Is there a way to include all the jar files within a directory in the classpath?
I'm trying java -classpath lib/*.jar:. my.package.Program and it is not able to find class files that are certainly in those jars. Do I need to add each jar file to the classpath separately?
Using Java 6 or later, the classpath option supports wildcards. Note the following:
Use straight quotes (")
Use *, not *.jar
Windows
java -cp "Test.jar;lib/*" my.package.MainClass
Unix
java -cp "Test.jar:lib/*" my.package.MainClass
This is similar to Windows, but uses : instead of ;. If you cannot use wildcards, bash allows the following syntax (where lib is the directory containing all the Java archive files):
java -cp "$(printf %s: lib/*.jar)"
(Note that using a classpath is incompatible with the -jar option. See also: Execute jar file with multiple classpath libraries from command prompt)
Understanding Wildcards
From the Classpath document:
Class path entries can contain the basename wildcard character *, which is considered equivalent to specifying a list of all the files
in the directory with the extension .jar or .JAR. For example, the
class path entry foo/* specifies all JAR files in the directory named
foo. A classpath entry consisting simply of * expands to a list of all
the jar files in the current directory.
A class path entry that contains * will not match class files. To
match both classes and JAR files in a single directory foo, use either
foo;foo/* or foo/*;foo. The order chosen determines whether the
classes and resources in foo are loaded before JAR files in foo, or
vice versa.
Subdirectories are not searched recursively. For example, foo/* looks
for JAR files only in foo, not in foo/bar, foo/baz, etc.
The order in which the JAR files in a directory are enumerated in the
expanded class path is not specified and may vary from platform to
platform and even from moment to moment on the same machine. A
well-constructed application should not depend upon any particular
order. If a specific order is required then the JAR files can be
enumerated explicitly in the class path.
Expansion of wildcards is done early, prior to the invocation of a
program's main method, rather than late, during the class-loading
process itself. Each element of the input class path containing a
wildcard is replaced by the (possibly empty) sequence of elements
generated by enumerating the JAR files in the named directory. For
example, if the directory foo contains a.jar, b.jar, and c.jar, then
the class path foo/* is expanded into foo/a.jar;foo/b.jar;foo/c.jar,
and that string would be the value of the system property
java.class.path.
The CLASSPATH environment variable is not treated any differently from
the -classpath (or -cp) command-line option. That is, wildcards are
honored in all these cases. However, class path wildcards are not
honored in the Class-Path jar-manifest header.
Note: due to a known bug in java 8, the windows examples must use a backslash preceding entries with a trailing asterisk: https://bugs.openjdk.java.net/browse/JDK-8131329
Under Windows this works:
java -cp "Test.jar;lib/*" my.package.MainClass
and this does not work:
java -cp "Test.jar;lib/*.jar" my.package.MainClass
Notice the *.jar, so the * wildcard should be used alone.
On Linux, the following works:
java -cp "Test.jar:lib/*" my.package.MainClass
The separators are colons instead of semicolons.
We get around this problem by deploying a main jar file myapp.jar which contains a manifest (Manifest.mf) file specifying a classpath with the other required jars, which are then deployed alongside it. In this case, you only need to declare java -jar myapp.jar when running the code.
So if you deploy the main jar into some directory, and then put the dependent jars into a lib folder beneath that, the manifest looks like:
Manifest-Version: 1.0
Implementation-Title: myapp
Implementation-Version: 1.0.1
Class-Path: lib/dep1.jar lib/dep2.jar
NB: this is platform-independent - we can use the same jars to launch on a UNIX server or on a Windows PC.
My solution on Ubuntu 10.04 using java-sun 1.6.0_24 having all jars in "lib" directory:
java -cp .:lib/* my.main.Class
If this fails, the following command should work (prints out all *.jars in lib directory to the classpath param)
java -cp $(for i in lib/*.jar ; do echo -n $i: ; done). my.main.Class
Short answer: java -classpath lib/*:. my.package.Program
Oracle provides documentation on using wildcards in classpaths here for Java 6 and here for Java 7, under the section heading Understanding class path wildcards. (As I write this, the two pages contain the same information.) Here's a summary of the highlights:
In general, to include all of the JARs in a given directory, you can use the wildcard * (not *.jar).
