One Char String - performance

Hi-ya all
Two questions, both performance related.
1. What would be the fastest way to produce a one char string, is there anything faster than new String(char + "").
2. What would be the fastest way to get an uppercase from a char, is there anything better than a switch and or set of if/elses, for example some sort of fiddle factor?
thanks

Character.toString(char)
Character.toUpperCase(char)

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Making one big String with the same char

I need to generate a String which represents only one char n-times.
Something like:
String str = new String(char Source, int iRepeat)
String str = new String('x', 5);
str = 'xxxxx';
Thanks in advance!

public String createString(char c, int n) {
StringBuffer sb = new StringBuffer();
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sb.append(c);
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always use string buffers when youre appending text. when you change the value of a STRING object, the jvm actually creates a new string in memory, and just changes the reference to the new string (since each variable you declare as STRING is actually just a reference). this isnt a problem with small strings, but if you create a string thats fairly large, youll notice a huge performance difference. so, just use Strings for storing values, and StringBuffers for string values you plan on changing often.

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I know this:
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When you have more than one char, you probably have them in an array. In that case you can use the String(char[]) constructor.char[] hello = new char[5];
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I'm developing an small app. In certain cases, the user may want to edit a little piece of text. For this, I show a new Frame with a JTextArea with the selected text, so the user can edit it...
But I want to control this edition: the user only can type one char at a time, disable selecting text and waiting a short time (250ms) between char and char...
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Use a DocumentFilter and add the character yourself one at a time.
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Generate unique 10 char string

Hi,
i have to generate a unique 10 char string ( a string with length of 10 ) which has numbers and alphabets with no special characters, is there any code of doing it
Ashish

class UniqueString {
private static final int NUM_CHARS = 10;
private static int[] lastString = new int[NUM_CHARS];
private static final String chars =
"0123456789abcdefghijklmonpqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
static String getUnique() {
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How can I get an unsigned char string with nulls from a dll into LabVIEW 6i?

The following ethernet packet data is contained in an unsigned char * string returned from my dll (it's formatted on printing):
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Ethernet Dest: 01.E0.BB.00.00.15 Src: 00.E0.BB.00.DD.CC Type: 0x8868
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Anybody have any suggestions for how to get the rest of the string? Is there something I can do to further reformat my dll? The dll I'm using is already a wrapper around another dll so I have some flexibility, but the bottom line is, the data I want is in the format of an unsigned char *.

Excellent advice, this mostly works so I have some further questions:
I am just reading network traffic off my ethernet card right now, but here is what I get using my C program to test:
000000: 01 E0 BB 00 00 15 00 E0 : BB 00 DD CC 88 68 48 41 .............hHA
000010: 00 E0 BB 00 DD CC 80 B3 : 00 00 FF FF 00 02 00 01 ................
000020: 01 00 38 3C FF 7F 7F 7F : 7F 7F 7F FF FF 7F 7F FF ..8<............
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000040: FE FF FF FF FF 7F 7F 7F : 7F 7E 7E 7F 7F 7E 7E FF .........~~..~~.
000050: 7F 7F 7F 7F FF 7F 7F 7F : 7F 7F 7F FF FF 7F 7E 7F ..............~.
000060: 7F 7F 7E 7F 7F 7E 7F FF : FF 7F FF FF FE FF FF FE ..~..~..........
000070: FF FF FF FF FF 7F 7F FF : FF 7F 7F FF FF FF FF FF ................
000080: FF 7F 7F FF FF 7F 7F FF : FF 7F 7F FF FF 7F 7F FF ................
000090: FF 7F 7F 7F FF 7F 7F 7F : 7F 7F 7F FF FF 7F 7F FF ................
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0000B0: FF FF 7F FF FF 7F 7F FF : 7F 7F 7F FF FF 7E 7F FF .............~..
0000C0: FF FF 7F FF FF 7F 7F FF : 7F 7F 7F FF FF 7F 7F FF ................
0000D0: FF 7F 7F FF FF 7F 7F 7F : 7F 7F 7F FF FF FF FF FE ................
0000E0: FE FF FF FF 00 01 : ................
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The first thing I notice is that the first 4 bytes are chopped off, and after about 50 bytes, the data is corrupted until the sequence starts to repeat, but this time it starts with the missing 4 bytes and still corrupts after about 55 bytes.
I am expecting the data in LabVIEW to look very similar to the C data because the network packets I am grabbing are pretty consistant, only a couple bytes will vary between them, not the number I am seeing in LabVIEW.
Another side effect I'm seeing is that I can only run my labVIEW code once, if I try running it again it crashes with failures such as:
memory could not be "read"
For reference, I am opening and closing the network adapter inside the read function of my dll, but the pointer seems like it should be intact...
Attachments:
zListAdapters.vi ‏30 KB
listAdapters.dll ‏201 KB
Reading.dll ‏213 KB

