Reading Zipfile into Memory

Can someone please show me how I can get the 5th field (comma seperated) out of a zipped file? I am having NO luck. I need to get it into a variable.

Crosspost!

Similar Messages

Reading Lots of Objects into Memory

I need to read thousands of fairly large objects from an object database to the point that the JMV memory runs out.
A solution is to: read, use and discard as opposed to loading all the objects into memory at once -pretty simple but I want to do it right. I have a general idea on how to implement the approach but I need your help in locating some reading materials, code snipplets and/or best practices.
Thanks!

If you're using thousands of objects you might look into the Flyweight Pattern (depending on what these objects are and what state they have). You might also look into increasing the amount of memory available to the JVM via that -Xms switch.
Aside from that, if you reuse the same reference name (variable name)(s) you'll allow the Garbage Collector to recover that memory.
Good Luck
Lee

Reading entire txt file into memory?

When you are using BufferedReader to read info into a buffer, that means you are reading the file into memory, correct? (Is that what buffer means?)
I want to look for pattern matches in text files (about 1000 of them) using the regex utils. But I don't want to read and examine the text files line by line. I want to read in the entire text file into memory first and then look for the pattern matches. The text files generally don't exceed about 15K in size. I'm only going one file at a time, too, so this won't give me any out of memory errors, will it?
And more importantly, how do I do it? I mean the "reading in the file" part only. I have my RegEx, I have my array of files to examine already. I just can't figure out the right code to use to read each file into memory before I look for pattern matches.
Could someone help, please?

When you are using BufferedReader to read info into a
buffer, that means you are reading the file into
memory, correct? (Is that what buffer means?)Yes.
I want to look for pattern matches in text files
(about 1000 of them) using the regex utils. But I
don't want to read and examine the text files line by
line.Why not?
I want to read in the entire text file into
memory first and then look for the pattern matches.Why?
The text files generally don't exceed about 15K in
size. I'm only going one file at a time, too, so
this won't give me any out of memory errors, will
it?Depends on how much memory you've given the VM and how much of that it's using already at the time you read the files, but in general, probably not a problem.
And more importantly, how do I do it? I mean the
"reading in the file" part only.Use BufferedReader to read line by line and then append each line (plus a newline, since BR.readLine() strips those off) to a StringBuilder.
Or use a BufferedInputStream and and array that's as big as the file, and in a loop, try to read as much as is left into that array at an offset equal to how much has been read so far.
I still think this is probably not a good approach though.