The wildcard only matches JARs, not class files; to get all classes in a directory, just end the classpath entry at the directory name.
The above two options can be combined to include all JAR and class files in a directory, and the usual classpath precedence rules apply. E.g. -cp /classes;/jars/*
The wildcard will not search for JARs in subdirectories.
The above bullet points are true if you use the CLASSPATH system property or the -cp or -classpath command line flags. However, if you use the Class-Path JAR manifest header (as you might do with an ant build file), wildcards will not be honored.
Yes, my first link is the same one provided in the top-scoring answer (which I have no hope of overtaking), but that answer doesn't provide much explanation beyond the link. Since that sort of behavior is discouraged on Stack Overflow these days, I thought I'd expand on it.
Windows:
java -cp file.jar;dir/* my.app.ClassName
Linux:
java -cp file.jar:dir/* my.app.ClassName
Remind:
- Windows path separator is ;
- Linux path separator is :
- In Windows if cp argument does not contains white space, the "quotes" is optional
For me this works in windows .
java -cp "/lib/*;" sample
For linux
java -cp "/lib/*:" sample
I am using Java 6
You can try java -Djava.ext.dirs=jarDirectory
http://docs.oracle.com/javase/6/docs/technotes/guides/extensions/spec.html
Directory for external jars when running java
Correct:
java -classpath "lib/*:." my.package.Program
Incorrect:
java -classpath "lib/a*.jar:." my.package.Program
java -classpath "lib/a*:." my.package.Program
java -classpath "lib/*.jar:." my.package.Program
java -classpath lib/*:. my.package.Program
If you are using Java 6, then you can use wildcards in the classpath.
Now it is possible to use wildcards in classpath definition:
javac -cp libs/* -verbose -encoding UTF-8 src/mypackage/*.java -d build/classes
Ref: http://www.rekk.de/bloggy/2008/add-all-jars-in-a-directory-to-classpath-with-java-se-6-using-wildcards/
If you really need to specify all the .jar files dynamically you could use shell scripts, or Apache Ant. There's a commons project called Commons Launcher which basically lets you specify your startup script as an ant build file (if you see what I mean).
Then, you can specify something like:
<path id="base.class.path">
<pathelement path="${resources.dir}"/>
<fileset dir="${extensions.dir}" includes="*.jar" />
<fileset dir="${lib.dir}" includes="*.jar"/>
</path>
In your launch build file, which will launch your application with the correct classpath.
Please note that wildcard expansion is broken for Java 7 on Windows.
Check out this StackOverflow issue for more information.
The workaround is to put a semicolon right after the wildcard. java -cp "somewhere/*;"
To whom it may concern,
I found this strange behaviour on Windows under an MSYS/MinGW shell.
Works:
$ javac -cp '.;c:\Programs\COMSOL44\plugins\*' Reclaim.java
Doesn't work:
$ javac -cp 'c:\Programs\COMSOL44\plugins\*' Reclaim.java
javac: invalid flag: c:\Programs\COMSOL44\plugins\com.comsol.aco_1.0.0.jar
Usage: javac <options> <source files>
use -help for a list of possible options
I am quite sure that the wildcard is not expanded by the shell, because e.g.
$ echo './*'
./*
(Tried it with another program too, rather than the built-in echo, with the same result.)
I believe that it's javac which is trying to expand it, and it behaves differently whether there is a semicolon in the argument or not. First, it may be trying to expand all arguments that look like paths. And only then it would parse them, with -cp taking only the following token. (Note that com.comsol.aco_1.0.0.jar is the second JAR in that directory.) That's all a guess.
This is
$ javac -version
javac 1.7.0
All the above solutions work great if you develop and run the Java application outside any IDE like Eclipse or Netbeans.
