Java check latest version programmatically

Question

Goal: check java\'s version on a machine (I can get this from java -version). Compare it with latest available from java website

I woul

Answer 1

To get all system variables

Properties properties = System.getProperties();
System.out.println(properties);

Sample output, this might be different in your system depending on your OS and Java JDK/JRE version.

{
    java.runtime.name = Java(TM) SE Runtime Environment,
    sun.boot.library.path = C:\Program Files\Java\jdk1.8.0_31\jre\bin,
    java.vm.version = 25.31-b07,
    java.vm.vendor = Oracle Corporation,
    java.vendor.url = http://java.oracle.com/,
    path.separator = ;,
    idea.launcher.port = 7534,
    java.vm.name = Java HotSpot(TM) 64-Bit Server VM,
    file.encoding.pkg = sun.io,
    user.country = NP,
    user.script = ,
    sun.java.launcher = SUN_STANDARD,
    sun.os.patch.level = ,
    java.vm.specification.name = Java Virtual Machine Specification,
    user.dir = C:\Users\...\roid,
    java.runtime.version = 1.8.0_31-b13,
    java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironment,
    java.endorsed.dirs = C:\Program Files\Java\jdk1.8.0_31\jre\lib\endorsed,
    os.arch = amd64,
    java.io.tmpdir = C:\Windows\TEMP\,
    line.separator = ,
    java.vm.specification.vendor = Oracle Corporation,
    user.variant = ,
    os.name = Windows 8.1,
    sun.jnu.encoding = Cp1252,
    java.library.path = C:\Program...roid,
    java.specification.name = Java Platform API Specification,
    java.class.version = 52.0,
    sun.management.compiler = HotSpot 64-Bit Tiered Compilers,
    os.version = 6.3,
    user.home = C:\Users\Xxx,
    user.timezone = Asia/Kathmandu,
    java.awt.printerjob = sun.awt.windows.WPrinterJob,
    file.encoding = UTF-8,
    idea.launcher.bin.path = C:\Program Files (x86)\xxx\bin,
    java.specification.version = 1.8,
    java.class.path = C:\Program Files\Java\jdk1.8.0_31\jre\lib\charsets.jar;...,
    user.name = Xxx,
    java.vm.specification.version = 1.8,
    sun.java.command = com.xxxx.ameras,
    java.home = C:\Program Files\Java\jdk1.8.0_31\jre,
    sun.arch.data.model = 64,
    user.language = en,
    java.specification.vendor = Oracle Corporation,
    awt.toolkit = sun.awt.windows.WToolkit,
    java.vm.info = mixed mode,
    java.version = 1.8.0_31,
    java.ext.dirs = C:\Program Files\Java\jdk1.8.0_31\jre\lib\ext;...,
    java.vendor = Oracle Corporation,
    file.separator = \,
    java.vendor.url.bug = http://bugreport.sun.com/bugreport/,
    sun.io.unicode.encoding = UnicodeLittle,
    sun.cpu.endian = little,
    sun.desktop = windows,
    sun.cpu.isalist = amd64
}

Retrive only specific variable

String javaVersion = System.getProperty("java.version");
System.out.println(javaVersion);

Output

1.8.0_31