Re: [PATCH] JDK-8054565: FilterOutputStream.close may throw IOException if called twice and underlying flush or close fails

[Chris Hegarty]

On 05/12/14 15:33, Alan Bateman wrote:
On 05/12/2014 14:04, Chris Hegarty wrote:
 ...
Right, no need for it to be protected. I think what you have seems right
but we probably need a small spec clarification so that it reads "When
not already closed, the close method of FilterOutputStream ...". That
removes the testable assertion that flush that is always called.

Right. Just to close the loop, the change, excluding testcase, looks like:

diff --git a/src/java.base/share/classes/java/io/FilterOutputStream.java 
b/src/java.base/share/classes/java/io/FilterOutputStream.java
--- a/src/java.base/share/classes/java/io/FilterOutputStream.java
+++ b/src/java.base/share/classes/java/io/FilterOutputStream.java
@@ -48,6 +48,8 @@
      */
     protected OutputStream out;

+    private boolean closed;
+
     /**
      * Creates an output stream filter built on top of the specified
      * underlying output stream.
@@ -144,9 +146,9 @@
      * Closes this output stream and releases any system resources
      * associated with the stream.
      * <p>
-     * The <code>close</code> method of <code>FilterOutputStream</code>
-     * calls its <code>flush</code> method, and then calls the
-     * <code>close</code> method of its underlying output stream.
+     * When not already closed, the {@code close} method of {@code
+     * FilterOutputStream} calls its {@code flush} method, and then
+     * calls the {@code close} method of its underlying output stream.
      *
      * @exception  IOException  if an I/O error occurs.
      * @see        java.io.FilterOutputStream#flush()
@@ -154,6 +156,9 @@
      */
     @SuppressWarnings("try")
     public void close() throws IOException {
+        if (closed)
+            return;
+        closed = true;
         try (OutputStream ostream = out) {
             flush();
         }

-Chris.