I've been learning java on my own and I've come to a point where I need to pass arguments from the command prompt. I had previously been using Netbeans, which has become a bit of a crutch, but I want to learn how to program using notepad and the command prompt. I am running Windows 8.1. I downloaded the JDK 7 to my C:\ directory. I tried typing "java -version" and "javac -version" to check it out (as my book says to do) but it tells me "'java' is not recognized as an internal or external command, operable program or batch file." It says the same when I try javac. I do this from C:\ and from C:\Java> and get the same result. I uninstalled Netbeans, thinking maybe it was interfering somehow ... still not working. The book I'm using says it covers Java 7.
I don't understand why it doesn't work. Is there some compatibility issue with Java 7 and win 8.1? My java 7 is update 71 or 72. Did this update change something and now arguments are passed differently? Can anyone help me out? Thank you.
You need to download the JDK (if you don't already have it) and add the location to the end of your PATH. In a single command line session you can do this with PATH=%PATH%;<jdk location> where <jdk location> is the bin folder of the jdk.
Some installs of java manage environment variables and some do not. It appears yours has not. or you have not installed it correctly.
many applications understand JAVA_HOME, so you should set that to the root of the installation in your environment variables.
You will also need to add the bin folder to your path.
Generally, when using windows, you can install a windows exe version, which will manage all of this for you. Other installations just copy themselves to the c drive and expect java applications to know where to look.
Go to System environment variable. Select Variable PATH. Click on edit button. Append a ; after current value of Variable value. Copy jdk's bin folder path. In my PC it is "C:\Program Files\Java\jdk1.8.0_20\bin" without quotes. Then paste jdk's bin path. Copy jre's bin folder path. In my PC it is "C:\Program Files\Java\jdk1.8.0_20\jre\bin". Append a ; then paste jre's bin folder path. Click OK.
Download the JDK from this page. Run the installer.
Open the Command Prompt. Try it. It works. Yay!
If you use the full path to your java.exe, you dont need to set up any PATH and JAVA_HOME:
c:\> cd \work
c:\work> c:\java\bin\java.exe -cp classes\ your.Main
If your book does not use the normal JDK installers it really is supposed to explain that. (However it is normal behaviour for any executable).
(The above example asumes you compile into c:\work\classes\your\Main.class and your JDK is installed (installer does the unpack) in C:\java (typically you would use default locations like C:\Program Files\Java\jdk1.8.0\bin\java.exe).
I have CQ5 executable jar file.It is suppose to be executed on double clicking.But i get error saying "could not find Main class program will exit".The same jar file executed on all my team mates machine but i am unable to execute it.
I am working on windows 7 OS.
I have jre6 installed.
I have done all steps provided in following link .jar file keeps giving me " could not find the main class". Program will exit.
my ftype and assoc is set to propervalue.
there is no problem in manifest file(becoz it executed on others machine).
all my path variables are set properly.
type of file on my system is "JAR" but on everyone else machine its "Executable JAR"
Could not figure out what is problem with my system.
Help plz.
You can alternatively try executing this command from a command console,
first CD to the location where you have the jar file and execute
For Win7 32-bit:
java -Xmx1024M -jar .jar
For Win7 64-bit:
java -XX:MaxPermSize=256m -Xmx1024M -jar .jar
if you have supported version of Java installed correctly, then the command should be able to start the CQ5 server. In that case, for fixing the double click issue, you would need to fix the filetype association of .jar files to open with /bin/javaw.exe
For supported Java versions, refer
CQ5.5 http://dev.day.com/docs/en/cq/5-5/deploying/technical_requirements.html
CQ5.6 http://dev.day.com/docs/en/cq/5-6/deploying/technical_requirements.html
I want to execute my program without using an IDE.
I've created a jar file and an exectuable jar file. When
I double click the exe jar file, nothing happens, and when I try to use the command in cmd it gives me this:
Error: Unable to access jarfile <path>
I use the command: java -jar Calculator.jar
How I created the jar:
Right click on project folder (Calculator)
Select
Click on Java Folder and select "Exectuable Jar File", then select next
Launch Configuration: Main - Calculator
Create Export Destination
Hit "Finish" and profit! Well, not really.
I had encountered this issue when I had run my Jar file as
java -jar TestJar
instead of
java -jar TestJar.jar
Missing the extension .jar also causes this issue.
Fixed
I just placed it in a different folder and it worked.
