I am using MobaXterm, a friendly Unix terminal that runs on Windows. I want to compile a simple Java program using the javac command. After looking at plenty of other forums, I know I need to use the path where Java is installed, but no matter what I try, I keep getting the error
javac command not found
on the terminal. Can someone please help me out with compiling basic Java programs from within their directory on a Unix terminal on Windows?
And yes, I have JDK for Windows installed on my computer, I just don't know how to use it when compiling through the terminal.
By default, MobaXterm does not preserve Windows PATH environment variable: this is why you obtain
command not found
when running javac.
In order to tell MobaXterm to preserve Windows PATH, you just have to go to Settings --> Configuration --> Terminal tab and check Append Windows PATH environment variable option.
You can try cygwin first of all. Is another terminal that runs on windows.
With this command 'sudo apt-get install openjdk-7-jdk' at linux installs the jdk
And after this you can compile your program. sudo is for administration privilages.
Related
I know there are lots of posts similar to this, but all of their answers require creating an .exe file. I want to know how to run a program in a folder without installing java.
I don't want to install Java 8 as it breaks some of my programs. I want to run a java program in a folder using a start.bat file that points to the java.exe file in the same directory. Like this:
"java.exe" -jar program.jar
The error is like this:
Error: Registry key 'Software\JavaSoft\Java Runtime Environment'\CurrentVersion'
has value '1.7', but '1.8' is required.
Error: could not find java.dll
Error: Could not find Java SE Runtime Environment.
Since the command window is opened in the same directory, "java.exe" should point to the java runtime.
Can I maybe copy java.dll to the directory to make it work? How can I do this without installing java 8? Could I use java ME?
Why don't you create a .bat file that declares a new JAVA_HOME and appends to the PATH just for this DOS/batch session, then you can point to a place where you have the required JRE (however, you kind of have to install it... it's a Windows thing).
I understand you are reluctant to install the JDK/JRE 8 on your Windows because of this: "I don't want to install Java 8 as it breaks some of my programs". But trust me, you can always change the JRE version on the Java Control Panel (windows >> control panel >> Java) and change the JAVA_HOME & PATH environment variables, you might have problems with your browser's plugins though, the Java install will affect them as well.. I guess, in that, case you can either try to skip this part of the install process or.. install JDK 7 again afterwards?
IF you just want to run this program, you can also install VirtualBox and create a VM with windows and install the JDK8 there, avoiding any problems in your OS.
I'm in a Java I class and I have a new-ish laptop with Windows 8 on it. I've installed Java and changed the environment variables, created a Path, etc. When I enter java or javac in the cmd, it comes back with information. But when I enter "java-version" (as I'm instructed to do in the class to test if Java is working) it says, "'java-version' is not recognized as an internal or external command, operable program or batch file".
I've even attempted a HelloWorld program in spite of this, and as you can imagine, I got the same message. I'm not even able to change the directory.
Is there some special way to install this on Windows 8 or what?
You need to type java -version instead of java-version
First of all ensure you have typed Java -version space between Java and -version
No there's not special way to install Java on windows 8 machine, Just ensure that you have added ..\Java\jdk_(version)\bin and ..\Java\jre\bin in environmental variables.
Steps to be followed :
Right click on my computer go to properties
Then go to Advanced
system properties then click on environment variables
and add both path in Path variable under System Variables add semicolon between two paths
after all process don't forget to restart your PC
There is no special way to install java on windows 8. You can install java in normal way what you did in windows 7 or vista or windows xp and configure. Then run java -version, It will give your java version.
I've written a relatively simple java application. I have JDK on my PC, but I need it to run on a mac for school. The .jar runs perfectly on my PC, but I tested it on my Macintosh (which, BTW, does not have JDK installed).
Why isn't it running on mac? How can I fix this? Is fixing it even possible?
You don't need JDK to run Java based programs. JDK is for development which stands for Java Development Kit.
You need JRE which should be there in Mac.