If you are on Windows 7 and used Eclipse IDE for Development in Java, you might run into issues if using Command Prompt to run the class files built inside Eclipse.
E.g. Your source code in Eclipse is having the following package hierarchy:
edu.sjsu.myapp.Main.java
You have json.jar as an external dependency for the Main.java
When you try running Main.java from within Eclipse, it will run without any issues.
But when you try running this using Command Prompt after compiling Main.java in Eclipse, it will shoot some weird errors saying "ClassNotDef Error blah blah".
I assume you are in the working directory of your source code !!
Use the following syntax to run it from command prompt:
javac -cp ".;json.jar" Main.java
java -cp ".;json.jar" edu.sjsu.myapp.Main
[Don't miss the . above]
This is because you have placed the Main.java inside the package edu.sjsu.myapp and java.exe will look for the exact pattern.
Hope it helps !!
macOS, current folder
For Java 13 on macOS Mojave…
If all your .jar files are in the same folder, use cd to make that your current working directory. Verify with pwd.
For the -classpath you must first list the JAR file for your app. Using a colon character : as a delimiter, append an asterisk * to get all other JAR files within the same folder. Lastly, pass the full package name of the class with your main method.
For example, for an app in a JAR file named my_app.jar with a main method in a class named App in a package named com.example, alongside some needed jars in the same folder:
java -classpath my_app.jar:* com.example.App
For windows quotes are required and ; should be used as separator. e.g.:
java -cp "target\\*;target\\dependency\\*" my.package.Main
Short Form: If your main is within a jar, you'll probably need an additional '-jar pathTo/yourJar/YourJarsName.jar ' explicitly declared to get it working (even though 'YourJarsName.jar' was on the classpath)
(or, expressed to answer the original question that was asked 5 years ago: you don't need to redeclare each jar explicitly, but does seem, even with java6 you need to redeclare your own jar ...)
Long Form:
(I've made this explicit to the point that I hope even interlopers to java can make use of this)
Like many here I'm using eclipse to export jars: (File->Export-->'Runnable JAR File'). There are three options on 'Library handling' eclipse (Juno) offers:
opt1: "Extract required libraries into generated JAR"
opt2: "Package required libraries into generated JAR"
opt3: "Copy required libraries into a sub-folder next to the generated JAR"
Typically I'd use opt2 (and opt1 was definitely breaking), however native code in one of the jars I'm using I discovered breaks with the handy "jarinjar" trick that eclipse leverages when you choose that option. Even after realizing I needed opt3, and then finding this StackOverflow entry, it still took me some time to figure it out how to launch my main outside of eclipse, so here's what worked for me, as it's useful for others...
If you named your jar: "fooBarTheJarFile.jar"
and all is set to export to the dir: "/theFully/qualifiedPath/toYourChosenDir".
(meaning the 'Export destination' field will read: '/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile.jar' )
After you hit finish, you'll find eclipse then puts all the libraries into a folder named 'fooBarTheJarFile_lib' within that export directory, giving you something like:
/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile.jar
/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile_lib/SomeOtherJar01.jar
/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile_lib/SomeOtherJar02.jar
/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile_lib/SomeOtherJar03.jar
/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile_lib/SomeOtherJar04.jar
You can then launch from anywhere on your system with:
java -classpath "/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile_lib/*" -jar /theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile.jar package.path_to.the_class_with.your_main.TheClassWithYourMain
(For Java Newbies: 'package.path_to.the_class_with.your_main' is the declared package-path that you'll find at the top of the 'TheClassWithYourMain.java' file that contains the 'main(String[] args){...}' that you wish to run from outside java)
The pitfall to notice: is that having 'fooBarTheJarFile.jar' within the list of jars on your declared classpath is not enough. You need to explicitly declare '-jar', and redeclare the location of that jar.
