how to check the version of jar file

Question

I am currently working on a J2ME polish application  just enhancing it  I am finding difficulties to get the exact version of the jar file  Is there any way to find the version of the jar file for the imports done in the class  I mean if you have some thing  import x y z  can we know the version of the jar x y package belongs to

User · Accepted Answer

Decompress the JAR file and look for the manifest file  META-INF MANIFEST MF   The manifest file of JAR file might contain a version number  but not always a version is specified

User · Answer

Thought I would give a more recent answer as this question still comes up pretty high on searches   Checking CLi JAR Version   Run the following on the CLi jar file   unzip -p jenkins-cli jar META-INF MANIFEST MF   Example Output   Manifest-Version  1 0 Built-By  kohsuke Jenkins-CLI-Version  2 210   lt --- Jenkins CLI Version Created-By  Apache Maven 3 6 1 Build-Jdk  1 8 0 144 Main-Class  hudson cli CLI   The CLi version is listed above   To get the Server Version  run the following   java -jar   jenkins-cli jar -s https    lt Server URL gt  -auth  lt email gt   lt domain gt  com  lt API Token gt  version    the above will vary based on your implementation of authentication  please change accordingly   Example Output   Dec 23  2019 4 42 55 PM org apache sshd common util security AbstractSecurityProviderRegistrar getOrCreateProvider INFO  getOrCreateProvider EdDSA  created instance of net i2p crypto eddsa EdDSASecurityProvider 2 210   lt -- Jenkins Server Version

User · Answer

For Linux  try following   find   -name  YOUR JAR FILE jar  -exec zipgrep  Implementation-Version           awk -F        print  2

User · Answer

Just to expand on the answers above  inside the META-INF MANIFEST MF file in the JAR  you will likely see a line  Manifest-Version  1 0    This is NOT the jar versions number   You need to look for Implementation-Version which  if present  is a free-text string so entirely up to the JAR s author as to what you ll find in there  See also Oracle docs and Package Version specificaion

User · Answer

You need to unzip it and check its META-INF MANIFEST MF file  e g   unzip -p file jar   head   or more specific   unzip -p file jar META-INF MANIFEST MF

User · Answer

Each jar version has a unique checksum  You can calculate the checksum for you jar  that had no version info  and compare it with the different versions of the jar  We can also search a jar using checksum   Refer this Question to calculate checksum  What is the best way to calculate a checksum for a file that is on my machine

User · Answer

It can be checked with a command java -jar jarname

User · Answer

Basically you should use the java lang Package class which use the classloader to give you informations about your classes   example   String class getPackage   getImplementationVersion    Package getPackage this  getImplementationVersion    Package getPackage  java lang String   getImplementationVersion      I think logback is known to use this feature to trace the JAR name version of each class in its produced stacktraces   see also http   docs oracle com javase 8 docs technotes guides versioning spec versioning2 html wp90779

User · Answer

This simple program will list all the cases for version of jar namely   Version found in Manifest file No version found in Manifest and even from jar name Manifest file not found  Map lt String  String gt  jarsWithVersionFound     new LinkedHashMap lt String  String gt     List lt String gt  jarsWithNoManifest       new LinkedList lt String gt     List lt String gt  jarsWithNoVersionFound   new LinkedList lt String gt        loop through the files in lib folder   pick a jar one by one and getVersion     print in console  save to file     maybe later  File   files   new File  path to jar folder   listFiles     for File file   files        String fileName   file getName          try               String jarVersion   new Jar file  getVersion             if jarVersion    null              jarsWithNoVersionFound add fileName           else             jarsWithVersionFound put fileName  jarVersion              catch Exception ex                jarsWithNoManifest add fileName            System out println          JARs with versions found            for Entry lt String  String gt  jarName   jarsWithVersionFound entrySet        System out println jarName getKey             jarName getValue      System out println   n  n         JARs with no versions found            for String jarName   jarsWithNoVersionFound      System out println jarName    System out println   n  n         JARs with no manifest found            for String jarName   jarsWithNoManifest      System out println jarName      It uses the javaxt-core jar which can be downloaded from http   www javaxt com downloads

User · Answer

I m late this but you can try the following two methods  using these needed classes  import java util jar Attributes  import java util jar Manifest    These methods let me access the jar attributes  I like being backwards compatible and use the latest  So I used this  public Attributes detectClassBuildInfoAttributes Class sourceClass  throws MalformedURLException  IOException       String className   sourceClass getSimpleName       class       String classPath   sourceClass getResource className  toString        if   classPath startsWith  jar               Class not from JAR       return null            String manifestPath   classPath substring 0  classPath lastIndexOf        1               META-INF MANIFEST MF       Manifest manifest   new Manifest new URL manifestPath  openStream         return manifest getEntries   get  Build-Info       public String retrieveClassInfoAttribute Class sourceClass  String attributeName  throws MalformedURLException  IOException       Attributes version attr   detectClassBuildInfoAttributes sourceClass        String attribute   version attr getValue attributeName        return attribute      This works well when you are using maven and need pom details for known classes  Hope this helps

User · Answer

If you have winrar  open the jar with winrar  double-click to open folder META-INF  Extract MANIFEST MF and CHANGES files to any location  say desktop     Open the extracted files in a text editor  You will see Implementation-Version or release version

User · Answer

You can filter version from the MANIFEST file using   unzip -p my jar META-INF MANIFEST MF   grep  Bundle-Version

User · Answer

Just to complete the above answer   Manifest file is located inside jar at META-INF MANIFEST MF path   You can examine jar s contents in any archiver that supports zip

[jar] how to check the version of jar file?

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