Is there any way in Java (1.6+) to retrieve the partition disk structure? (For example: NTFS, FAT32, HFS+, or EXT3.)
External libraries are permitted.
Thanks,
Gianni
Under OS X the output of "mount" includes the file system:
ravn:~ ravn$ mount
/dev/disk0s2 on / (hfs, local, journaled)
devfs on /dev (devfs, local, nobrowse)
map -hosts on /net (autofs, nosuid, automounted, nobrowse)
map auto_home on /home (autofs, automounted, nobrowse)
Here / is of type hfs
If this doesn't help then - no. You'll need a native library and some OS dependent code for it.
You could use Runtime.getRuntime().exec() to execute a command like sfdisk and then parse the output.
sfdisk -l /dev/hdc
Unfortunately, it isn't very platform independent.
Related
I have a long list of JVM parameter values:
-XX:+UseSerialGC -XX:+ResizePLAB -XX:-ResizeOldPLAB -XX:-AlwaysPreTouch -XX:-ParallelRefProcEnabled -XX:+ParallelRefProcBalancingEnabled -XX:+UseTLAB -XX:-ResizeTLAB -XX:-ZeroTLAB -XX:-FastTLABRefill -XX:+NeverActAsServerClassMachine -XX:-AlwaysActAsServerClassMachine -XX:+UseAutoGCSelectPolicy -XX:+UseAdaptiveSizePolicy -XX:+UsePSAdaptiveSurvivorSizePolicy -XX:-UseAdaptiveGenerationSizePolicyAtMinorCollection -XX:+UseAdaptiveGenerationSizePolicyAtMajorCollection -XX:+UseAdaptiveSizePolicyWithSystemGC -XX:+UseAdaptiveGCBoundary -XX:+UseAdaptiveSizePolicyFootprintGoal -XX:-UseAdaptiveSizeDecayMajorGCCost -XX:+UseGCOverheadLimit -XX:+DisableExplicitGC -XX:-CollectGen0First -XX:+BindGCTaskThreadsToCPUs -XX:+UseGCTaskAffinity -XX:YoungPLABSize=3397 -XX:OldPLABSize=1123 -XX:GCTaskTimeStampEntries=240 -XX:TargetPLABWastePct=6 -XX:PLABWeight=75 -XX:OldPLABWeight=46 -XX:MarkStackSize=4617021 -XX:MarkStackSizeMax=713160576 -XX:RefDiscoveryPolicy=0 -XX:InitiatingHeapOccupancyPercent=48 -XX:MaxRAM=139765086242 -XX:ErgoHeapSizeLimit=0 -XX:MaxRAMFraction=4 -XX:DefaultMaxRAMFraction=4 -XX:MinRAMFraction=2 -XX:InitialRAMFraction=61 -XX:AutoGCSelectPauseMillis=5557 -XX:AdaptiveSizeThroughPutPolicy=0 -XX:AdaptiveSizePausePolicy=0 -XX:AdaptiveSizePolicyInitializingSteps=28 -XX:AdaptiveSizePolicyOutputInterval=0 -XX:AdaptiveSizePolicyWeight=12 -XX:AdaptiveTimeWeight=19 -XX:PausePadding=0 -XX:PromotedPadding=3 -XX:SurvivorPadding=3 -XX:ThresholdTolerance=10 -XX:AdaptiveSizePolicyCollectionCostMargin=49 -XX:YoungGenerationSizeIncrement=16 -XX:YoungGenerationSizeSupplement=104 -XX:YoungGenerationSizeSupplementDecay=9 -XX:TenuredGenerationSizeIncrement=22 -XX:TenuredGenerationSizeSupplement=117 -XX:TenuredGenerationSizeSupplementDecay=2 -XX:MaxGCPauseMillis=13557897735059052544 -XX:GCPauseIntervalMillis=0 -XX:MaxGCMinorPauseMillis=16119267456708329472 -XX:GCTimeRatio=73 -XX:AdaptiveSizeDecrementScaleFactor=4 -XX:AdaptiveSizeMajorGCDecayTimeScale=11 -XX:MinSurvivorRatio=1 -XX:InitialSurvivorRatio=6 -XX:BaseFootPrintEstimate=272901592 -XX:GCHeapFreeLimit=2 -XX:PrefetchCopyIntervalInBytes=654 -XX:PrefetchScanIntervalInBytes=748 -XX:PrefetchFieldsAhead=1 -XX:ProcessDistributionStride=3
that I need to change before running a program. The values for these parameters will be dynamically determined, thus I need to be able to change these values repeatedly. The program is executed inside a docker container and is a REST endpoint developed using springboot.
Is there some kind of configuration file where I can dynamically set these parameters or how can this be done?
Is there some kind of configuration file where I can dynamically set these parameters
No.
or how can this be done?
You just write some code to do it. Possibly a shell script or a Windows batch file. Possibly in in some other scripting language. Possibly even in Java.
For example, this uses a helper Java program to do the "dynamic" stuff and generate some JVM options. These are then supplied when launching the JVM for the real application.