Reading a text data file into memory

hi,
I have a text file which contains data, The text file is parsed and objects are created. The problem is the text file is quite huge measuring upto 1.8~2 Mb. The format of the text file is as follows
Units: METRIC (atm, m3)
* Step: 1 Time: 0.00
* Average Field Pressure : 204.14
* Region 1 Pressure : 204.14
Well GROUP Layer Blk_Pressure BHP ResRate OilRate WaterRate GasRate KhProd Windex PindeWELLTYPE
1 FIELD 1 204.14 49.33 6601.22 6568.10 37.14 538.07 99999.00 260.35 99999.00 P
1 FIELD 2 204.14 50.34 6558.13 6525.23 36.90 534.56 99999.00 260.35 99999.00 P
1 FIELD 3 204.14 51.35 6515.04 6482.36 36.65 531.04 99999.00 260.35 99999.00 P
1 FIELD Tot 204.14 50.34 19674.40 19575.69 110.69 1603.67 99999.00 99999.00 99999.00 P
2 FIELD 1 204.14 377.66 7573.96 0.00 7403.68 0.00 99999.00 260.35 99999.00 I
2 FIELD 2 204.14 378.40 7606.33 0.00 7435.32 0.00 99999.00 260.35 99999.00 I
2 FIELD 3 204.14 379.14 7638.70 0.00 7466.96 0.00 99999.00 260.35 99999.00 I
2 FIELD Tot 204.14 378.40 22818.99 0.00 22305.95 0.00 99999.00 99999.00 99999.00 I
* Step: 2 Time: 20.23
* Average Field Pressure : 300.11
* Region 1 Pressure : 300.11
Well GROUP Layer Blk_Pressure BHP ResRate OilRate WaterRate GasRate KhProd Windex PindeWELLTYPE
1 FIELD 1 194.20 49.33 858.83 853.40 5.36 68.22 99999.00 260.35 99999.00 P
1 FIELD 2 194.48 50.34 871.71 866.22 5.42 69.35 99999.00 260.35 99999.00 P
1 FIELD 3 194.76 51.35 884.86 879.29 5.48 70.49 99999.00 260.35 99999.00 P
1 FIELD Tot 194.48 50.34 2615.40 2598.91 16.26 208.06 99999.00 99999.00 99999.00 P
2 FIELD 1 370.40 377.66 912.25 0.00 891.74 0.00 99999.00 260.35 99999.00 I
2 FIELD 2 371.26 378.40 895.75 0.00 875.61 0.00 99999.00 260.35 99999.00 I
2 FIELD 3 372.12 379.14 879.29 0.00 859.52 0.00 99999.00 260.35 99999.00 I
2 FIELD Tot 371.26 378.40 2687.28 0.00 2626.86 0.00 99999.00 99999.00 99999.00 I
The Step goes on till like 3000, I am creating an object for each step which inturn has nested object for each well and the well in turn for each layer. In the above case of step 3 the object would be
class Step 2{
inner class well
{ //for well 1
inner class layer { // for layer 1 }
inner class layer {/ for layer 2 }
inner class layer {/ for layer 3 }
inner class well
{ //for well 2
inner class layer { // for layer 1 }
inner class layer {/ for layer 2 }
inner class layer {/ for layer 3 }
This architecture of mine is proving to be heavy as I would end up with around 9000 Java objects in memory, though my classes only have have int, float, String data items. I am using this data to plot graphs, so I guess it wouldnt be optimal to read data from text file for each plot.
So in short the problem is can anyone tell a better way to read the data into memory ? given that there could be 3000 steps in the format given above.
Thanks
AM

I have implemented and it takes around 30-45 sec to parse and also the GUI has become very slow. I query the objects for multiple combinations of graphs.
The data from the objects is being used to feed the graphs on my GUI. I have a number of options on my GUI for different kinds of graphs, for each combination chosen the Objects are queried for the data. The GUI is written using Swing.
So is there anyway I can fine tune the application, any tips about the object architecture or how to improve the speed. I am also explicitly running the garbage collector a few times in my program. Also how can I make JVM occupy lesser memory so that my program can have more memory.
Thanks
am

Read a file without loading it into memory

I have a VERY large file filled with words. I want to determine if a String in my program matches one of them. Loading the entire file into memory would take a long time and would use way too much memory. Is there some way to load just the part I need each time or make the comparison directly from the file on the hard disk?

The file is static, so your plan seems to have merit.
I've only used sequential files before, but I'm
assuming this would require a random access file since
you have to begin reading at a specified offset. Am I
correct?Yes.
In addition, if this file is fixed-length "records" so that you could programmatically determine the word offsets without having to keep a map of indexes in memory, you could just employ a search algorithm (I forget what this one is called) - you could start by defining 2 endpoints, initially at offset 0 and the offset of the last word.
Iteratively read the word halfway between the 2 endpoints, adjusting the endpoints until a match is found or the endpoints converge.

IB Error: Unable to read symbols from "UIKit" (not yet mapped into memory)

I created a simple view program for iPhone, using IB to add a button and a label, once the button is clicked, the label text is changed.
I am able to compile it fine, and ran it. The program/view showed up. But when I clicked on the button, the console showed this message:
This GDB was configured as "i386-apple-darwin".warning: Unable to read symbols for "/System/Library/Frameworks/UIKit.framework/UIKit" (file not found).
warning: Unable to read symbols from "UIKit" (not yet mapped into memory).
I checked UIKit info, it's physically (full path) at:
/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS2.0.sdk/System/Lib rary/Frameworks/UIKit.framework
The relative path to SKD is:
System/Library/Frameworks/UIKit.framework
I'm running the latest SDK beta 8, OS X 10.5.4 latest update.
Anyone had this bizarre problem? I was able to run all Apple samples fine.
Please help!
THanks!

