Extracting MSI files from the Java install prompted me to work up a method to keep Java updates in our WPKG share current. So here it is. Probably not the best Python, but it's functional (Python 2, should be adaptable to Python 3 easily). If you use a different deployment method (other than WPKG), you'll obviously need to adjust update_java_packages accordingly.

Features

• Checks for latest Java 8 version from Javascript embedded in https://java.com/en/download/installed8.jsp

• Stores JRE and JDK license acceptance in cookie before downloading. Of course you've agreed to it in the past.

• Downloads latest JRE and JDK, runs installers long enough to copy extracted MSI and CAB files to destination folder.

• Updates WPKG package files with new update numbers.

• Records latest update downloaded, so the script can exit quickly if there's no new updates.

Scripts and support files stored in a single folder:

Win32 build of wget.exe

Most likely downloaded from https://eternallybored.org/misc/wget/.

update-java.py

#!/usr/bin/env python
from string import Template
from datetime import datetime, timedelta
import subprocess
import os
import glob
import shutil
import time

def unix_time(dt):
    epoch = datetime.utcfromtimestamp(0)
    return int((dt - epoch).total_seconds())

def make_cookies(cookies):
    cookieTemplate = Template('.${domain}\t${allmachines}\t${path}\t${secure}\t${expiration}\t${name}\t${value}\n')
    tomorrow = unix_time(datetime.now() + timedelta(days=1))
    d = dict(
        domain = 'oracle.com',
        allmachines = 'TRUE',
        path = '/',
        secure = 'FALSE',
        expiration = tomorrow,
        name = 'oraclelicense',
        value = 'accept-securebackup-cookie'
    )
    cookieString = cookieTemplate.safe_substitute(d)
    with open(cookies,'w') as f:
        f.write(cookieString)

def find_latest_update(version):
    versionUrl = Template("http://java.com/en/download/installed${version}.jsp")
    url = versionUrl.safe_substitute(version=version)
    output = subprocess.check_output(["wget", "-qO-", url])
    tagLine = Template("latest${version}Version").safe_substitute(version=version)
    for line in output.split('\n'):
        if tagLine in line:
            #print line
            (_, versionString, _) = line.split("'")
            # print versionString # 1.8.0_101
            (_, update) = versionString.split("_")
            # print update # 101
            return int(update)

def download_java(kinds, version, update, cookies):
    site = "http://download.oracle.com/otn-pub/java/jdk"
    b = 13 # not sure how often this changes
    archList = ["windows-x64", "windows-i586"]
    urlTemplate = Template("${site}/${version}u${update}-b${b}/${package}-${version}u${update}-${arch}.exe")
    for arch in archList:
        for package in kinds:
            d = dict(
                site = site,
                package = package,
                version = version,
                update = update,
                b = b,
                arch = arch
            )
            url = urlTemplate.safe_substitute(d)
            print "Downloading %s" % (url)
            cookieFlag = "--load-cookies=%s" % (cookies)
            subprocess.call(["wget", "-q", cookieFlag, url],
                            cwd = os.getcwd())

def copy_java_contents(kinds, version, update, msiDestination):
    # For each executable with correct version and update
    patternTemplate=Template("${kind}-${version}u${update}-windows-*.exe")
    for kind in kinds:
        d = dict(
            kind = kind,
            version = version,
            update = update
        )
        pattern = patternTemplate.safe_substitute(d)
        olddir = os.getcwd()
        for file in glob.glob(pattern):
            print file
            # - Make a directory in wpkg/software
            (_, _, _, archexe) = file.split("-")
            if archexe=="i586.exe":
                arch = "x86"
            elif archexe=="x64.exe":
                arch = "x64"
            path = msiDestination + (r'\%s\%d\%d-%s '[:-1] % (kind,
                                                              version,
                                                              update,
                                                              arch))
            print "Will makedirs(%s) if needed" % (path)
            if not os.path.isdir(path):
                os.makedirs(path, mode = 0755)
            # - Run the executable to extract contents to temp
            print "Starting %s" % (file)
            proc = subprocess.Popen([file], shell=False)
            print "Started %s as %s" % (file, proc)
            # - Copy contents to wpkg directory
            extract_parent = os.path.join(os.environ['USERPROFILE'], 'Appdata',
                                          'LocalLow', 'Oracle', 'Java')
            print "Chccking for extract parent directory %s..." % (extract_parent),
            while not os.path.isdir(extract_parent):
                time.sleep(1)
            os.chdir(extract_parent)
            print "done."
            if arch=="x64":
                tempFolder = "%s1.%d.0_%d_%s" % (kind, version, update, arch)
            else:
                tempFolder = "%s1.%d.0_%d" % (kind, version, update)
            print "Checking for extract directory...",
            while not os.path.isdir(tempFolder):
                time.sleep(1)
            os.chdir(tempFolder)
            print "done."
            print "Sleeping for 10 seconds...",
            time.sleep(10)
            print "done."
            # - Kill the executable
            subprocess.call(['taskkill', '/F', '/T', '/PID', str(proc.pid)])
            print "Copying files...",
            for f in glob.glob("*.msi"):
                shutil.copy(f,path)
            for f in glob.glob("*.cab"):
                shutil.copy(f,path)
            print "done."
            os.chdir('..')
            # - Remove contents from temp
            shutil.rmtree(tempFolder)
            os.chdir(olddir)

