Goal: check java's version on a machine (I can get this from java -version). Compare it with latest available from java website
I would like to know if there is any way I can check for latest Java releases assuming that I have JRE/JDK installed on a machine.
If I can do this through Java itself, my solution would become platform independent. I could use java.net.URL class to send a request to Java website and get the HTML, however the response would be dynamic as Oracle can change their website and styles and possibly will have maintenance issues in long run.
I have looked at javatester.org, but I would not want it through an applet but through command line (which I can add to a script).
Through javacpl.exe, I can schedule periodic checks, but I would like to do it on demand.
-
1"but through command line"? Which command line? You want a bash script for it, or a Windows batch script, or whatever? Please be more specific.gexicide– gexicide2012年10月18日 10:40:09 +00:00Commented Oct 18, 2012 at 10:40
-
I dont understand. You want this only for your local machine or you want a script for updating computers on the ethernet ?Alexander.Iljushkin– Alexander.Iljushkin2012年10月18日 10:42:57 +00:00Commented Oct 18, 2012 at 10:42
-
@gexicide I wanted to know if there is any way I can do this through java itself to make it platform independent. For now, I'm looking for windows only. So windows batch script can serve the purpose for now.Chris– Chris2012年10月18日 10:45:07 +00:00Commented Oct 18, 2012 at 10:45
-
Do you mean this?Piotr Gwiazda– Piotr Gwiazda2012年10月18日 10:46:18 +00:00Commented Oct 18, 2012 at 10:46
-
@AutoCoder I want to write a script which when executed in a machine does this work. Network adminstration is not the part of my question. For now I want it to run from my local machineChris– Chris2012年10月18日 10:46:57 +00:00Commented Oct 18, 2012 at 10:46
9 Answers 9
The answer is actually quite simple. http://java.com/en/download/testjava.jsp issues a request to http://java.com/applet/JreCurrentVersion2.txt. That file currently contains a single version number: '1.7.0_11'...which is the latest and greatest, indeed.
Java code example
try (BufferedReader br = new BufferedReader(new InputStreamReader(new URL(
"http://java.com/applet/JreCurrentVersion2.txt").openStream()))) {
String fullVersion = br.readLine();
String version = fullVersion.split("_")[0];
String revision = fullVersion.split("_")[1];
System.out.println("Version " + version + " revision " + revision);
} catch (IOException e) {
// handle properly
}
Update 2014年03月20日
Eventhough Java 8 was recently released http://java.com/applet/JreCurrentVersion2.txt currently still returns 1.7.0_51.
Update 2016年07月13日
Looks like we need to come back to this every few months... Currently you need to scan http://java.com/en/download/installed8.jsp for a JavaScript variable latest8Version. So, you could run curl -s https://java.com/en/download/installed8.jsp | grep latest8Version.
Update 2018年08月19日
http://javadl-esd-secure.oracle.com/update/baseline.version is another hot spot as mentioned in some other answer.
2 Comments
An URL very similar to the now defunct "JreCurrentVersion2.txt":
http://javadl-esd-secure.oracle.com/update/baseline.version
The contents of the link look like this:
1.8.0_111
1.7.0_121
1.6.0_131
1.5.0_99
1.4.2_43
You can easily parse the contents to find the latest JRE versions.
4 Comments
UPDATE: I don't recommend this method because this JRE is the one that has the Ask.com toolbar. You're better off downloading it yourself and distributing it yourself.
The jusched.exe program accesses the following URL to find out what versions are available. I think it's less likely to change because jusched is installed on millions of computers.
https://javadl-esd-secure.oracle.com/update/1.7.0/map-m-1.7.0.xml
Here is a snippet of what it returns for me:
<?xml version="1.0" encoding="ISO-8859-1" standalone="yes" ?>
<java-update-map version="1.0">
<mapping>
<version>1.7.0_17</version>
<url>https://javadl-esd-secure.oracle.com/update/1.7.0/au-descriptor-1.7.0_25-b17.xml</url>
</mapping>
<mapping>
<version>1.7.0_21</version>
<url>https://javadl-esd-secure.oracle.com/update/1.7.0/au-descriptor-1.7.0_25-b17.xml</url>
</mapping>
</java-update-map>
To get the actual version that it is pointing to you have to fetch the above URL. Here is another snippet of what this XML looks like:
xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- XML file to be staged anywhere, and pointed to by map.xml file -->
<java-update>
<information version="1.0" xml:lang="en">
<caption>Java Update - Update Available</caption>
<title>Java Update Available</title>
<description>Java 7 Update 25 is ready to install. Installing Java 7 Update 25 might uninstall the latest Java 6 from your system. Click the Install button to update Java now. If you wish to update Java later, click the Later button.</description>
<moreinfo>http://java.com/moreinfolink</moreinfo>
<AlertTitle>Java Update Available</AlertTitle>
<AlertText>A new version of Java is ready to be installed.</AlertText>
<moreinfotxt>More information...</moreinfotxt>
<url>http://javadl.sun.com/webapps/download/GetFile/1.7.0_25-b17/windows-i586/jre-7u25-windows-i586-iftw.exe</url>
<version>1.7.0_25-b17</version>
<post-status>https://nometrics.java.com</post-status>
<cntry-lookup>http://rps-svcs.sun.com/services/countrylookup</cntry-lookup>
<predownload></predownload>
<options>/installmethod=jau FAMILYUPGRADE=1 SPWEB=http://javadl-esd.sun.com/update/1.7.0/sp-1.7.0_25-b17</options>
<urlinfo>24595ec7f861bc67e572f1e4ad3992441335e1a7</urlinfo>
</information>
</java-update>
The version tag contains the full version number.
