How to find the JVM version from a program?

Question 1

I want to write a sample Java file in which I want to know the JVM version in which the class is running. Is there a way?

Question 2

few notes. System properties are meant for that but DO keep in mind it's a privileged operation and applets/webstart/sand boxed code will not be able to execute it (getting SecurityException). Normally you'd like to run it in similar way AccessController.doPrivileged(new PrivilegedAction<String>(...));

Question 3

@bestsss While some properties are only available to applets that are trusted: java.specification.version, java.version & java.vm.version are all available to a sand-boxed applet, or at least they were as of 1.6.0_23. See my answer for more details.

Question 4

Also a thing that may work: java -version :)

Question 5

Possible duplicate of Getting Java version at runtime

Question 6

@badp There might be many installations of Java on a system, and an application might even bundle one with itself. We can't assume whatever java -version returns was what was used to run the program.

Question 7

System.getProperty("java.version") returns what you need.

You can also use JMX if you want:

ManagementFactory.getRuntimeMXBean().getVmVersion()

Question 8

That JMX call returns the equivalent of "java.vm.version", not "java.version". These are usually (but not necessarily) the same.

Question 9

ManagementFactory.getRuntimeMXBean().getSpecVersion() may be more accurate.

Question 10

When are they different, @AlexMiller? That sounds interesting.

Question 11

Actually, I'd say they're not the same. The java.vm.version is the jvm version number, something like "25.0-b70" whereas the java.version is the normal java language version you're used to seeing "1.8.0".

Question 12

Worth noting that the Java 9 will change the returned value from this string.

Question 13

Use:

System.getProperty("java.version");

Where java.version can be replaced with one of the many other system properties related to the current Java version. Here is a table of them:

 Property Value (OpenJDK 12) Value (Oracle JRE 8u201) Value (Sun JRE 5u22) Description
------------------------------- ----------------------------------------- --------------------------------------- ---------------------------------------------------- ---------------------------------------------------------------------------------------------------------------
 java.version "12" "1.8.0_201" "1.5.0_22" Java Runtime Environment version, which may be interpreted as a Runtime.Version
 java.version.date "2019-03-19" null null Java Runtime Environment version date, in ISO-8601 YYYY-MM-DD format, which may be interpreted as a LocalDate
 java.vendor "Oracle Corporation" "Oracle Corporation" "Sun Microsystems Inc." Java Runtime Environment vendor
 java.vendor.version null null null Java vendor version
 java.vendor.url "https://java.oracle.com/" "http://java.oracle.com/" "http://java.sun.com/" Java vendor URL
 java.vendor.url.bug "https://bugreport.java.com/bugreport/" "http://bugreport.sun.com/bugreport/" "http://java.sun.com/cgi-bin/bugreport.cgi" Undocumented
 java.specification.name "Java Platform API Specification" "Java Platform API Specification" "Java Platform API Specification" Java Runtime Environment specification name
 java.specification.vendor "Oracle Corporation" "Oracle Corporation" "Sun Microsystems Inc." Java Runtime Environment specification vendor
 java.specification.version "12" "1.8" "1.5" Java Runtime Environment specification version, whose value is the feature element of the runtime version
 java.vm.name "OpenJDK 64-Bit Server VM" "Java HotSpot(TM) 64-Bit Server VM" "Java HotSpot(TM) 64-Bit Server VM" Java Virtual Machine implementation name
 java.vm.vendor "Oracle Corporation" "Oracle Corporation" "Sun Microsystems Inc." Java Virtual Machine implementation vendor
 java.vm.version "12+33" "25.201-b09" "1.5.0_22-b03" Java Virtual Machine implementation version which may be interpreted as a Runtime.Version
 java.vm.info "mixed mode, sharing" "mixed mode" "mixed mode" Undocumented
 java.vm.specification.name "Java Virtual Machine Specification" "Java Virtual Machine Specification" "Java Virtual Machine Specification" Java Virtual Machine specification name
 java.vm.specification.vendor "Oracle Corporation" "Oracle Corporation" "Sun Microsystems Inc." Java Virtual Machine specification vendor
 java.vm.specification.version "12" "1.8" "1.0" Java Virtual Machine specification version, whose value is the feature element of the runtime version
 java.runtime.name "OpenJDK Runtime Environment" "Java(TM) SE Runtime Environment" "Java(TM) 2 Runtime Environment, Standard Edition" Undocumented
 java.runtime.version "12+33" "1.8.0_201-b09" "1.5.0_22-b03" Undocumented
 java.class.version "56.0" "52.0" "49.0" Java class format version number
 jdk.debug "release" null null Undocumented
 sun.java.launcher "SUN_STANDARD" "SUN_STANDARD" "SUN_STANDARD" Undocumented
 sun.management.compiler "HotSpot 64-Bit Tiered Compilers" "HotSpot 64-Bit Tiered Compilers" "HotSpot 64-Bit Server Compiler" Undocumented

