Hi David,
Good idea, but I did not use that method because of all the String
concatenation PrintStream.print has to perform, if so then we can
simply use a String.
So my thinking was to use the StringBuilder to assemble the String and
print it out in one shot.
ostream(INDENT + INDENT);
or instead:
ostream.print(INDENT);
ostream.print(INDENT);
...
....
that would mean more io calls.
I have a time pressure to get this in, I can fix/address this later as a bug
if need be.
Thanks for your review.
Kumar
Kumar,
Do you need all of the StringBuilder/StringBuffer to buffer the output
prior to writing to the PrintStream? Using the PrintStream directly
would also allow it to handle the newlines. I was envisaging something
like this:
private static void printVmSettings(PrintStream ostream, long maxHeapSize,
long stackSize, boolean isServer) {
String maxHeapSizeString = scaleValue((maxHeapSize == 0)
? Runtime.getRuntime().maxMemory()
: maxHeapSize);
String stackSizeString = (stackSize == 0)
? "OS default"
: scaleValue(stackSize);
ostream.println();
ostream.println(VM_SETTINGS);
ostream.print(INDENT + "Stack Size (-Xss): ");
ostream.println(stackSizeString);
ostream.print(INDENT + "Max. Heap Size (-Xmx): ");
ostream.println(maxHeapSizeString);
ostream.print(INDENT + "Ergonomics Class (server or client): ");
ostream.println((isServer) ? "server" : "client");
ostream.print(INDENT + "Using VM: ");
ostream.println(System.getProperty("java.vm.name"));
}
private static boolean isPath(String key) {
return key.endsWith(".dirs") || key.endsWith(".path");
}
private static void prettyPrintValue(PrintStream ostream, String key,
String value) {
ostream.print(INDENT);
ostream.print(key);
ostream.print(" = ");
if (!isPath(key)) {
ostream.println(value);
return;
}
// pretty print the path values as a list
String pathsep = System.getProperty("path.separator");
String[] values = value.split(pathsep);
int len = values.length;
int lastline = len - 1;
for (int i = 0 ; i< len ; i++) {
if (i == 0) { // first line treated specially
ostream.print(values[i]);
ostream.println(pathsep);
} else { // following lines prefix with indents
ostream.print(INDENT + INDENT);
ostream.print(values[i]);
if (i != lastline) { // if not the last line suffix the pathsep
ostream.print(pathsep);
}
ostream.println();
}
}
}
private static void printProperties(PrintStream ostream) {
Properties p = System.getProperties();
List<String> sortedPropertyKeys = new ArrayList<>();
sortedPropertyKeys.addAll(p.stringPropertyNames());
Collections.sort(sortedPropertyKeys);
ostream.println();
ostream.println(PROP_SETTINGS);
for (String x : sortedPropertyKeys) {
prettyPrintValue(ostream, x, p.getProperty(x));
}
}
private static void prettyPrintLocales(PrintStream ostream) {
ostream.println();
ostream.print(INDENT + "available locales = ");
Locale[] locales = Locale.getAvailableLocales();
int len = locales.length;
int lastline = len - 1 ;
for (int i = 0 ; i< len ; i++) {
ostream.print(locales[i]);
if (i != lastline) {
ostream.print(",");
}
// print columns of 8
if ((i + 1) % 8 == 0) {
ostream.println();
ostream.print(INDENT + INDENT);
} else {
ostream.print(" ");
}
}
}
private static void printLocale(PrintStream ostream) {
Locale locale = Locale.getDefault();
ostream.println();
ostream.println(LOCALE_SETTINGS);
ostream.print(INDENT+"default locale: ");
ostream.print(locale.getDisplayLanguage());
prettyPrintLocales(ostream);
ostream.println();
}
- Dave
On Thu, Nov 11, 2010 at 7:42 PM, Kumar Srinivasan
<kumar.x.sriniva...@oracle.com> wrote:
Hi Mandy,
java.c
line 1031: this doesn't catch invalid option if it has the -XshowSettings
prefix e.g. -XshowSettingsJunk.
Will fix it.
line 1032: Perhaps you could store the suboption ("all", "vm", etc) rather than
the entire option string.
I want to keep all the parsing logic as much as possible in java.
line 1507-1511: should these lines align with the argument "env" to
CallStaticVoidMethod method in line 1506?
Fixed.
LauncherHelper.java
line 106-109: if optionFlag is just the suboption to -XshowSettings, these
lines can be removed.
line 150-152: Runtime.maxMemory() is not equivalent to -Xmx value. Perhaps
-XshowSettings always prints Runtime.maxMemory() and print -Xmx if set in the
command line?
That is exactly what is happening ie. if the launcher has been given the -Xmx
flag
then that is displayed, if not LauncherHelper will use some means to display any
value it can get from Java libraries so for now we use Runtime.maxMemory().
line 176, 188, 190-191, 195, and other lines in printPrintLocales and
printLocale methods:
- the assignment to the buf and out variable to itself (returned from
StringBuffer.append() method) is not necessary.
Yes fixed, I missed these.
line 174: would it be better to pass the StringBuilder to the printPrintValue
method so that it can avoid creating a new StringBuilder instance for each
property?
We have to create the StringBuilder somewhere it is either in the
prettyPrintValue or the calling
method, I will convert it to StringBuilder and pass it into prettyPrintValue.
line 213-214: same comment as the above. And should it use StringBuilder
instead?
Yes.
Thanks for the review.!
Kumar
Mandy
This will print all the known settings/properties/locales
supported and known to Java, this has been a long standing request.
A sample output attached below.
Note: the -X option specifically is being used so we can evolve this option
and add more useful information, in future versions of java.
Thanks
Kumar