The answer is mentioned in a few other posts, but I thought I'd repeat it here, so that it's easier to find this solution in the future.
I got the same problem trying to build an iPhone-Simulator application using another build process -- in this case, Boost Build. When I tried to run the program, it gave me the same nonsensical dynamic-library error.
The problem is that the application you built for the iPhone Simulator is NOT a real application, even though it looks like one. You need to run it from within Xcode.
In my case, I got around the problem by building the GLPaint sample using Xcode, copying over the executable it generated with the one I generated via Boost Build, then running GLPaint (actually my program now) from within Xcode. Then it worked.
So far, it seems that Macintosh and iPhone are very unfriendly platforms to someone that's trying to port an existing project. Any attempt to do something, without completely buying into the Apple way of doing everything, leads to a torrent of cryptic undocumented errors. Even an old Unix guru like me can't keep up.

Read a folder and contents into memory

Hello All,
I want to put an entire folder (and it's contents) into memory.
Use Case :
1) Computer 1 has a folder called "foo" with 5 files in it. I want to run some program here which will serialize down into some file call it "fooserialized"
2) Computer 2 deserializes "fooserialized" and can then create folder "foo" with all of it's original contents.
Any suggestions? I browsed through the java.util.zip package with no avail.
Thanks!
TheCypher

I want to do this simply as possible.tar cfj archive.tar.bz2 <files>
<send to other computer>
tar xfj archive.tar.bz2

Load an existing Berkeley DB file into memory

Dear Experts,
I have created some Berkeley DB (BDB) files onto disk.
I noticed that when I issue key-value retrievals, the page faults are substantial, and the CPU utilization is low.
One sample of the time command line output is as follow:
1.36user 1.45system 0:10.83elapsed 26%CPU (0avgtext+0avgdata 723504maxresident)k
108224inputs+528outputs (581major+76329minor)pagefaults 0swaps
I suspect that the bottleneck is the high frequency of file I/O.
This may be because of page faults of the BDB file, and the pages are loaded in/out of disk fairly frequently.
I wish to explore how to reduce this page fault, and hence expedite the retrieval time.
One way I have read is to load the entire BDB file into main memory.
There are some example programs on docs.oracle.com, under the heading "Writing In-Memory Berkeley DB Applications".
However, I could not get them to work.
I enclosed below my code:
--------------- start of code snippets ---------------
/* Initialize our handles */
DB *dbp = NULL;
DB_ENV *envp = NULL;
DB_MPOOLFILE *mpf = NULL;
const char *db_name = "db.id_url"; // A BDB file on disk, size 66,813,952
u_int32_t open_flags;
/* Create the environment */
db_env_create(&envp, 0);
open_flags =
DB_CREATE | /* Create the environment if it does not exist */
DB_INIT_LOCK | /* Initialize the locking subsystem */
DB_INIT_LOG | /* Initialize the logging subsystem */
DB_INIT_MPOOL | /* Initialize the memory pool (in-memory cache) */
DB_INIT_TXN |
DB_PRIVATE; /* Region files are not backed by the filesystem.
* Instead, they are backed by heap memory. */
* Specify the size of the in-memory cache.
envp->set_cachesize(envp, 0, 70 * 1024 * 1024, 1); // 70 Mbytes, more than the BDB file size of 66,813,952
* Now actually open the environment. Notice that the environment home
* directory is NULL. This is required for an in-memory only application.
envp->open(envp, NULL, open_flags, 0);
/* Open the MPOOL file in the environment. */
envp->memp_fcreate(envp, &mpf, 0);
int pagesize = 4096;
if ((ret = mpf->open(mpf, "db.id_url", 0, 0, pagesize)) != 0) {
envp->err(envp, ret, "DB_MPOOLFILE->open: ");
goto err;
int cnt, hits = 66813952/pagesize;
void *p=0;
for (cnt = 0; cnt < hits; ++cnt) {
db_pgno_t pageno = cnt;
mpf->get(mpf, &pageno, NULL, 0, &p);
fprintf(stderr,"\n\nretrieve %5d pages\n",cnt);
/* Initialize the DB handle */
db_create(&dbp, envp, 0);
* Set the database open flags. Autocommit is used because we are
* transactional.
open_flags = DB_CREATE | DB_AUTO_COMMIT;
dbp->open(dbp, // Pointer to the database
NULL, // Txn pointer
NULL, // File name -- NULL for inmemory
db_name, // Logical db name
DB_BTREE, // Database type (using btree)
open_flags, // Open flags
0); // File mode. defaults is 0
DBT key,data; int test_key=103456;
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
key.data = (int*)&test_key;
key.size = sizeof(test_key);
dbp->get(dbp, NULL, &key, &data, 0);
printf("%d --> %s ", *((int*)key.data),(char*)data.data );
/* Close our database handle, if it was opened. */
if (dbp != NULL) {
dbp->close(dbp, 0);
if (mpf != NULL) (void)mpf->close(mpf, 0);
/* Close our environment, if it was opened. */
if (envp != NULL) {
envp->close(envp, 0);
/* Final status message and return. */
printf("I'm all done.\n");
--------------- end of code snippets ---------------
After compilation, the code output is:
retrieve 16312 pages
103456 --> (null) I'm all done.
However, the test_key input did not get the correct value retrieval.
I have been reading and trying this for the past 3 days.
I will appreciate any help/tips.
Thank you for your kind attention.
WAN
Singapore

