Java tmp dir linux

/tmp directory in Linux Android SDK

Just to tinker with it, last night I installed the Android Studio/SDK, and both during install and use, it repeatedly blew my 2Gb /tmp partition. Is there any way to tell this monster to use something other than /tmp, especially for downloading/unzipping? Fedora release 20 (Heisenbug) Thanks

This is a link to the current bug tracker for this problem (the more people that star it, the more likely it is to be fixed) issuetracker.google.com/issues/72581483

15 Answers 15

Setting -Djava.io.tmpdir=whatever didn’t work for me. I simply created $HOME/tmp/PackageOperation04 and then created a symlink from /tmp .

cd ~ mkdir -p tmp/PackageOperation04 cd /tmp ln -s $HOME/tmp/PackageOperation04 

This way the Android SDK uses my /home partition instead of /tmp for this.

Yeah, I couldn’t figure out where to tweak the VM options for the initial startup/SDK download/configure either, and I found that it would use the vmoptions for everything except downloading packages. In order to bootstrap the first startup I had to do this for both the PackageOperation01 and PackageOperation04 directories.

Folder might change to PackageOperation01 in android studio 3.0. Please check directory in /tmp for right folder name.

android-studio created in my case different folders and always ignored the already existing. If you have the same problem try Paul Ratazzi’s solution below

You can change the location of the temporary directory used by the Java Virtual Machine running Android Studio. In Android Studio 2.0 or later, select Help -> Edit Custom VM Options. This will create a copy of the installation’s vmoptions file in your own configuration directory and open it in the editor. Add the following line and restart:

where is an absolute path to a directory in a partition with enough space. If doesn’t exist, it will be created the next time Android Studio is started.

You can also edit the file directly (and need to in versions prior to 2.0), but it’s location varies depending on the platform version and possibly an environment variable setting. See Configuring Android Studio: IDE & VM Options, JDK, etc. for the details.

An alternative solution would be to increase the size of /tmp which in your case is most likely a tmpfs partition and thus easily resizable.

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How to get the temporary file path in Java

In Java, we can use System.getProperty(«java.io.tmpdir») to get the default temporary file location.

1. For Windows, the default temporary folder is %USER%\AppData\Local\Temp
2. For Linux, the default temporary folder is /tmp

1. java.io.tmpdir

Run the below Java program on a Ubuntu Linux.

 package com.mkyong.io.temp; public class TempFilePath1 < public static void main(String[] args) < String tmpdir = System.getProperty("java.io.tmpdir"); System.out.println("Temp file path: " + tmpdir); >> 

2. Create Temporary File

Alternatively, we can create a temporary file and substring the file path to get the temporary file location.

 package com.mkyong.io.temp; import java.io.IOException; import java.nio.file.FileSystems; import java.nio.file.Files; import java.nio.file.Path; public class TempFilePath2 < public static void main(String[] args) < // Java NIO try < Path temp = Files.createTempFile("", ".tmp"); String absolutePath = temp.toString(); System.out.println("Temp file : " + absolutePath); String separator = FileSystems.getDefault().getSeparator(); String tempFilePath = absolutePath .substring(0, absolutePath.lastIndexOf(separator)); System.out.println("Temp file path : " + tempFilePath); >catch (IOException e) < e.printStackTrace(); >> > 

 Temp file : /tmp/log_11536339146653799756.tmp Temp file path : /tmp 

 package com.mkyong.io.temp; import java.io.File; import java.io.IOException; public class TempFilePath3 < public static void main(String[] args) < // Java IO try < File temp = File.createTempFile("log_", ".tmp"); System.out.println("Temp file : " + temp.getAbsolutePath()); String absolutePath = temp.getAbsolutePath(); String tempFilePath = absolutePath .substring(0, absolutePath.lastIndexOf(File.separator)); System.out.println("Temp file path : " + tempFilePath); >catch (IOException e) < e.printStackTrace(); >> > 

 Temp file : /tmp/log_9219838414378386507.tmp Temp file path : /tmp 

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Creating Temporary Directories in Java

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It’s one geared specifically towards real-life production environments. Using Lightrun, you can drill down into running applications, including 3rd party dependencies, with real-time logs, snapshots, and metrics.

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Slow MySQL query performance is all too common. Of course it is. A good way to go is, naturally, a dedicated profiler that actually understands the ins and outs of MySQL.

The Jet Profiler was built for MySQL only, so it can do things like real-time query performance, focus on most used tables or most frequent queries, quickly identify performance issues and basically help you optimize your queries.

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The Kubernetes ecosystem is huge and quite complex, so it’s easy to forget about costs when trying out all of the exciting tools.

To avoid overspending on your Kubernetes cluster, definitely have a look at the free K8s cost monitoring tool from the automation platform CAST AI. You can view your costs in real time, allocate them, calculate burn rates for projects, spot anomalies or spikes, and get insightful reports you can share with your team.

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We’re looking for a new Java technical editor to help review new articles for the site.

1. Overview

Temporary directories come in handy when we need to create a set of files that we can later discard. When we create temporary directories, we can delegate to the operating system where to put them or specify ourselves where we want to place them.