[Possibly Windows only]
Beware of spaces in the path, even when your jar is in the current working directory. For example, for me this was failing:
java -jar myjar.jar
I was able to fix this by givng the full, quoted path to the jar:
java -jar "%~dp0\myjar.jar"
Credit goes to this answer for setting me on the right path....
I had this issue under CygWin in Windows. I have read elsewhere that Java does not understand the CygWin paths (/cygdrive/c/some/dir instead of C:\some\dir) - so I used a relative path instead: ../../some/dir/sbt-launch.jar.
I had the same issue when trying to launch the jar file. The path contained a space, so I had to place quotes around. Instead of:
java -jar C:\Path to File\myJar.jar
i had to write
java -jar "C:\Path to File\myJar.jar"
Just came across the same problem trying to make a bad USB...
I tried to run this command in admin cmd
java -jar c:\fw\ducky\duckencode.jar -I c:\fw\ducky\HelloWorld.txt -o c:\fw\ducky\inject.bin
But got this error:
Error: unable to access jarfile c:\fw\ducky\duckencode.jar
Solution
1st step
Right click the jarfile in question. Click properties.
Click the unblock tab in bottom right corner.
The file was blocked, because it was downloaded and not created on my PC.
2nd step
In the cmd I changed the directory to where the jar file is located.
cd C:\fw\ducky\
Then I typed dir and saw the file was named duckencode.jar.jar
So in cmd I changed the original command to reference the file with .jar.jar
java -jar c:\fw\ducky\duckencode.jar.jar -I c:\fw\ducky\HelloWorld.txt -o c:\fw\ducky\inject.bin
That command executed without error messages and the inject.bin I was trying to create was now located in the directory.
Hope this helps.
None of the provided answers worked for me on macOS 11 Big Sur. The problem turned out to be that programs require special permission to access the Desktop, Documents, and Downloads folders, and Java breaks both the exception for directly opened files and the permission request popup.
Fixes:
Move the .jar into a folder that isn’t (and isn’t under) Documents, Desktop, or Downloads.
Manually grant the permission. Go to System Preferences → Security and Privacy → Privacy → Files and Folders → java, and check the appropriate folders.
I had a similar problem and I even tried running my CMD with administrator rights, but it did not solve the problem.
The basic thing is to make sure to change the Directory in cmd to the current directory where your jar file is.
Do the following steps:
Copy jar file to Desktop.
Run CMD
Type command cd desktop
Then type java -jar filename.jar
This should work.
Edit: From JDK-11 onwards ( JEP 330: Launch Single-File Source-Code Programs )
Since Java 11, java command line tool has been able to run a single-file source-code directly. e.g.
java filename.java
If you are using OSX, downloaded files are tagged with a security flag that prevents unsigned applications from running.
to check this you can view extended attributes on the file
$ ls -l#
-rw-r--r--# 1 dave staff 17663235 13 Oct 11:08 server-0.28.2-java8.jar
com.apple.metadata:kMDItemWhereFroms 619
com.apple.quarantine 68
You can then clear the attributes with
xattr -c file.jar
It can also happen if you don't properly supply your list of parameters. Here's what I was doing:
java -jar test#gmail.com testing_subject file.txt test_send_emails.jar
Instead of the correct version:
java -jar test_send_emails.jar test#gmail.com testing_subject file.txt
This worked for me.
cd /path/to/the/jar/
java -jar ./Calculator.jar
For me it happens if you use native Polish chars in foldername that is in the PATH.
So maybe using untypical chars was the reason of the problem.
sometime it happens when you try to (run or create) a .jar file under /libs folder by right click it in android studio. you can select the dropdown in top of android stuio and change it to app. This will work
My particular issue was caused because I was working with directories that involved symbolic links (shortcuts). Consequently, trying java -jar ../../myJar.jar didn't work because I wasn't where I thought I was.
Disregarding relative file paths fixed it right up.
In my case the suggested file name to be used was jarFile*.jar in the command line. The file in the folder was jarFile-1.2.3.jar . So I renamed the file to jarFile. Then I used jarFile.jar instead of jarFile*.jar and then the problem got resolved
It can happen on a windows machine when you have spaces in the names of the folder. The solution would be to enter the path between " ".
For example:
java -jar c:\my folder\x.jar -->
java -jar "c:\my folder\x.jar"
To avoid any permission issues, try to run it as administrator. This worked for me on Win10.