def update_java_packages(kinds, version, update, wpkgRoot, branches):
    for kind in kinds:
        for branch in branches:
            sourceXML = "%s-%d.xml" % (kind, version)
            with open(sourceXML) as templateXML:
                lines=templateXML.readlines()
            template = Template( ''.join(lines) )
            d=dict(update=update)
            targetXML = os.path.join(wpkgRoot,branch,'packages',sourceXML)
            with open(targetXML,'w') as packageXML:
                packageXML.writelines(template.safe_substitute(d))

def check_local_update(msiDestination, version):
    localfile = os.path.join(msiDestination, 'jdk', str(version),
                             'localVersion.txt')

    try:
        with open(localfile, 'r') as f:
            lines = f.readlines()
            update = int(lines[0])
    except IOError:
        update = 0
    return int(update)

def write_local_update(msiDestination, version, update):
    localVersionFile = os.path.join(msiDestination, 'jdk', str(version),
                                    'localVersion.txt')
    with open(localVersionFile, 'w') as f:
        f.write(str(update))

if __name__ == "__main__":
    version = 8
    cookies = 'cookies.txt'
    kinds = ["jdk", "jre"]
    #wpkgRoot = r'\\some.server.fqdn\wpkg '[:-1]
    wpkgRoot = r'c:\users\someuser\desktop\wpkg-tmp '[:-1]
    msiDestination = wpkgRoot+r'\software '[:-1]
    branches = [ 'dev', 'stable' ]

    print "Checking for latest update to Java %d" % (version)
    update = find_latest_update(version = version)
    print "It's update %s" % (update)
    localUpdate = check_local_update(msiDestination = msiDestination,
                                     version = version)
    if localUpdate < update:
        print "Local copy (%d) is out of date." % (localUpdate)
        print "Making cookies"
        make_cookies(cookies)
        download_java(kinds = kinds,
                      version = version,
                      update = update,
                      cookies = cookies)
        copy_java_contents(kinds = kinds,
                           version = version,
                           update = update,
                           msiDestination = msiDestination)
        update_java_packages(kinds = kinds,
                             version = version,
                             update = update,
                             wpkgRoot = wpkgRoot,
                             branches = branches)
        write_local_update(msiDestination = msiDestination,
                           version = version, update = update)
    else:
        print "Local copy (%d) is current." % (localUpdate)

jdk-8.xml

<!--
Automatically generated from update-java.py and software\jdk\jdk-8.xml template file.

Do not edit packages\jdk-8.xml manually.
-->
<!-- From http://wpkg.org/Java -->
<!-- See jre-6.xml for instructions -->

<packages>
  <package id='jdk-8' name='Java Development Kit 8' priority='548' reboot='postponed' revision='%update%'>
    <variable name='version' value='8' />
    <variable name='update' value='${update}' />

    <variable name='uninstall_name' value='Java SE Development Kit %version% Update %update% (64-bit)' architecture='x64' />
    <variable name='uninstall_name' value='Java SE Development Kit %version% Update %update%' architecture='x86' />
    <check condition='exists' path='%uninstall_name%' type='uninstall' />
    <variable architecture="x64" name="source" value="%SOFTWARE%\jdk\8\%update%-x64" />
    <variable architecture="x86" name="source" value="%SOFTWARE%\jdk\8\%update%-x86" />
    
