de.ipcon.tools

Class JavaVersion

java.lang.Object

de.ipcon.tools.JavaVersion

public class JavaVersion
extends java.lang.Object

Provides utility methods for retrieving and analyzing Java version information.

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	isHotspot Flag indicating if the virtual machine is HotSpot.
static boolean	isJ9 Flag indicating if the virtual machine is J9.
static org.apache.log4j.Logger	log Logger for the JavaVersion class.
static int	major The major version number of the Java runtime environment.
static int	minor The minor version number of the Java runtime environment.
static java.lang.String	versionString The version string of the Java runtime environment.
static int	VM_IBM_J9 Constant representing the IBM J9 virtual machine.
static int	VM_OPENJDK_HOTSPOT Constant representing the OpenJDK HotSpot virtual machine.
static int	VM_OPENJDK_J9 Constant representing the OpenJDK J9 virtual machine.
static int	VM_ORACLE_HOTSPOT Constant representing the Oracle HotSpot virtual machine.
static int	VM_UNKNOWN Constant representing an unknown virtual machine.
static int	vmImpl The virtual machine implementation type.
static java.lang.String[]	vmTitles Array of virtual machine titles corresponding to the VM constants.

Constructor Summary

Constructors

Constructor and Description
JavaVersion()

Method Summary

Modifier and Type	Method and Description
static boolean	atLeast(int reqMajor) Checks if the Java version is at least the specified version.
static boolean	atLeast(int reqMajor, int reqMinor) Checks if the Java version is at least the specified version.
static boolean	atLeast(int reqMajor, int reqMinor, int needsVmImpl) Checks if the Java version is at least the specified version.
static boolean	atLeast(int reqMajor, int reqMinor, int needsVmImpl, boolean needsHotspotImpl) Checks if the Java version is at least the specified version.
static boolean	is(int reqMajor) Checks if the Java version matches the specified version.
static boolean	is(int reqMajor, int reqMinor) Checks if the Java version matches the specified version.
static boolean	is(int reqMajor, int reqMinor, int needsVmImpl) Checks if the Java version matches the specified version.
static boolean	is(int reqMajor, int reqMinor, int needsVmImpl, boolean needsHotspotImpl) Checks if the Java version matches the specified version.
static boolean	needsExplicitGCCallToCompressHeap() Determines whether an explicit garbage collection call is needed to compress the heap.

Methods inherited from class java.lang.Object

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

Field Detail

log

public static final org.apache.log4j.Logger log

Logger for the JavaVersion class.

VM_UNKNOWN

public static final int VM_UNKNOWN

Constant representing an unknown virtual machine.

See Also:

Constant Field Values

VM_ORACLE_HOTSPOT

public static final int VM_ORACLE_HOTSPOT

Constant representing the Oracle HotSpot virtual machine.

See Also:

Constant Field Values

VM_IBM_J9

public static final int VM_IBM_J9

Constant representing the IBM J9 virtual machine.

See Also:

Constant Field Values

VM_OPENJDK_HOTSPOT

public static final int VM_OPENJDK_HOTSPOT

Constant representing the OpenJDK HotSpot virtual machine.

See Also:

Constant Field Values

VM_OPENJDK_J9

public static final int VM_OPENJDK_J9

Constant representing the OpenJDK J9 virtual machine.

See Also:

Constant Field Values

vmTitles

public static final java.lang.String[] vmTitles

Array of virtual machine titles corresponding to the VM constants.

versionString

public static java.lang.String versionString

The version string of the Java runtime environment.

major

public static int major

The major version number of the Java runtime environment.

minor

public static int minor

The minor version number of the Java runtime environment.

vmImpl

public static int vmImpl

The virtual machine implementation type.

isHotspot

public static boolean isHotspot

Flag indicating if the virtual machine is HotSpot.

isJ9

public static boolean isJ9

Flag indicating if the virtual machine is J9.

Constructor Detail

JavaVersion

public JavaVersion()

Method Detail

atLeast

public static boolean atLeast(int reqMajor)

Checks if the Java version is at least the specified version.

Parameters:

reqMajor - The required major version.

Returns:

True if the Java version meets the specified criteria, false otherwise.

atLeast

public static boolean atLeast(int reqMajor,
                              int reqMinor)

Checks if the Java version is at least the specified version.

Parameters:

reqMajor - The required major version.

reqMinor - The required minor version.

Returns:

True if the Java version meets the specified criteria, false otherwise.

atLeast

public static boolean atLeast(int reqMajor,
                              int reqMinor,
                              int needsVmImpl)

Checks if the Java version is at least the specified version.

Parameters:

reqMajor - The required major version.

reqMinor - The required minor version.

needsVmImpl - The required virtual machine implementation type.

Returns:

True if the Java version meets the specified criteria, false otherwise.

atLeast

public static boolean atLeast(int reqMajor,
                              int reqMinor,
                              int needsVmImpl,
                              boolean needsHotspotImpl)

Checks if the Java version is at least the specified version.

Parameters:

reqMajor - The required major version.

reqMinor - The required minor version.

needsVmImpl - The required virtual machine implementation type.

needsHotspotImpl - Indicates whether HotSpot implementation is required.

Returns:

True if the Java version meets the specified criteria, false otherwise.

is

public static boolean is(int reqMajor)

Checks if the Java version matches the specified version.

Parameters:

reqMajor - The required major version.

Returns:

True if the Java version matches the specified criteria, false otherwise.

is

public static boolean is(int reqMajor,
                         int reqMinor)

Checks if the Java version matches the specified version.

Parameters:

reqMajor - The required major version.

reqMinor - The required minor version.

Returns:

True if the Java version matches the specified criteria, false otherwise.

is

public static boolean is(int reqMajor,
                         int reqMinor,
                         int needsVmImpl)

Checks if the Java version matches the specified version.

Parameters:

reqMajor - The required major version.

reqMinor - The required minor version.

needsVmImpl - The required virtual machine implementation type.

Returns:

True if the Java version matches the specified criteria, false otherwise.

is

public static boolean is(int reqMajor,
                         int reqMinor,
                         int needsVmImpl,
                         boolean needsHotspotImpl)

Checks if the Java version matches the specified version.

Parameters:

reqMajor - The required major version.

reqMinor - The required minor version.

needsVmImpl - The required virtual machine implementation type.

needsHotspotImpl - Indicates whether HotSpot implementation is required.

Returns:

True if the Java version matches the specified criteria, false otherwise.

needsExplicitGCCallToCompressHeap

public static boolean needsExplicitGCCallToCompressHeap()

Determines whether an explicit garbage collection call is needed to compress the heap.

Returns:

True if an explicit garbage collection call is needed, false otherwise.