Hi Mike
Thank you for your 3 steps:
-- create the database
-- load the database
-- run you retrievals
Recall that my original intention is to load in an existing BDB file (70Mbytes) completely into memory.
So following your 3 steps above, this is what I did:
Step-1 (create the database)
I have followed the oracle article on http://docs.oracle.com/cd/E17076_02/html/articles/inmemory/C/index.html
In this step, I have created the environment, set the cachesize to be bigger than the BDB file.
However, I have some problem with the code that opens the DB handle.
The code on the oracle page is as follow:
* Open the database. Note that the file name is NULL.
* This forces the database to be stored in the cache only.
* Also note that the database has a name, even though its
* file name is NULL.
ret = dbp->open(dbp, /* Pointer to the database */
NULL, /* Txn pointer */
NULL, /* File name is not specified on purpose */
db_name, /* Logical db name. */
DB_BTREE, /* Database type (using btree) */
db_flags, /* Open flags */
0); /* File mode. Using defaults */
Note that the open(..) API does not include the BDB file name.
The documentation says that this is so that the API will know that it needs an in-memory database.
However, how do I tell the API the source of the existing BDB file from which I wish to load entirely into memory ?
Do I need to create another DB handle (non-in-memory, with a file name as argument) that reads from this BDB file, and then call DB->put(.) that inserts the records into the in-memory DB ?
Step-2 (load the database)
My question in this step-2 is the same as my last question in step-1, on how do I tell the API to load in my existing BDB file into memory?
That is, should I create another DB handle (non-in-memory) that reads from the existing BDB file, use a cursor to read in EVERY key-value pair, and then insert into the in-memory DB?
Am I correct to say that by using the cursor to read in EVERY key-value pair, I am effectively warming the file cache, so that the BDB retrieval performance can be maximized ?
Step-3 (run your retrievals)
Are the retrieval API, e.g. c_get(..), get(..), for the in-memory DB, the same as the file-based DB ?
Thank you and always appreciative for your tips.
WAN
Singapore

How to load a BDB file into memory?