e.g. this breaks:
java -classpath "/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile.jar;/theFully/qualifiedPath/toYourChosenDir/fooBarTheJarFile_lib/*" somepackages.inside.yourJar.leadingToTheMain.TheClassWithYourMain
restated with relative paths:
cd /theFully/qualifiedPath/toYourChosenDir/;
BREAKS: java -cp "fooBarTheJarFile_lib/*" package.path_to.the_class_with.your_main.TheClassWithYourMain
BREAKS: java -cp ".;fooBarTheJarFile_lib/*" package.path_to.the_class_with.your_main.TheClassWithYourMain
BREAKS: java -cp ".;fooBarTheJarFile_lib/*" -jar package.path_to.the_class_with.your_main.TheClassWithYourMain
WORKS: java -cp ".;fooBarTheJarFile_lib/*" -jar fooBarTheJarFile.jar package.path_to.the_class_with.your_main.TheClassWithYourMain
(using java version "1.6.0_27"; via OpenJDK 64-Bit Server VM on ubuntu 12.04)
You need to add them all separately. Alternatively, if you really need to just specify a directory, you can unjar everything into one dir and add that to your classpath. I don't recommend this approach however as you risk bizarre problems in classpath versioning and unmanagability.
The only way I know how is to do it individually, for example:
setenv CLASSPATH /User/username/newfolder/jarfile.jar:jarfile2.jar:jarfile3.jar:.
Hope that helps!
class from wepapp:
> mvn clean install
> java -cp "webapp/target/webapp-1.17.0-SNAPSHOT/WEB-INF/lib/tool-jar-1.17.0-SNAPSHOT.jar;webapp/target/webapp-1.17.0-SNAPSHOT/WEB-INF/lib/*" com.xx.xx.util.EncryptorUtils param1 param2
Think of a jar file as the root of a directory structure. Yes, you need to add them all separately.
Not a direct solution to being able to set /* to -cp but I hope you could use the following script to ease the situation a bit for dynamic class-paths and lib directories.
libDir2Scan4jars="../test";cp=""; for j in `ls ${libDir2Scan4jars}/*.jar`; do if [ "$j" != "" ]; then cp=$cp:$j; fi; done; echo $cp| cut -c2-${#cp} > .tmpCP.tmp; export tmpCLASSPATH=`cat .tmpCP.tmp`; if [ "$tmpCLASSPATH" != "" ]; then echo .; echo "classpath set, you can now use ~> java -cp \$tmpCLASSPATH"; echo .; else echo .; echo "Error please check libDir2Scan4jars path"; echo .; fi;
Scripted for Linux, could have a similar one for windows too. If proper directory is provided as input to the "libDir2Scan4jars"; the script will scan all the jars and create a classpath string and export it to a env variable "tmpCLASSPATH".
Set the classpath in a way suitable multiple jars and current directory's class files.
CLASSPATH=${ORACLE_HOME}/jdbc/lib/ojdbc6.jar:${ORACLE_HOME}/jdbc/lib/ojdbc14.jar:${ORACLE_HOME}/jdbc/lib/nls_charset12.jar;
CLASSPATH=$CLASSPATH:/export/home/gs806e/tops/jconn2.jar:.;
export CLASSPATH
I have multiple jars in a folder. The below command worked for me in JDK1.8 to include all jars present in the folder. Please note that to include in quotes if you have a space in the classpath
Windows
Compiling: javac -classpath "C:\My Jars\sdk\lib\*" c:\programs\MyProgram.java
Running: java -classpath "C:\My Jars\sdk\lib\*;c:\programs" MyProgram
Linux
Compiling: javac -classpath "/home/guestuser/My Jars/sdk/lib/*" MyProgram.java
Running: java -classpath "/home/guestuser/My Jars/sdk/lib/*:/home/guestuser/programs" MyProgram
Order of arguments to java command is also important:
c:\projects\CloudMirror>java Javaside -cp "jna-5.6.0.jar;.\"
Error: Unable to initialize main class Javaside
Caused by: java.lang.NoClassDefFoundError: com/sun/jna/Callback
versus
c:\projects\CloudMirror>java -cp "jna-5.6.0.jar;.\" Javaside
Exception in thread "main" java.lang.UnsatisfiedLinkError: Unable
java -server -Xmx2G -cp config:./* l2p.loginserver.LoginServer
MAC: OK!