Sources:

Output of java -XshowSettings:all -version for a variety of JVM versions.
Java API Reference documentation for System.getProperties()

Question 14

It seems the java.specification.version is the best one for the job.

E.G.

java.specification.version 1.6
java.version 1.6.0_23
java.vm.version 19.0-b09
java.runtime.version 1.6.0_23-b05

Question 15

java.vm.version is null in openjdk-11-headless

Question 16

@User8461 Maybe you should raise a bug report with whoever oversees the open JDK, To be honest I've not seen much point to finding out that value. Here it is currently 25.45-b02 .. which means nothing (provides no useful information) to me.

Question 17

Simply a case of calling System.getProperty("java.version").

Question 18

Just simply call,

System.out.println(System.getProperty("java.specification.version"));
System.out.println(System.getProperty("java.runtime.version"));

Example output:

9
9+176

Question 19

Below java code returns JVM versions which are available in your current IDE

List<VirtualMachineDescriptor> descriptors = VirtualMachine.list();
 for (VirtualMachineDescriptor descriptor : descriptors) {
 System.out.println("Found JVM: " + descriptor.displayName());
 try {
 VirtualMachine vm = VirtualMachine.attach(descriptor);
 String version = vm.getSystemProperties().getProperty("java.runtime.version");
 System.out.println(" Runtime Version: " + version);
 String connectorAddress = vm.getAgentProperties().getProperty("com.sun.management.jmxremote.localConnectorAddress");
 if (connectorAddress == null) {
 connectorAddress = vm.getAgentProperties().getProperty("com.sun.management.jmxremote.localConnectorAddress");
 }
 JMXServiceURL url = new JMXServiceURL(connectorAddress);
 JMXConnector connector = JMXConnectorFactory.connect(url);
 MBeanServerConnection mbs = connector.getMBeanServerConnection();
 ObjectName threadName = new ObjectName(ManagementFactory.THREAD_MXBEAN_NAME);
 Integer threadCount = (Integer)mbs.getAttribute(threadName, "ThreadCount");
 System.out.println(" Thread count: " + threadCount);
 }
 catch (Exception e) {
 // ...
 }

output:

Found JVM: /home/.../STS IDE/sts-bundle/sts-3.7.2.RELEASE//plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar -os linux -ws gtk -arch x86_64 -showsplash -launcher /home/.../STS IDE/sts-bundle/sts-3.7.2.RELEASE/STS -name STS --launcher.library /home/.../STS IDE/sts-bundle/sts-3.7.2.RELEASE//plugins/org.eclipse.equinox.launcher.gtk.linux.x86_64_1.1.300.v20150602-1417/eclipse_1612.so -startup /home/.../STS IDE/sts-bundle/sts-3.7.2.RELEASE//plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar --launcher.overrideVmargs -exitdata 1ad000f -product org.springsource.sts.ide -vm /usr/bin/java -vmargs -Dosgi.requiredJavaVersion=1.7 -Xms40m -XX:MaxPermSize=256m -Xverify:none -Xmx1200m -jar /home/.../STS IDE/sts-bundle/sts-3.7.2.RELEASE//plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar
 Runtime Version: 1.8.0_91-b14
Found JVM: com.intellij.idea.Main
 Runtime Version: 1.8.0_91-b14
Found JVM: Test
 Runtime Version: 1.7.0_80-b15

Question 20

Depending on what one needs, the other answers can help.

In my case, they didn't. I was looking for the "fully qualified" version information of a IBM JDK.

So, the "real" answer can be: just dump all system properties and check if there is one that gives you what you are looking for.