I know this thread is years ago and issue was fixed too. But I hope this would helps someone else in future since I've encountered some similar issues while I tried to install Oracle WebLogic 12c and Oracle OFR in which its installer is in .jar format. For mine case, it was either didn't wrap the JDK directory in quotes or simply typo.
Run Command Prompt as administrator and execute the command in this format. Double check the sentence if there is typo.
"C:\Program Files\Java\jdk1.xxxxx\bin\java" -jar C:\Users\xxx\Downloads\xxx.jar
If it shows something like JRE 1.xxx is not a valid JDK Java Home, make sure the System variables for JAVA_HOME in Environment Variables is pointing to the correct JDK directory. JDK 1.8 or above is recommended (2018).
A useful thread here, you may refer it: Why its showing your JDK c:program files\java\jre7 is not a valid JDK while instaling weblogic server?
For me it happen because i run it with default java version (7) and not with compiled java version (8) used to create this jar.
So i used:
%Java8_64%\bin\java -jar myjar.jar
Instead of java 7 version:
java -jar myjar.jar
I had a similar problem where TextMate or something replaced the double quotes with the unicode double quotes.
Changing my SELENIUM_SERVER_JAR from the unicode double quotes to regular double quotes and that solved my problem.
this is because you are looking for the file in the wrong path
1. look for the path of the folder where you placed the file
2. change the directory cd in cmd use the right path
I use NetBeans and had the same issue. After I ran build and clean project my program was executable. The Java documentation says that the build/clean command is for rebuilding the project from scratch basically and removing any past compiles. I hope this helps. Also, I'd read the documentation. Oracle has NetBeans and Java learning trails. Very helpful. Good luck!
Maybe you have specified the wrong version of your jar.
I finally pasted my jar file into the same folder as my JDK so I didn't have to include the paths. I also had to open the command prompt as an admin.
Right click Command Prompt and "Run as administrator"
Navigate to the directory where you saved your jdk to
In the command prompt type: java.exe -jar <jar file name>.jar
Keep the file in same directory where you are extracting it. That worked for me.
This is permission issue, see if the directory is under your User.
That's why is working in another folder!
Rename the jar file and try
Explanation :
yes, I know there are many answers still I want to add one point here which I faced.
I built the jar and I moved it into the server where I deploy (This is the normal process)
here the file name which I moved already existed in the server, here the file will override obviously right. In this case, I faced this issue.
maybe at the time of overriding there can be a permission copy issue.
Hope this will help someone.
Have you tried to run it under administrator privoleges?
meaning, running the command in "Run As" and then select administrator with proper admin credentials
worked for me
I was trying this:
After giving the file read, write, execute priviledges:
chmod 777 java-repl.jar
alias jr="java -jar $HOME/Dev/java-repl/java-repl.jar"
Unable to access bla bla..., this was on Mac OS though
So I tried this:
alias jr="cd $HOME/Dev/java-repl/ && java -jar java-repl.jar"
This did not work "Unable to access jarfile"
"C:\Program Files\java\jdk-13+33-jre\bin\javaw.exe" -jar "C:\Program Files\Maxim Integrated Products\1-Wire Drivers x64\ OneWireViewer.jar"
This does work
"C:\Program Files\java\jdk-13+33-jre\bin\javaw.exe" -jar "C:\Program Files\Maxim Integrated Products\1-Wire Drivers x64\OneWireViewer.jar"
The difference is the single space in front of OneWireViewer.jar not withstanding that it is surrounded with quotes and even has other spaces.
I just created a jar file using jdk7. I tried running it but kept getting an error. It turned out it was pointing at a jre6 and not the jre in jdk7. So, I used the following command to change it
ftype jarfile = "C:\path to jre\bin\javaw.exe" -jar "%1" %*
After that, I tried to double click on my jar file again, but it popped up a window asking me to choose a program to open it with. When I chose the same javaw.exe file as above it runs but exits immediately without doing anything. I can run it fine in cmd by doing the java -jar file.jar command. I even tried deleting the .jar registry key, but that just got me back to the point where it asked me to choose a program to open with. I'm running windows 7 ultimate if that matters.
