) {
> +        toStringCache = null;
> +        super.append(sb);
> +        return this;
> +    }
> +
>      /**
>       * Appends the specified {@code StringBuffer} to this sequence.
>       * <p>
> diff --git a/src/java.base/share/classes/java/lang/StringBuilder.java
> b/src/java.base/share/classes/java/lang/StringBuilder.java
> index 40da2083c2..5ddd4fb5f9 100644
> --- a/src/java.base/share/classes/java/lang/StringBuilder.java
> +++ b/src/java.base/share/classes/java/lang/StringBuilder.java
> @@ -199,6 +199,30 @@ public final class StringBuilder
>          return this;
>      }
>
> +    /**
> +     * Appends the specified {@code StringBuilder} to this sequence.
> +     * <p>
> +     * The characters of the {@code StringBuilder} argument are appended,
> +     * in order, to this sequence, increasing the
> +     * length of this sequence by the length of the argument.
> +     * If {@code sb} is {@code null}, then the four characters
> +     * {@code "null"} are appended to this sequence.
> +     * <p>
> +     * Let <i>n</i> be the length of this character sequence just prior to
> +     * execution of the {@code append} method. Then the character at index
> +     * <i>k</i> in the new character sequence is equal to the character at
> +     * index <i>k</i> in the old character sequence, if <i>k</i> is less
> than
> +     * <i>n</i>; otherwise, it is equal to the character at index
> <i>k-n</i>
> +     * in the argument {@code sb}.
> +     *
> +     * @param   sb   the {@code StringBuilder} to append.
> +     * @return  a reference to this object.
> +     */
> +    public StringBuilder append(StringBuilder sb) {
> +        super.append(sb);
> +        return this;
> +    }
> +
>      @Override
>      public StringBuilder append(CharSequence s) {
>          super.append(s);
>