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Revision: 20754
Author:   [email protected]
Date:     2011-03-10 03:36:05 -0800 (Thu, 10 Mar 2011)
Log Message:
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[svn:fx-trunk] 11717: Bug Fixing Localized SDK - modified one file xercesSchema. properties in xercesImpl_ja.jar - added " to one JA string.

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Author:   [email protected]
Date:     2009-11-12 11:54:22 -0800 (Thu, 12 Nov 2009)
Log Message:
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Unfortunately I haven't been able to make this work correctly and
was hoping that someone here might be able to help me with this. So
far I have tried the following methods:

Dan, I don't think that I am being clear here (or I have
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that I am trying to overcome right now is having to put each field
into the statement on my results page. Currently the question of
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#paramSelect# equal to field1. If two or more checkboxes are
checked by the user then the value of #paramSelect# becomes a list
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Hi,
Do we have any published document on sun one 8.1 performance and scalability ? or something related to performance tuning???
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Umesh

There is a performance tuning document on docs.sun.com at:
http://docs.sun.com/app/docs/doc/819-0084
Is there a specific question you're looking for an answer to?
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Bit char string...need help

Hi I am trying to convert a bit char string to something useful. Basically I have an activex tool that allows me acess to a serial port based scale.
I send a weight request command and it sends me this gibberish:
°®°° ìb ÇR
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\u00b0\u00ae\u00b0\u00b0, on line 1, column 21, is not a valid identifer name.
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Sun ONE 6.1 Performance Issues - Sleeping / Hanging

We have been running the Sun family of web servers for many years now, and ran Netscape Enterprise Server 3.6 for a long time.
Several months ago we upgraded to Sun ONE Web Server 6.0 and then 6.1. We have not had any issues until the past few weeks.
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Active Sessions 105
Total Sessions Created 158/256
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default-bucket (Default bucket)
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Why do I have all of these processes queued on the server?
Is DNS causing this? I know Sun ONE 6.x does NOT have asynchronous DNS implemented (although it is an option, it has no effect). Did Netscape Enterprise Server 3.6 has ASync DNS implemented?
We would like to avoid turning off DNS resolution for a number of reasons. However, what really bothers us is that this web server's performance suddenly became a problem while the other 5 servers see FANTASTIC performance and never go to sleep (although some of them are NOT accessible from the general Internet).
Has anyone else seen this?
As a side note, all of these web servers are using a NSAPI plugin that I wrote years ago. It's purpose is access control and automatic forwarding to different pages. It also uses DNS hostnames, but thinking it might be a problem with this web server, I've disabled DNS on the plug-in. It has not helped. Again, this plug-in has worked great for years and is quite straightforward and simple.
Something tells me there is more going on here - thoughts or ideas?
We're getting immensely frustrated here.
In desperation we've made some magnus.conf changes but to no real effect (partially listed below):
DNS on
RqThrottle 256
StackSize 131072
CGIWaitPid on
AsyncDNS off
KeepAliveThreads 2
MaxKeepAliveConnections 256
UseNativePoll 1
RcvBufSize 8192
# default=100
KeepAliveQueryMeanTime 25
# default=100
KeepAliveQueryMaxSleepTime 25
# CGI
MinCgiStubs 10
MaxCgiStubs 50
CGIStubIdleTimeout 45
CGIExpirationTimeout 90
Thanks for any pointers,
--Dave

Note that at the moment it seems to be responding normally, but we still have a lot of threads hanging around - very strange...
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One Char String - performance

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