WINDOWS: Cannot find class l2p.loginserver.LoginServer
LINUX: Cannot find class l2p.loginserver.LoginServer
Aditional info: jar file is called kernel.jar and it's in the same folder where the command is executed
if i use java -server -cp kernel.jar l2p.loginserver.LoginServer the class is started to load but i need config because i have log4j xml there.
Thanks!
See this answer
In java classpath, if you use wildcard *, it only loads the .jar files from that location.
java -server -Xmx2G -cp config:kernel.jar l2p.loginserver.LoginServer
Problem with log4j is that the first log4j.xml in the classpath will be loaded. So put the config in front.
I don't think you can use globbing like that in a -cp argument. They won't be expanded in the right way, colon-separated as you need them. Try
java -cp config:kernel.jar l2p.loginserver.LoginServer
(With the other arguments you need, of course.)
Note that this is assuming you're on Unix. On Windows you'd need
java -cp config;kernel.jar l2p.loginserver.LoginServer
(The path separator is ; on Windows, but : on Unix.)
I have a folder on my desktop titled "Stuff" and in that folder I have the following:
Hello.java
mail.jar
And Hello.java imports from mail.jar, so I need to tell Hello.java to look for mail.jar.
From a Windows command line and from a unix command line, how can I compile this and run this?
Compile:
javac -cp .;mail.jar Hello.java
where ; is for Windows; use : for *nix.
and run:
java -cp .;mail.jar Hello
where again, use ; for Windows and : for *nix.
-cp tells both javac and java what classpath to use, and as your files are in the local directory where you're executing the command, you can use . for the Hello part and the name of the jar for the paths inside the jar. Wikipedia has a decent article on classpaths.
Mind you, if you're going to be doing this on a regular basis, you may want to set your CLASSPATH environment variable rather than constantly using the -cp flag. Both java and javac use the CLASSPATH variable.
For my own development machine, I actually include . in my CLASSPATH variable, for convenience. It's not something I would do on a production or build/test box, but it's very handy for development purposes. You'd want to have your usual jars in it as well.
Assuming Hello.java does not contain a package declaration, on Windows:
javac -cp mail.jar Hello.java
java -cp mail.jar;. Hello
The only difference on Unix platforms is that you separate the elements of the classpath with a scolon instead of a semicolon:
java -cp mail.jar:. Hello
Follow this tutorial and you should be able to do it in no time:
Java Compilation
You also shouldn't have any problems with the classpath because your classes are in the same folder
CLASSPATH has the "/Users/smcho/Desktop/clojure" as one of its path, and this directory has the file hello.clj.
Running clojure, and running (require 'hello) give this error message.
java.io.FileNotFoundException: Could not locate hello__init.class or hello.clj on classpath: (NO_SOURCE_FILE:0)
When I change directory to "/Users/.../clojure", and run the same (require 'hello), there's no problem. The . is on the CLASSPATH.
Running
java -cp /Users/smcho/bin/jar/clojure.jar:/Users/smcho/Desktop/clojure clojure.lang.Repl
also works.
Why clojure can't find the source on the CLASSPATH?
Like Alex mentioned, if you start java with the -cp argument, then the CLASSPATH environment is not referenced. So, instead of
java -cp /Users/smcho/bin/jar/clojure.jar clojure.lang.Repl
use
java -cp /Users/smcho/bin/jar/clojure.jar:$CLASSPATH clojure.lang.Repl
You can examine your java classpath from within the Clojure repl:
(doseq [p (.getURLs (java.lang.ClassLoader/getSystemClassLoader))] (println (.getPath p)))
You didn't specify what commandline you used for the first example, but note that if you use the -cp flag, the CLASSPATH environment variable is not referenced.
