An alternative, more compact variant might be
------------------------
String getErrorMessage(InputStream sis, int maxlen) throws
IOException {
int n, off = 0, len = maxlen + 1;
byte b[] = new byte[len];
while ((n = sis.read(b, off, len - off)) > 0)
off += n;
return (off == 0) ? null
: (off < len)
? new String(b, 0, off, "UTF-8")
: new String(b, 0, maxlen, "UTF-8") + " ...";
}
------------------------
Not a big deal, of course.
Sincerely yours,
Ivan
On 04.04.2014 16:24, Ivan Gerasimov wrote:
Now you reintroduced the smallish issue, when the message is exactly
200 characters (or whatever maxlen is).
The dots will be appended to the message, even though it's not necessary.
I think the only reliable way to deal with it is to try to read one
extra character from sis.
Something like this should do:
------------------------
String getErrorMessage(InputStream sis, int maxlen) throws
IOException {
byte b[] = new byte[maxlen + 1];
int n, off = 0, len = b.length;
do {
n = sis.read(b, off, len);
if (n == -1) {
break;
}
off += n;
len -= n;
} while (off < maxlen);
String message = null;
if (off > 0) {
message = (off > maxlen)
? new String(b, 0, maxlen, "UTF-8") + " ..."
: new String(b, 0, off, "UTF-8");
}
return message;
}
------------------------
Sincerely yours,
Ivan
On 04.04.2014 16:08, Staffan Larsen wrote:
I’m afraid you are right! Doh. Need to add more testing...
How about this change:
--- a/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
+++ b/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
@@ -267,9 +267,11 @@
String getErrorMessage(InputStream sis, int maxlen) throws
IOException {
byte b[] = new byte[maxlen];
int n, off = 0, len = maxlen;
+ boolean complete = false;
do {
n = sis.read(b, off, len);
if (n == -1) {
+ complete = true;
break;
}
off += n;
@@ -280,7 +282,7 @@
if (off > 0) {
message = new String(b, 0, off, "UTF-8");
}
- if (off > b.length && message != null) {
+ if (!complete && message != null) {
message += " ...";
}
return message;
On 4 apr 2014, at 13:55, Ivan Gerasimov <ivan.gerasi...@oracle.com>
wrote:
Thank you Staffan for fixing them!
But I'm afraid that now the function will never add ellipsis to the
message, even if it gets truncated.
Sincerely yours,
Ivan
On 04.04.2014 15:47, Staffan Larsen wrote:
Thanks for finding these bugs, Ivan!
I have updated the webrev at:
http://cr.openjdk.java.net/~sla/8039173/webrev.01/, and I have also
included the diff below.
The updated webrev also has some changes in the javadoc for
VirtualMachine to clarify that some methods can now throw
AttachOperationFailedException.
Thanks,
/Staffan
diff --git
a/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
b/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
--- a/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
+++ b/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
@@ -266,18 +266,21 @@
*/
String getErrorMessage(InputStream sis, int maxlen) throws
IOException {
byte b[] = new byte[maxlen];
- int n, off = 0, len = b.length;
+ int n, off = 0, len = maxlen;
do {
n = sis.read(b, off, len);
+ if (n == -1) {
+ break;
+ }
off += n;
len -= n;
- } while (n >= 0 && off < b.length);
+ } while (off < maxlen);
String message = null;
if (off > 0) {
message = new String(b, 0, off, "UTF-8");
}
- if (off == b.length && message != null) {
+ if (off > b.length && message != null) {
message += " ...";
}
return message;
On 4 apr 2014, at 11:18, Ivan Gerasimov <ivan.gerasi...@oracle.com>
wrote:
Hi Staffan!
I think there is a couple of minor bugs in
getErrorMessage(InputStream sis, int maxlen).
1) If maxlen is exactly the size of the message to read, the
function will add an ellipsis, even though the message isn't
truncated,
2) If maxlen is greater than needed, then sis.read(b, off, len) at
the line #271 will eventually return -1, and it will cause the
message to lose its last character.
Sincerely yours,
Ivan