The entire BDB database needs to reside in memory for performance reasons, it needs to be in memory all the time, not paged in on demand. The physical memory and virtual process address space are large enough to hold this file. How can I load it into memory just before accessing the first entry? I've read the C++ API reference, and it seems that I can do the following:
1, Create a DB environment;
2, Call DB_ENV->set_cachesize() to set a memory pool large enough to hold the BDB file;
3, Call DB_MPOOLFILE->open() to open the BDB file in memory pool of that DB environment;
4, Create a DB handle in that DB environment and open the BDB file (again) via this DB handle.
My questions are:
1, Is there a more elegant way instead of using that DB environment? If the DB environment is a must, then:
2, Does step 3 above load the BDB file into memory pool or just reserve enough space for that file?
Thanks in advance,
Feng

Hello,
Does the documentation on "Memory-only or Flash configurations" at:
http://download.oracle.com/docs/cd/E17076_02/html/programmer_reference/program_ram.html
answer the question?
From there we have:
By default, databases are periodically flushed from the Berkeley DB memory cache to backing physical files in the filesystem. To keep databases from being written to backing physical files, pass the DB_MPOOL_NOFILE flag to the DB_MPOOLFILE->set_flags() method. This flag implies the application's databases must fit entirely in the Berkeley DB cache, of course. To avoid a database file growing to consume the entire cache, applications can limit the size of individual databases in the cache by calling the DB_MPOOLFILE->set_maxsize() method.
Thanks,
Sandra

Installing Flash CS5.5 corrupted my CS5 Fla - Could not load scene into memory. Your document may be

I have a FLA that worked fine in CS5, I have copies of the file going back 6 months. Every file I open gives me this error: Could not load scene into memory. Your document may be damaged.
How could every fla I've backed up give the same error? They all worked fine in CS5. Does anyone know of a fix? Or do I have to go back to CS5?
Thanks!

I reinstalled Flash Pro CS5 and it opens up all my FLA's (of the same project) perfectly. But Flash Pro CS5.5 gives me this error: Could not load scene into memory. Your document may be damaged.
So is CS5.5 unusable?
cheeres.

Missing/empty symbols, "Could not load scene into memory. Your document may be damaged." CS6

Hey folks,
we've been getting this problem a lot. We had it in Flash CS5.5 and still have it CS6.
We're animating a series in Flash and this problem keeps cropping up way to often, but seems totally random.
Basically I'll be working on a .fla saving regular versions through out the day, no problems. I'll close the file down. Then I (or someone else on a different computer) will open it up and I'll get the error msg "Could not load scene into memory. Your document may be damaged." Everything will be fine except for a few missing graphic symbols. Sometimes just the one, sometimes a whole bunch. So where the symbol should be on the stage, instead you get a small white square, but it still contains the animation information. So it will still move about the stage. If I bring in the same symbol from an old scene I can swap them out and the problem is fixed, (until it does it again on a totally different graphic symbol).
If i select the symbol in the library the preview is white/blank and i can't go into it to edit. When I select the symbol on the stage, the "instance of:" gives me a blank "_ _ _" in the properties tab. How ever if i right click show in library it does show me the correct (although broken as in blank) symbol in the library.
I havent been able to reproduce this problem on purpose but I'd say it happens in roughly one scene out of 10. Its seems to happen at random, I know there must be something in common but i havent figured out what. Its going on in heavy scenes (large library multipule characters), lite scenes (just the one character). Its not like it happens to the same symbol, different ones each time. Everything is local to the scene, all elements are created in flash. We are working across a network but as everything is local to the scene i don't see how that would be a problem. Also we don't have duplicate named symbols. It also won't necessarily affect something that has been changed since the last version. could be a background element thats been there, untouched since the first version of the scene.
One point on how we set up our scenes which may be relevant. Start with empty scene, copy and paste symbols from other scenes to populate. Save.
The problem could appear on say version 4 or version 36. Older versions are usually fine.
So to sum up. Flash file is fine when we save it, open it up again later and a symbol will have disappeared. It's happening far too often.
I know how to fix the problem, thats not what I'm asking. I need to know WHY its doing it so we can stop this from happening in the first place.
Phew! Thanks for reading this far. Any help would be highly appreciated.
Sander/

Can you elaborate on how you use the network? Are you working from FLA/XFLs stored on a machine across a network (and saving them across the network)? I had plenty of those issues and Adobe has always warned not to work across a network. I just fell into the habit of copying over what I need to work on locally, then updating the file servers at the end of the day. Nothing was corrupt after that.
Also lately in CS5.5 (not CS6 yet) I had noticed that I could change some graphics assets, close the document in OS X and open in Windows only to find freshly updated graphics reverted back. What's even more odd is if the OS X machine that made the changes opens it the changes are still made. This happens vice versa as well. My only solution on that was not to work cross-platform with other machines on a network unless absolutely necessary.