1 Comment
You could parse the Java SE Downloads page to extract the Java versions.
That way, you get the version of both JDK6 and JDK7, which allows you to test your particular JDK (6 or 7) against the latest Oracle one.
(As opposed to the Free Java Download page, which only lists the JDK7)
Her is a crude script in Go, which you can compile on Windows, Unix, MacOs into a single independent executable, and use within a command line or a script:
package main
import (
"bytes"
"encoding/xml"
"fmt"
"io/ioutil"
"net/http"
"os/exec"
"regexp"
)
type Jdk struct {
Url string
Ver string
update string
}
func main() {
resp, err := http.Get("http://www.oracle.com/technetwork/java/javase/downloads/index.html")
if err != nil {
fmt.Printf("Error on http Get: %v\n", err)
return
}
bodyb, err := ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Printf("QueriesForOwner: error in ReadAll: %v\n", err)
return
}
br := bytes.NewBuffer(bodyb)
jdkre, err := regexp.Compile(`h3[^\r\n]+(/technetwork/java/javase/downloads/(jdk(?:6|7)(?:u(\d+))?)-downloads-\d+\.html)`)
if err != nil {
fmt.Printf("extract: error in regexp compilation: %v\n", err)
return
}
jdks := jdkre.FindAllSubmatch(br.Bytes(), -1)
jdk7 := Jdk{string(jdks[0][4]), string(jdks[0][5]), string(jdks[0][6])}
jdk6 := Jdk{string(jdks[1][7]), string(jdks[1][8]), string(jdks[1][9])}
fmt.Printf("Jdk7: %v\nJdk6: %v\n", jdk7, jdk6)
jver, err := exec.Command("java", "-version").CombinedOutput()
if err != nil {
fmt.Printf("*ExitError from java -version:", err)
return
}
fmt.Println("JVer: '", string(jver), "'")
jverre, err := regexp.Compile(`1.(\d).\d(?:_(\d+))"`)
jvers := jverre.FindSubmatch(jver)
jj := string(jvers[0])
jv := string(jvers[1])
ju := string(jvers[2])
jdk := jdk6
if jv == "7" {
jdk = jdk7
}
if jdk.update != ju {
fmt.Println("Local JDK *NOT* up-to-date: you have ", jj, ", Oracle has ", jdk.Ver)
} else {
fmt.Println("Local JDK *up-to-date*: you have ", jj, ", equals to Oracle, which has", jdk.Ver)
}
}
Again, this is a crude script, oriented toward JDK, and you would need to adapt it to your specific need, making its output and exit status match what you need for your script.
On my (PC) workstation, it returns:
Jdk7: {/technetwork/java/javase/downloads/jdk7u9-downloads-1859576.html jdk7u9 9}
Jdk6: {/technetwork/java/javase/downloads/jdk6u37-downloads-1859587.html jdk6u37 37}
JVer: ' java version "1.6.0_31"
Java(TM) SE Runtime Environment (build 1.6.0_31-b05)
Java HotSpot(TM) Client VM (build 20.6-b01, mixed mode, sharing)
'
Local JDK *NOT* up-to-date: you have 1.6.0_31" , Oracle has jdk6u37
I don't know what information you are exactly looking for, but you can get some version information using
System.getProperty("java.version");
If this is not what you're looking for, check the other available properties here: http://docs.oracle.com/javase/6/docs/api/java/lang/System.html#getProperties()
As for the latest available version, I guess you'd have to parse this site manually: http://java.com/en/download/index.jsp
The latest version is on there, currently it's
Version 7 Update 9
You write that this is not what you want because "Oracle can change their website and styles". However, you want to find out the latest version of Java by accessing their service (website in this case). As long as you're not paying for this, they have no obligation to you, and can change the service whenever they want without your consent. And even when you're a paying customer, the best you can hope for is that they will inform you of upcoming changes, and your maintenance issues will remain.
Remember, it's THEIR service you want to use.
2 Comments
System.getProperty("java.version"); gives me the installed version of java.I have solved a similar issue some time ago with this groovy script (disclaimer: is somehow a "toy" script):
@Grapes([
@Grab(group='org.ccil.cowan.tagsoup', module='tagsoup', version='1.2.1')
])
def slurper = new XmlSlurper(new org.ccil.cowan.tagsoup.Parser())
def url = new URL("http://www.java.com/download/manual.jsp")
def html
url.withReader { reader ->
html = slurper.parse(reader)
}
def lastJava = html.body.div.div.div.strong.text()
println "Last available java version: ${lastJava}"
println "Currently installed java version: ${System.properties["java.version"]}"
It yields something like:
Last available java version:
Version 7 Update 9
Currently installed java version: 1.7.0_07
If you want to avoid maintenance issues due to changes to the page structure, maybe a better option is to search for a line containing "Version x Update y".
Comments
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,円
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 = ,円
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
Comments
(削除) @MarcelStör's solution no longer works - the version in the file is 1.8.0_51, while the actual latest version is 1.8.0_91/92. (削除ここまで) If you go to the Java test page in Firefox or Chrome and open the development console you can get the variable latest8Version which currently is 1.8.0_91. This could be wrapped in a Selenium/Firefox solution, but is an incredibly hacky way of getting this information.
1 Comment
curl -s http://java.com/en/download/installed8.jsp | grep latest8VersionSystem.getProperty("java.vm.specification.version");
System.getProperty("java.version");