EDIT:
In the registry there are 3 subkeys: OpenWithList, OpenWithProgids, and UserChoice. I've changed all the defaults to the path above except UserChoice which won't let me edit it from regedit. When I delete that and try to run the jar file, it opens up the choose a program to open with window again. For some reason it ignores the other registry keys
OK, I found the answer somewhere else but ran into this issue again so came here via google.
The solution is...
Open up regedit.exe
Either search for "jre6" or follow this: HKLM->SOFTWARE->Classes->jarfile->shell->open->command
Change the Data field to the directory of the javaw.exe file that's in your JDK directory.
For the love of God, don't forget to put the weird [-jar "%1" %*] parts on the end of it.
Enjoy outsmarting Oracle.
Hopefully this'll save some people a bit of time.
This happened to me when I installed the JRE6 plugin for Chrome, though it could happen when installing any other JRE I guess.
I fixed it by going to regedit and searched for jre which brought up...
HKEY_CURRENT_USER/Software/Classes/Applications/javaw.exe/shell/open/command
I changed the REG_SZ
from: "C:\Program Files (x86)\Java\jre7\bin\javaw.exe" "%1"
to: "C:\Program Files (x86)\Java\jre7\bin\javaw.exe" -jar "%1" %*
When windows asks you for a program to run it against it won't insert the needed -jar argument in the command line.
If it's asking you for the exe in which to run it then that means somehow your JRE isn't associated with the .jar extension. You'll need to modify the .jar file registry entry so that it runs c:\path_to_jre\bin\javaw -jar %1 in order for it to work.
It used to be under File Explorer > Tools > Folder Options > File Types.
Then look for .jar in there. You should find a text field that shows the executable to run and the command line arguments. That's what you want to modify. You can also do it in the registry editor too, but I've forgotten the HKEY variable path. I'm sure this KBA will help:
support_microsoft_kb_950505
Check if the file type jarfile is actually registered with the *.jar extension using
assoc .jar
Seems like .jar is not linked to jarfile.
I'm not sure exactly why none of the solutions worked, but I reinstalled jre7 and it works now.
Isn't it easier to change your java version to you rnew jdk7 by changing the CLASSPATH environment variable? See how here
I have written a Java GUI app (using Netbeans 6.7) requiring Java 1.6. I successfully run it on my XP PC and also my Mac OSX (10.5.7).
My client is running Vista Business, and cannot run the application by double clicking the jar file. He can execute it from the command line: "javaw -jar ..." The error received is: "Cannot find the main class... Program will exit".
I've asked the client to do the following:
install the latest JRE
run JarFix
I've verified that:
JRE is installed in correct location
jar file association is correct
application works (as I have tested it on XP and Mac OSX, and the client can run it from the command line)
Any ideas on what else I can investigate? Note, Netbeans created the main jar file, and also a lib directory with a couple of other Jarfiles. I've unzipped the jarfile and examined the manifest file (which looks good). The correct main class is also within the app's jarfile.
Does the client need to be careful as to where the application is executed from in Vista?
Thanks very much.
Prembo
Does exactly the same JAR file work on other operating systems?
Is the manifest file (META-INF/MANIFEST.MF) in the JAR file correct? One catch to watch out for is that the manifest file MUST end with an empty line; if it doesn't, the last line in the manifest file will be ignored. So, for example, if the last line in your manifest file is something like this:
Main-Class: com.mypackage.MyProgram
and it is not followed by an empty line, then Java will ignore the line and it will not be able to find the main class of the program.
See Sun's Java Tutorial about deploying Java programs in JAR files for exact details about how to package your application in a JAR; it also contains the warning about the manifest file needing to end with an empty line.
Also, double-check if the right version of Java is used. Are you using the exact same version of Java as on Windows XP? Try:
java -version
to see which Java version is being used.
I'm running Vista Enterprise and have very little differences between it and other Windows versions (with regards to Java).
Here are some random ideas that may or may not work:
Have you tried: right clicking on the Jar -> Open with -> Java(TM) Platform SE Binary
Could it be permissions related? (probably not since it runs via the command line)
Have you tried it with UAC off? (UAC sandboxes java apps, and they can't write to certain locations like Program Files)
Did you make sure they have the same files as you in JAVA_HOME/lib/ext/
you could try setting environment variables:
JAVA_HOME=<your_java_home>
CLASSPATH=.
PATH=<your_java_home>\bin
Sometimes JDK needs to be installed separately,along with the net beans IDE. If you have jdk installed then you can try checking for classpath,path in the environmental variables.