Loading a large number of strings into memory quickly

Hello,
I'm working on an iPhone application where I need to load a large number of strings into memory. Currently I'm simply reading from a file where each string is stored in plain text on a single line. I read the file contents into a string using stringWithContentsOfFile and then I create an NSSet object using NSSet setWithArray:[string componentsSeparatedByString:@"\n"]];
This works like a charm but takes around 8 seconds to load on the iPhone. I'm looking for ways to speed this up. I've already tried a few things which weren't any faster:
1) I used [NSKeyedArchiver archiveRootObject:myList toFile:appFile]; to store the NSSet data structure. Then instead of reading the text file storage. I read this file using [NSKeyedUnarchiver unarchiveObjectWithFile:appFile]; This was actually very slow and created a strings file that was about 2x the size of the original plain text.
2) Instead of using an NSSet, I used and NSDictionary and used writeToFile and dictionaryWithContentsOfFile. This was also no faster.
3) Finally I tried using the NSDictionary to write to a binary file format using NSPropertyListSerialization. This was also not any faster.
I've been thinking about using SQLite instead of the flat file read, but I haven't had a chance to prototype that out to see if it would be faster. It's important that I can do fast searches for specific strings, which is why I originally used a set.
Does any one else have any ideas how to load this into memory faster? If all else fails, I'm simply going to load the strings into memory using a separate thread on application launch so I don't prevent the user from getting to the main menu for 8 seconds.
Thanks,
-Keith

I'd need to know more about what you're doing, but from what you're describing I think you should try to change your algorithm.
For example: Instead of distributing one flat file, split your list of strings into 256 files, based on the first two hex digits of their MD5 hashes*. (Two digits might not be enough--you might need three or four. You may also want to use folders, especially if you need more than two digits.) When testing if a string exists, first calculate its MD5 hash and extract the necessary number of digits, then load that file into memory and scan its list. (You can cache these lists in memory so that you only have to load each file once--just make sure that a didReceiveMemoryWarning message will empty those caches.)
Properly configured, SQLite may be faster than the eight second load time you talk about, especially if you ensure it indexes the column you store the strings in. But it's probably overkill for this application.
\* A hash is a numeric code calculated from a string; on average, changing a single bit anywhere in the string should change half the bits in the hash, so even very similar strings should generate very different hashes. I suggest using MD5 instead of -\[NSString hash\] because the hash method is not guaranteed to return the same results on Mac OS and iPhone OS, or on different releases of either OS. You could also use a different algorithm, like a CRC; these are faster but I'm not as familiar with them. This thread discusses calculating MD5 hashes on iPhone OS: http://discussions.apple.com/thread.jspa?messageID=7362074
Message was edited by: Brent Royal-Gordon

Urgent help on reading data into ByteBuffer

Hi,
I am trying to read data into ByteBuffer using SocketChannel.
The following code working fine but the problem is with ByteBuffer size.
The data varies from request to request .
How do I read data into ByteBuffer with out specifing size .
The problem with size is some records has more than 500 bytes and some are less than 500 bytes.
I want to read all the data .. ( even if it has more than 500 bytes ..)
How do i solve this problem ..
Is there any way to read data dynamically from socket channel ...
Any help on this please ...
The data I have to read is in the following format ..
XXX ... yyyyy
AAA
BBBBBBBBBBBBBBBBBBBBBB
CCCCCCCCCCCCCCCCCCCC
DDDDDDDDDDDDDDDDDDDDDDd
etc ...
Here is my Code:
public ByteBuffer getResponse(byte[] request) throws Exception {
int lenth = 500;
InetSocketAddress isa = new InetSocketAddress("ip", port);
SocketChannel channel = SocketChannel.open(isa);
ByteBuffer requestBuffer = ByteBuffer.wrap(request);
channel.write(requestBuffer);
ByteBuffer responseByteBuffer = ByteBuffer.allocate(length);
int num = 0;
while (num == 0 ) {
responseByteBuffer.rewind();
num = channel.read(responseByteBuffer);
channel.close();
return responseByteBuffer;
Thanks.

