MulticastSendReceiveTests.java should ignore interference on the network. When the received bytes are not parseable into an Integer, expected id, the packet should be ignored and the test should continue. Additionally, the test should attempt to reconstruct the String message with the same charset as is used to convert the original message to bytes, UTF-8.

The following exception was seen during testing (because of this bug):

java.lang.NumberFormatException: For input string: "\u0001\u0002\u0003\u0005"
       at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
       at java.lang.Integer.parseInt(Integer.java:567)
       at java.lang.Integer.parseInt(Integer.java:699)
       at MulticastSendReceiveTests.receiveDatagram(MulticastSendReceiveTests.java:112)
       at MulticastSendReceiveTests.test(MulticastSendReceiveTests.java:182)
       at MulticastSendReceiveTests.main(MulticastSendReceiveTests.java:245)
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
       at java.lang.reflect.Method.invoke(Method.java:502)
       at com.sun.javatest.regtest.MainAction$SameVMRunnable.run(MainAction.java:776)
       at java.lang.Thread.run(Thread.java:745)

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Proposed changes:

diff --git a/test/java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java b/test/java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java
--- a/test/java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java
+++ b/test/java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java
                buf.flip();
                byte[] bytes = new byte[buf.remaining()];
                buf.get(bytes);
- int receivedId = Integer.parseInt(new String(bytes));
-
- System.out.format("Received message from %s (id=0x%x)\n",
- sender, receivedId);
+ String s = new String(bytes, "UTF-8");
+ int receivedId = -1;
+ try {
+ receivedId = Integer.parseInt(s);
+ System.out.format("Received message from %s (id=0x%x)\n",
+ sender, receivedId);
+ } catch (NumberFormatException x) {
+ System.out.format("Received message from %s (msg=%s)\n", sender, s);
+ }

                if (expectedSender == null) {
                    if (receivedId == id)