    <install cmd='taskkill /f /im jqs.exe /im iexplore.exe /im firefox.exe'>
      <exit code='0' />
      <exit code='1' />
      <exit code='128' />
    </install>
    <install cmd='msiexec /qn /i "%source%\jdk1.%version%.0_%update%.msi" JU=0 JAVAUPDATE=0 AUTOUPDATECHECK=0 RebootYesNo=No WEB_JAVA=1 INSTALLDIR="%PROGRAMFILES%\Java\JDK\"' />
    <upgrade include='install' />
    <remove cmd='msiexec /qn /x{64A3A4F4-B792-11D6-A78A-00B0D01%version%0%update%0}'>
      <exit code='1605' />
    </remove>
  </package>
</packages>

jre-8.xml

<!--
Automatically generated from update-java.py and software\jdk\jre-8.xml template file.

Do not edit packages\jre-8.xml manually.
-->
<!-- From http://wpkg.org/Java -->
<!-- See jre-6.xml for instructions -->

<packages>
  <package id='jre-8' name='Java Runtime Environment 8' priority='879' reboot='postponed' revision='%update%'>
    <variable name='version' value='8' />
    <variable name='update' value='${update}' />

    <variable name='uninstall_name' value='Java %version% Update %update%'/>
    <check condition='exists' path='%uninstall_name%' type='uninstall' />
    <variable name="source" value="%SOFTWARE%\jre\8\%update%-x86" />
    <variable architecture="x64" name="dest" value="%PROGRAMFILES(x86)%\Java\JDK" />
    <variable architecture="x86" name="dest" value="%PROGRAMFILES%\Java\JDK" />
    <install cmd='taskkill /f /im jqs.exe /im iexplore.exe /im firefox.exe'>
      <exit code='0' />
      <exit code='1' />
      <exit code='128' />
    </install>
    <install cmd='msiexec /qn /i "%source%\jre1.%version%.0_%update%.msi" JU=0 JAVAUPDATE=0 AUTOUPDATECHECK=0 RebootYesNo=No WEB_JAVA=1 INSTALLDIR="%DEST%"' />
    <upgrade include='install' />
    <remove cmd='msiexec /qn /x{26A24AE4-039D-4CA4-87B4-2F8321%version%0%update%F0}'>
      <exit code='1605' />
    </remove>
  </package>
  <package id='jre-8-x64' name='Java Runtime Environment 8 (64-bit)' priority='878' reboot='postponed' revision='%update%'>
    <variable name='version' value='8' />
    <variable name='update' value='${update}' />

    <variable name='uninstall_name' value='Java %version% Update %update% (64-bit)' architecture='x64' />
    <check condition='exists' path='%uninstall_name%' type='uninstall' />
    <variable architecture="x64" name="source" value="%SOFTWARE%\jre\8\%update%-x64" />
    <variable architecture="x64" name="dest" value="%PROGRAMFILES%\Java\JDK" />
    
    <install cmd='taskkill /f /im jqs.exe /im iexplore.exe /im firefox.exe'>
      <exit code='0' />
      <exit code='1' />
      <exit code='128' />
    </install>
    <install cmd='msiexec /qn /i "%source%\jre1.%version%.0_%update%.msi" JU=0 JAVAUPDATE=0 AUTOUPDATECHECK=0 RebootYesNo=No WEB_JAVA=1 INSTALLDIR="%DEST%"' />
    <upgrade include='install' />
    <remove cmd='msiexec /qn /X{26A24AE4-039D-4CA4-87B4-2F8641%version%0%update%F0}'>
      <exit code='1605' />
    </remove>
  </package>
</packages>

Usage:

From a command prompt in the folder containing the support files:

C:\path\to\folder>update-java.py
Checking for latest update to Java 8
It's update 101
Local copy (0) is out of date.
Making cookies
Downloading http://download.oracle.com/otn-pub/java/jdk/8u101-b13/jdk-8u101-windows-x64.exe
...
Chccking for extract parent directory C:\Users\someuser\Appdata\LocalLow\Oracle\Java... done.
Checking for extract directory... done.
Sleeping for 10 seconds... done.
SUCCESS: The process with PID 4144 (child process of PID 2664) has been terminated.
SUCCESS: The process with PID 2664 (child process of PID 2240) has been terminated.
Copying files... done.

C:\path\to\folder>update-java.py
Checking for latest update to Java 8
It's update 101

I am only coding in Python. Do I need JDK or any java related installation if I am using Python?