In my case; I found that the IBM JDK knows a

Property: java.fullversion

JRE 1.8.0 IBM J9 2.8 Linux amd64-64 Compressed References 20161013_322271 (JIT enabled, AOT enabled)

J9VM - R28_Java8_SR3_20161013_1635_B322271

JIT - tr.r14.java.green_20161011_125790

GC - R28_Java8_SR3_20161013_1635_B322271_CMPRSS J9CL - 20161013_322271

Question 21

Since Java 9 we have a new static method: Runtime.version().

The object returned has interesting methods such as feature() or compareToIgnoreOptional() what might be easier to work with (e.g. Runtime.version().feature() >= 11).

Question 22

Unfortunately I couldn't find a nice list of constant fields, so we can't write Runtime.version(). compareToIgnoreOptional(Something.V11) or similar. A kinda-workaround would be to use Runtime.Version.parse("11").

Question 23

we can use the JVM runtime's class bytecode version to check against required JVM release:

This solution doesn't depend on any Enum constants etc and is backward compatible.

NOTE: This solution works irrespective of the bytecode version of the current executing class or other classes/jars in runtime classpath because the property reflects the assigned bytecode version for a given JDK release.

example: if a class is compiled at sourceCompatibility/targetCompatiblity 1.8/release level 8, but if it is executed using Java 11 JDK/runtime, then the java.class.version system property value will still be 55(Java11) though the executing class bytecode level is 52(Java8).

public class Java9Check{
 public static void main(String[] args){
 String bytecodeStr = System.getProperty("java.class.version");
 try {
 double bytecodeVal = Double.parseDouble(bytecodeStr);
 int bytecode = (int) bytecodeVal;
 // if Java 8 or below, return ExitCode(1)
 if (bytecode < 53) {
 System.out.println("Java8 or below");
 System.exit(1);
 }
 System.out.println("Java9 or above");
 } catch (NumberFormatException ignored) {}
 // proceed with normal exit, ExitCode(0)
 }
}

JDK Version Class File Version
Java 1.0 45.0
Java 1.1 45.3
Java 1.2 46.0
Java 1.3 47.0
Java 1.4 48.0
Java 5 49.0
Java 6 50.0
Java 7 51.0
Java 8 52.0
Java 9 53.0
Java 10 54.0
Java 11 55.0
Java 12 56.0
Java 13 57.0
Java 14 58.0
Java 15 59.0
Java 16 60.0
Java 17 61.0
Java 18 62.0
Java 19 63.0
Java 20 64.0
Java 21 65.0
Java 22 66.0

Question 24

Information about versions is stored as a properties of System class.

http://docs.oracle.com/javase/6/docs/api/java/lang/System.html#getProperties%28%29

Question 25

System.getProperty("sun.arch.data.model");

Java 32 Bit and 64 Bit Control

Integer vers = Integer.parseInt(System.getProperty("java.version").split("\\.")[1]);
String bitMode = System.getProperty("sun.arch.data.model").toString();
System.out.println(vers);
System.out.println(bitMode);

Output:

6
32

AlexR 116k16 gold badges137 silver badges216 bronze badges · Accepted Answer · 2011-02-24 10:10:45Z

160

System.getProperty("java.version") returns what you need.

You can also use JMX if you want:

ManagementFactory.getRuntimeMXBean().getVmVersion()

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answered Feb 24, 2011 at 10:10

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AlexR

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5 Comments

Alex Miller

Alex Miller Over a year ago

That JMX call returns the equivalent of "java.vm.version", not "java.version". These are usually (but not necessarily) the same.

2013年06月21日T15:54:06.63Z+00:00

auntyellow

auntyellow Over a year ago

ManagementFactory.getRuntimeMXBean().getSpecVersion() may be more accurate.

2014年12月09日T06:04:27.19Z+00:00

user201891

user201891 Over a year ago

When are they different, @AlexMiller? That sounds interesting.

2015年07月08日T00:26:18.57Z+00:00

Alex Miller

Alex Miller Over a year ago

Actually, I'd say they're not the same. The java.vm.version is the jvm version number, something like "25.0-b70" whereas the java.version is the normal java language version you're used to seeing "1.8.0".

2015年07月08日T02:19:52.533Z+00:00

AlBlue

AlBlue Over a year ago

Worth noting that the Java 9 will change the returned value from this string.

2016年04月20日T19:12:10.557Z+00:00

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