#!/bin/sh
OPTS=`java com.acme.GenerateJVMOptions some parameters`
java $OPTS com.acme.TheRealApplication some more parameters
I have a long list of JVM parameter values:
-XX:+UseSerialGC -XX:+ResizePLAB -XX:-ResizeOldPLAB -XX:-AlwaysPreTouch -XX:-ParallelRefProcEnabled -XX:+ParallelRefProcBalancingEnabled -XX:+UseTLAB -XX:-ResizeTLAB -XX:-ZeroTLAB -XX:-FastTLABRefill -XX:+NeverActAsServerClassMachine -XX:-AlwaysActAsServerClassMachine -XX:+UseAutoGCSelectPolicy -XX:+UseAdaptiveSizePolicy -XX:+UsePSAdaptiveSurvivorSizePolicy -XX:-UseAdaptiveGenerationSizePolicyAtMinorCollection -XX:+UseAdaptiveGenerationSizePolicyAtMajorCollection -XX:+UseAdaptiveSizePolicyWithSystemGC -XX:+UseAdaptiveGCBoundary -XX:+UseAdaptiveSizePolicyFootprintGoal -XX:-UseAdaptiveSizeDecayMajorGCCost -XX:+UseGCOverheadLimit -XX:+DisableExplicitGC -XX:-CollectGen0First -XX:+BindGCTaskThreadsToCPUs -XX:+UseGCTaskAffinity -XX:YoungPLABSize=3397 -XX:OldPLABSize=1123 -XX:GCTaskTimeStampEntries=240 -XX:TargetPLABWastePct=6 -XX:PLABWeight=75 -XX:OldPLABWeight=46 -XX:MarkStackSize=4617021 -XX:MarkStackSizeMax=713160576 -XX:RefDiscoveryPolicy=0 -XX:InitiatingHeapOccupancyPercent=48 -XX:MaxRAM=139765086242 -XX:ErgoHeapSizeLimit=0 -XX:MaxRAMFraction=4 -XX:DefaultMaxRAMFraction=4 -XX:MinRAMFraction=2 -XX:InitialRAMFraction=61 -XX:AutoGCSelectPauseMillis=5557 -XX:AdaptiveSizeThroughPutPolicy=0 -XX:AdaptiveSizePausePolicy=0 -XX:AdaptiveSizePolicyInitializingSteps=28 -XX:AdaptiveSizePolicyOutputInterval=0 -XX:AdaptiveSizePolicyWeight=12 -XX:AdaptiveTimeWeight=19 -XX:PausePadding=0 -XX:PromotedPadding=3 -XX:SurvivorPadding=3 -XX:ThresholdTolerance=10 -XX:AdaptiveSizePolicyCollectionCostMargin=49 -XX:YoungGenerationSizeIncrement=16 -XX:YoungGenerationSizeSupplement=104 -XX:YoungGenerationSizeSupplementDecay=9 -XX:TenuredGenerationSizeIncrement=22 -XX:TenuredGenerationSizeSupplement=117 -XX:TenuredGenerationSizeSupplementDecay=2 -XX:MaxGCPauseMillis=13557897735059052544 -XX:GCPauseIntervalMillis=0 -XX:MaxGCMinorPauseMillis=16119267456708329472 -XX:GCTimeRatio=73 -XX:AdaptiveSizeDecrementScaleFactor=4 -XX:AdaptiveSizeMajorGCDecayTimeScale=11 -XX:MinSurvivorRatio=1 -XX:InitialSurvivorRatio=6 -XX:BaseFootPrintEstimate=272901592 -XX:GCHeapFreeLimit=2 -XX:PrefetchCopyIntervalInBytes=654 -XX:PrefetchScanIntervalInBytes=748 -XX:PrefetchFieldsAhead=1 -XX:ProcessDistributionStride=3
that I need to change before running a program. The values for these parameters will be dynamically determined, thus I need to be able to change these values repeatedly. The program is executed inside a docker container and is a REST endpoint developed using springboot.
Is there some kind of configuration file where I can dynamically set these parameters or how can this be done?
Is there some kind of configuration file where I can dynamically set these parameters
No.
or how can this be done?
You just write some code to do it. Possibly a shell script or a Windows batch file. Possibly in in some other scripting language. Possibly even in Java.
For example, this uses a helper Java program to do the "dynamic" stuff and generate some JVM options. These are then supplied when launching the JVM for the real application.
#!/bin/sh
OPTS=`java com.acme.GenerateJVMOptions some parameters`
java $OPTS com.acme.TheRealApplication some more parameters
I want to parallelize my data writing process. I am writing a data frame to Oracle Database. This data has 4 million rows and 8 columns. It takes 6.5 hours without parallelizing.
When I try to go parallel, I get the error
Error in checkForRemoteErrors(val) :
7 nodes produced errors; first error: No running JVM detected. Maybe .jinit() would help.