I have a .jar file that I would like to be able to call without having to use a full file path to its location.
For example, if the .jar file is located at: /some/path/to/thearchive.jar
I'd like to be able to run it with:
java -jar thearchive.jar
instead of:
java -jar /some/path/to/thearchive.jar
when I'm elsewhere in the directory tree. In my specific case, I'm running a Mac with OS X 10.5.7 installed. Java version "1.5.0_16". I tried adding "/some/path/to" to PATH, JAVA_HOME and CLASSPATH, but that didn't work.
So, how do I setup to run a .jar from the command line without having to use its full path?
UPDATE: Another item to deal with would be arguments. For example:
java -jar /some/path/to/thearchive.jar arg1 arg2
This can have an effect on the way the question is dealt with as mentioned in the answers below.
You can add a variable to hold the directory:
export JARDIR=/some/path/to
java -jar $JARDIR/thearchive.jar
I'm not sure you can do it from environment variables implicitly.
No you can't.
Running a jar with -jar does not involve any kind of classpath mechanism since the jar file is the classpath.
Alternatively use a shell alias to launch the jar or a small script file.
According to Sun:
java -jar app.jar
To run the application from jar file that is in other directory, we need to specify the path of that directory as below: java -jar path/app.jar
where path is the directory path at which this app.jar resides.
So either out the path in a "standard" environment variable or define a wrapper which would be in your PATH
I don't believe so. If you have the jar specified in your CLASSPATH you could just call java with the main class specified. (i.e java com.test.Main) Alternatively you could create an alias in you shell to execute the command
alias execJar="java -jar /some/path/to/thearchive.jar"
Or another alternative is to create a wrapper script to execute it.
The Java system itself does not give you a way to specify something like JAR_PATH (a list of places to look for jar files). The other answers given use the MAC/Unix shell capabilities:
Setting an environment variable
Setting an alias
Possibly using a symbolic link (to the file or to the directory).
What might be helpful is to find out why specifying the entire path is a problem. That may guide us as to which answer is best or possibly find a completely different solution to your problem.
To run a .jar file without typing the full path you can put it in your classpath and run it by typing:
java fullclassname arg1 arg2
Mac OSX Developer Library recommends 'additional jar files that need to be placed on the system classpath be placed in the /Library/Java/Extensions folder. You can also put them in your own Library/Java/Extensions folder, but you will probably have to create the Java and Extensions folders.
If you do not know the full name of the main class in your .jar file, you can expand it and look in the MANIFEST.MF file in the META-INF folder. The Main-Class: line will tell you.
So, for example, to run the saxon9he.jar put it in /Library/Java/Extensions and you can type (from whichever folder you want)
java net.sf.saxon.Transform arg1 arg2...
Almost as short as typing java -jar jarfile.jar arg1 arg2, and you don't need to change any environment variables.
In short, if the jar is in your classpath, use the classname and you don't need the pathname.
Since there is no extra command line option for the location of jars or an environment variable is taken into account I am also not aware of an easy solution but would be highly interested in it as well.
A different approach could be to use a zsh wrapper script to get such a behaviour:
~/.scripts/java # .scripts at a prior position in your $PATH variable than java itself
#!/usr/bin/env zsh
# get -jar option and remove from $# (-D option)
zparseopts -D jar:=jarname
if [ -e $JAR_PATH/$jarname[2] ];
then
java -jar $JAR_PATH/$jarname[2] $#
elif [ -e $jarname[2] ];
then
java -jar $jarname[2] $#
else
java $#
fi
An advantage of zparseopts is that it can strip off the -jar option but all other options are retained within $#.
A further improvement would be to extend bash-completion or zsh-completion for the java command option -jar. For instance bash-completion of java -jar restricts file listings to *.jar files. For convenient usage someone could extend this by not only looking into current path but into $JAR_PATH. As a starting point see following unix.sx question.
But this solution doesn't look too good either.