In this short tutorial, we’ll learn how to create temporary directories in Java using different APIs and approaches. All the examples in this tutorial will be performed using plain Java 7+, Guava, and Apache Commons IO.

2. Delegate to the Operating System

One of the most popular approaches used to create temporary directories is to delegate the destination to the underlying operating system. The location is given by the java.io.tmpdir property, and every operating system has its own structure and cleanup routines.

In plain Java, we create a directory by specifying the prefix we want the directory to take:

String tmpdir = Files.createTempDirectory("tmpDirPrefix").toFile().getAbsolutePath(); String tmpDirsLocation = System.getProperty("java.io.tmpdir"); assertThat(tmpdir).startsWith(tmpDirsLocation);

Using Guava, the process is similar, but we can’t specify how we want to prefix our directory:

String tmpdir = Files.createTempDir().getAbsolutePath(); String tmpDirsLocation = System.getProperty("java.io.tmpdir"); assertThat(tmpdir).startsWith(tmpDirsLocation);

Apache Commons IO doesn’t provide a way to create temporary directories. It provides a wrapper to get the operating system temporary directory, and then, it’s up to us to do the rest:

String tmpDirsLocation = System.getProperty("java.io.tmpdir"); Path path = Paths.get(FileUtils.getTempDirectory().getAbsolutePath(), UUID.randomUUID().toString()); String tmpdir = Files.createDirectories(path).toFile().getAbsolutePath(); assertThat(tmpdir).startsWith(tmpDirsLocation);

In order to avoid name clashes with existing directories, we use UUID.randomUUID() to create a directory with a random name.

3. Specifying the Location

Sometimes we need to specify where we want to create our temporary directory. A good example is during a Maven build. Since we already have a “temporary” build target directory, we can make use of that directory to place temporary directories our build might need:

Path tmpdir = Files.createTempDirectory(Paths.get("target"), "tmpDirPrefix"); assertThat(tmpdir.toFile().getPath()).startsWith("target");

Both Guava and Apache Commons IO lack methods to create temporary directories at specific locations.

It’s worth noting that the target directory can be different depending on the build configuration. One way to make it bullet-proof is to pass the target directory location to the JVM running the test.

As the operating system isn’t taking care of the cleanup, we can make use of File.deleteOnExit():

This way, the file is deleted once the JVM terminates, but only if the termination is graceful.

4. Using Different File Attributes

Like any other file or directory, it’s possible to specify file attributes upon the creation of a temporary directory. So, if we want to create a temporary directory that can only be read by the user that creates it, we can specify the set of attributes that will accomplish that:

FileAttribute attrs = PosixFilePermissions.asFileAttribute( PosixFilePermissions.fromString("r--------")); Path tmpdir = Files.createTempDirectory(Paths.get("target"), "tmpDirPrefix", attrs); assertThat(tmpdir.toFile().getPath()).startsWith("target"); assertThat(tmpdir.toFile().canWrite()).isFalse();

As expected, Guava and Apache Commons IO do not provide a way to specify the attributes when creating temporary directories.

It’s also worth noting that the previous example assumes we are under a Posix Compliant Filesystem such as Unix or macOS.

More information about file attributes can be found in our Guide to NIO2 File Attribute APIs.

5. Conclusion

In this short tutorial, we explored how to create temporary directories in plain Java 7+, Guava, and Apache Commons IO. We saw that plain Java is the most flexible way to create temporary directories as it offers a wider range of possibilities while keeping the verbosity to a minimum.

As usual, all the source code for this tutorial is available over on GitHub.

Slow MySQL query performance is all too common. Of course it is. A good way to go is, naturally, a dedicated profiler that actually understands the ins and outs of MySQL.

The Jet Profiler was built for MySQL only, so it can do things like real-time query performance, focus on most used tables or most frequent queries, quickly identify performance issues and basically help you optimize your queries.

Critically, it has very minimal impact on your server’s performance, with most of the profiling work done separately — so it needs no server changes, agents or separate services.

Basically, you install the desktop application, connect to your MySQL server, hit the record button, and you’ll have results within minutes:

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Linux command to get current value of java.io.tmpdir

I need a Linux command to get current value of java.io.tmpdir Also can you tell me the command to get all the system propeties.

4 Answers 4

JDK provides tools with which you can achieve your goal. Using the specified command, you can display the value of a system variable java.io.tmpdir .

The is the number of the java process for which you want to display the value of the system variable. Id of the java process you can get by using the jps tool, which list all java processes running on your machine.

To see all system variables of the java process, please use this command

All JDK tools are located in $JAVA_HOME/bin directory.

java.io.tmpdir is one of java system properties, so its value exists only inside jvm. To find out what is the value of java.io.tmpdir property you can also write a simple program in java. It may look something like this piece of code:

public class JSystemProperties < public static void main(String[] args) < System.getProperties().list(System.out); >> 

The code above will print all java system properties, but you can modify this to print only one system property with name you pass through args array (using System.getProperty(key) method). After you compile this class you can create script (which will run compiled java class) that can be treated as Linux command to get current values of java system properties.

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