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

rev 48083 : [mq]: 4358774-nullISAndOS.01
rev 48082 : 4358774: Add null InputStream and OutputStream
Reviewed-by: XXX
rev 47920 : 8191516: OutputStream.write(byte[],int,int) could have fewer parameter bounds checks
Summary: Reduce parameter bounds checks from five to three as in InputStream::read
Reviewed-by: psandoz
rev 47216 : 8187443: Forest Consolidation: Move files to unified layout
Reviewed-by: darcy, ihse

*** 45,54 ****
--- 45,99 ----
   * @see     java.io.OutputStream#write(int)
   * @since   1.0
   */
  public abstract class OutputStream implements Closeable, Flushable {
      /**
+      * Returns a new {@code OutputStream} which discards all bytes.  The
+      * returned stream is initially open.  The stream is closed by calling
+      * the {@code close()} method.  Subsequent calls to {@code close()} have
+      * no effect.
+      *
+      * <p> While the stream is open, the {@code write(int)}, {@code
+      * write(byte[])}, and {@code write(byte[], int, int)} methods do nothing.
+      * After the stream has been closed, these methods all throw {@code
+      * IOException}.
+      *
+      * <p> The {@code flush()} method does nothing.
+      *
+      * @return an {@code OutputStream} which discards all bytes
+      *
+      * @since 10
+      */
+     public static OutputStream nullStream() {
+         return new OutputStream() {
+             private volatile boolean closed;
+ 
+             @Override
+             public void write(int b) throws IOException {
+                 if (closed) {
+                     throw new IOException("Stream closed");
+                 }
+             }
+ 
+             @Override
+             // overridden for efficiency
+             public void write(byte b[], int off, int len) throws IOException {
+                 Objects.requireNonNull(b);
+                 Objects.checkFromIndexSize(off, len, b.length);
+                 if (closed) {
+                     throw new IOException("Stream closed");
+                 }
+             }
+ 
+             @Override
+             public void close() {
+                 closed = true;
+             }
+         };
+     }
+ 
+     /**
       * Writes the specified byte to this output stream. The general
       * contract for <code>write</code> is that one byte is written
       * to the output stream. The byte to be written is the eight
       * low-order bits of the argument <code>b</code>. The 24
       * high-order bits of <code>b</code> are ignored.