Two possible solutions
1. Read in as many bytes as you can until you hit the EOS OR you fill the byte buffer. If you fill the buffer (try checking for BufferUnderFlowException), you could move the read bytes into a dynamically allocated memory Collection such as an ArrayList. When you hit the EOF, you could then do whatever else you need to do from then on.
2. I use this option: Implement a site local protocol for transmitting data. Provide a header first containing 2 ints (compressed size, uncompressed size - so you can also use compression when sending), and send the remainder as a payload.
Therefore
Read in the header first (always 8 bytes)
Then extract those integer values. They will tell you how much is being sent. Set you byte buffer for the payload to be the correct size for this transmission.
Reset and wait for next connection

Loading images into memory

I have an applet that I need to load images into memory. For instance, lets say I am in the first section of the applet. While that section is being showed, I want to load the background image of the second section into memory.
To load the initial image into momory, I am just using a Mediatracker. No problem there. But I don't want to load all 20 backgrounds into memory at the same time as they take a lot of time. My understanding is that if I create a new MediaTracker while the first chapter is running, it will potentially cause some chaos, as that will stop my thread from running while I have an image loading.
Somebody told me perhaps I could create a new thread and have that thread load the backgroudn into momory? Perhaps something like this?
public class TestClass extends JApplet {
     private TestClass thisClass;
     public void init() {
          thisClass = this;
          Runnable r = new Runnable() {
               public void run() {
                    MediaTracker tracker = new MediaTracker(thisClass);
                    Image nextImage = getImage( getDocumentBase(), getImagePath() +"img1.jpg");
                    tracker.addImage(nextImage,0);
                    try {
                         tracker.waitForID(0);
                    } catch (InterruptedException ie) {
                         System.out.println(ie.toString());
          Thread t = new Thread(r);
          t.setDaemon(false);
          t.start();
          while(t.isAlive()) {
               int i = 1;
          t.stop();
          t.destroy();
}No idea if I am on the right track or not? Another friend told me something about swing helpers but couldn't tell me much more?
Thanks in advance!

I use media tracker when I need information about how percent the image is loaded. you can use JLabel to load the images since it has own image observer in it.
hope you just want to deal with it. easiest way I can offer :)

How can I load pattern matching images into memory?

I discovered this problem by accident when our network went down. I could not run my VI because the .png file used for pattern matching was on a network drive. My concern it the amount of time that is required to read a network file. Is there a way to load the file into memory when the VI is opened?

Brian,
Thank you for contacting National Instruments. For most pattern matching programs, the pattern file should only be read from file once and is then copy to a buffer on the local machine. If you examine your code, or an example program for pattern matching, you should see at least two IMAQ Create VI called somewhere near the front of your code. This VI basically creates a memory location and most likely will be called once for your pattern image and once for the image you are searching.
Unless you are specifically calling a File Dialog VI where you are given a dialog box to open a file or have hard coded the file path so that it is read each iteration of your code, then your pattern file should only need to be called at the beginning of your application, th
us causing only one file read over the network for that image. Therefore your program most likely already loads the image in memory once it is read and should not be accessing the network constantly.
Again, I would recommend taking a look at your code to make sure you are not causing a file access every time and then you should be ready to go. Just in case you do have the network go down, I would recommend keeping a copy of the image locally and, if you are feeling ambitious, you can programmatically have your program read the file locally if the network file returns an error.
Good luck with your application and let us know if we can be of any further assistance.
Regards,
Michael
Applications Engineer
National Instruments

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