Package com.install4j.api

Class JVMSelector

java.lang.Object

com.install4j.api.JVMSelector

public class JVMSelector
extends Object

With this class, you can retrieve the installed JVMs on Windows, Linux and Unix systems. Additionally, you can set the preferred VM for your application.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	JVMSelector.JVMLocation	The interface providing information about a JVM.

Method Summary

Modifier and Type	Method	Description
static JVMSelector.JVMLocation	getJVMLocation(File javaHome, String minVersion, String maxVersion, boolean jdkOnly)	Checks if this directory contains a JVM with the specified parameters and returns the location object.
static JVMSelector.JVMLocation[]	getJVMLocations()	Returns JVMs found in standard locations.
static JVMSelector.JVMLocation[]	getJVMLocations(String minVersion, String maxVersion, boolean jdkOnly, File[] additionalLocations)	Returns JVMs found in standard locations with the given version requirements.
static void	setPreferredJVM(String javaHome)	Set the preferred JRE/JDK for your application.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

getJVMLocations

public static JVMSelector.JVMLocation[] getJVMLocations()

Returns JVMs found in standard locations. On Windows the registry is used to get the JVMs. On Linux/Unix and macOS this method searches the usual locations for JVMs. Please be aware that this method can take some time on Linux/Unix as it executes java to gather version information.

Returns:

an array of JVMLocation objects. See this class for more detail.

getJVMLocations

public static JVMSelector.JVMLocation[] getJVMLocations(String minVersion,
 String maxVersion,
 boolean jdkOnly,
 File[] additionalLocations)

Returns JVMs found in standard locations with the given version requirements. On Windows the registry is used to get the JVMs. On Linux/Unix and macOS this methods searches the usual locations for JVMs. Please be aware that this method can take some time on Linux/Unix as it executes java to gather version information.

Parameters:

minVersion - the minimum java version

maxVersion - the maximum java version

jdkOnly - only JDKs

additionalLocations - additional locations that should be tested for JVMs

Returns:

an array of JVMLocation objects. See this class for more detail.

getJVMLocation

public static JVMSelector.JVMLocation getJVMLocation(File javaHome,
 String minVersion,
 String maxVersion,
 boolean jdkOnly)

Checks if this directory contains a JVM with the specified parameters and returns the location object. The versions can be empty Strings if there should be no restriction.

Parameters:

javaHome - the directory to check

minVersion - the minimum java version

maxVersion - the maximum java version

jdkOnly - only JDKs

Returns:

a JVMLocation objects or null. See this class for more detail.

setPreferredJVM

public static void setPreferredJVM(String javaHome)

Set the preferred JRE/JDK for your application. As long as this JRE/JDK exists and fulfills the version requirement of your application it will be used. This method has no effect on macOS.

Parameters:

javaHome - the base directory of the JDK/JRE.