I know this error. I can solve it when I work with single cluster. But I do not know how to tell other clusters the location of Java. Here is my code
Sys.setenv(JAVA_HOME='C:/Program Files/Java/jre1.8.0_181')
library(rJava)
library(RJDBC)
library(DBI)
library(compiler)
library(dplyr)
library(data.table)
jdbcDriver =JDBC("oracle.jdbc.OracleDriver",classPath="C:/Program Files/directory/ojdbc6.jar", identifier.quote = "\"")
jdbcConnection =dbConnect(jdbcDriver, "jdbc:oracle:thin:#//XXXXX", "YYYYY", "ZZZZZ")
By using Sys.setenv(JAVA_HOME='C:/Program Files/Java/jre1.8.0_181') I solve the same problem for single core. But when I go parallel
library(parallel)
no_cores <- detectCores() - 1
cl <- makeCluster(no_cores)
clusterExport(cl, varlist = list("jdbcConnection", "brand3.merge.u"))
clusterEvalQ(cl, .libPaths("C:/Users/onur.boyar/Documents/R/win-library/3.5"))
clusterEvalQ(cl, library(RJDBC))
clusterEvalQ(cl, library(rJava))
parLapply(cl, 1:length(brand3.merge.u$CELL_PH_NUM), function(x) dbSendUpdate(jdbcConnection, "INSERT INTO xxnvdw.an_cust_analytics VALUES(?,?,?,?,?,?,?,?)", brand3.merge.u[x, 1], brand3.merge.u[x,2], brand3.merge.u[x,3],brand3.merge.u[x,4],brand3.merge.u[x,5],brand3.merge.u[x,6],brand3.merge.u[x,7],brand3.merge.u[x,8]))
#brand3.merge.u is my data frame that I try to write.
I get the above error and I do not know how to set my Java location for other nodes.
I want to use parLapply since it is faster than foreach. Any help would be appreciated. Thanks!
JAVA_HOME environment variable
If the problem really is with the location of Java, you could set the environment variable in your .Renviron file. It is likely located in ~/.Renviron. Add a line to that file and this will be propagated to all R session that run via your user:
JAVA_HOME='C:/Program Files/Java/jre1.8.0_181'
Alternatively, you can just add that location to your PATH environment variable.
JVM Initialization via rJava
On the other hand the error message may point to just a JVM not being initialized, which you can solve with .jinit, a minimal example:
library(parallel)
cl <- makeCluster(detectCores())
parallel::parLapply(cl, 1:5, function(x) {
rJava::.jinit()
rJava::.jnew(class = "java/lang/Integer", x)$toString()
})
Working around Java use
This was not specifically asked, but you can also work around the need for Java dependency using ODBC drivers, which for Oracle should be accessible here:
con <- DBI::dbConnect(
odbc::odbc(),
Driver = "[your driver's name]",
...
)
I would linke to call java app from PHP:
exec('LC_ALL=en_US.utf-8 java -jar /test.jar' . $filepath . ');
But always there are unsupported characters in the file path.
For example: # & ; ? * [SPACE]..., after change them to # \& ... it will be ok.
But a full list of these characters could not be find.
Any ideas to solve this problem?
Take a look at escapeshellarg() and escapeshellcmd().
They will take care of all necessary sanitation for you.
If $filepath comes from the outside (e.g. from user input), running escapeshellarg() is mandatory to prevent injections.
My problem resolved.
Useful url:
http://bugs.php.net/bug.php?id=44945
In documentation code I see some things like this:
/*
* #(#)File.java 1.142 09/04/01
what does characters like #(#) meaning?
#(#) is the character string used by the Unix what command to filter strings from binaries to list the components that were used to build that binary. For instance what java on AIX yields:
java:
23 1.4 src/bos/usr/ccs/lib/libpthreads/init.c, libpth, bos520 8/19/99 12:20:14
61 1.14 src/bos/usr/ccs/lib/libc/__threads_init.c, libcthrd, bos520 7/11/00 12:04:14
src/tools/sov/java.c, tool, asdev, 20081128 1.83.1.36
src/misc/sov/copyrght.c, core, asdev, 20081128 1.8
while `strings java | grep '#(#)' yields:
#(#)23 1.4 src/bos/usr/ccs/lib/libpthreads/init.c, libpth, bos520 8/19/99 12:20:14
#(#)61 1.14 src/bos/usr/ccs/lib/libc/__threads_init.c, libcthrd, bos520 7/11/00 12:04:14
#(#)src/tools/sov/java.c, tool, asdev, 20081128 1.83.1.36
#(#)src/misc/sov/copyrght.c, core, asdev, 20081128 1.8
#(#) was chosen as marker because it would not occur elsewhere, source code controls systems typically add a line containing this marker and the description of the file version on synchronisation, expanding keywords with values reflecting the file contents.
For instance, the comment you list would be the result of expanding the SCCS keywords %Z% %M% %R%.%L% %E% where the %Z% translates into #(#).
From (hazy) memory, that was the tag used by SCCS back in the "good old days". Given that (to my knowledge), BitKeeper uses SCCS underneath, it could be BitKeeper.
It is usually something that is added automatically by the version control system.
That construct has no special meaning in Java. It is just some text in a comment.
It looks like something that's inserted by a version control system.