Try: java -jar Myjar_file.jar
EDIT: According to this article, for Mac OS 10
The Java runtime is no longer installed automatically as part of the
OS installation.
Then, you need to install JRE to your machine.
Make Executable your jar and after that double click on it on Mac OS then it works successfully.
sudo chmod +x filename.jar
Try this, I hope this works.
I made the jar file executable as indicated by #Java D: sudo chmod +x filename.jar, and then I ran from the terminal Java -jar filename.jar as indicated in another answer by #Hardik Mishra. The installation process will start right after it.
Hi everybody.
The problem: elcipse-3.5.0 (Galileo) spits with an error when I try to launch it by clicking its launcher. The curse sound like this:
A Java Runtime Environment (JRE) or
Java Development Kit (JDK) must be
available in order to run Eclipse. No
Java virtual machine was found after
searching the following locations:
/home/emanemos/bin/eclipses/eclipse-3.5.0/jre/bin/java
java in your current PATH
However, everything goes smoothly when eclipse is started from console.
Before installing eclipse I've installed jdk1.6.0_16. I also created the $JAVA_HOME variable and changed my $PATH:
$ echo $JAVA_HOME
/usr/lib/java/jdk1.6.0_16
$ echo $PATH
/home/emanemos/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/java/jdk1.6.0_16/jre/bin
So that, my terminal got to know what java is:
$ java -version java version
"1.6.0_16" Java(TM) SE Runtime
Environment (build 1.6.0_16-b01)
Java HotSpot(TM) Client VM (build
14.2-b01, mixed mode, sharing)
Then a folder eclipse was extracted from .tar.gz package under the directory ~/bin/eclipses. I changed the folder's name eclipse to eclipse-3.5.0 and changed $PATH again:
$ echo $PATH
/home/emanemos/bin/eclipses/eclipse-3.5.0:/home/emanemos/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/java/jdk1.6.0_16/jre/bin
From this moment I was blessed to launch eclipse from console by the command eclipse.
However, I feel desperate about using the eclipse's application launcher.
Thanks in advance. I would be grateful for any help.
The message says "No Java virtual machine was found after searching the following locations: /Applications/eclipse/Eclipse.app/Contents/MacOS/jre/bin/"
I have solved it creating the folder /Applications/eclipse/Eclipse.app/Contents/MacOS/jre/bin and linking to the command at /usr/bin/java:
ln -s /usr/bin/java /Applications/eclipse/Eclipse.app/Contents/MacOS/jre/bin/java
Add this to eclipse.ini:-
-vm
$Java_home/jdk1.5.0_14/bin/javaw.exe
I could be off, but it looks to me that you don't have JAVA in your path. If you notice, you had to add it via the echo command. However, that only stays for that session of the terminal. You don't permanently affect the system. (I believe that's why you can launch from the terminal, but not via the launcher.)
Do you have the Java JRE actually installed on your system? If not, I would recommend doing that as that should do all the setup that you would need, then try running Eclipse again.
Edit: I noticed you said that you did install the 1.6 JDK. This should have fixed your problem. If Java is not in your path when you first open up your terminal, then that (I believe) is your real problem and you may need to do a reinstall or troubleshoot there.
(Making a big assumption that you're on Linux using X)
If you've installed the Java JRE without logging out and back in to the X session, the environment the session is in won't contain the $JAVA_HOME variable. It may just be a case of logging out and back in in order to get a new X session.
If you want to keep the same session running, you could try it out by pressing Ctrl+Alt+F9 to start another GUI session.
Fazil Baghirzade i solve the this problem
A Java Runtime Environment (JRE) or Java Development Kit (JDK) must be available in order to run Eclipse. No Java virtual machine was found after searching the following locations:
c:\Program Files\Eclipse\jre\bin\javaw.exe 'javaw.exe' in your current path
go to the "C:\Program Files\Java\jdk1.6.0_39" in this folder have "jre" folder copy it and paste the eclipse folder
thats all!!!
I'm trying to run SQuirreL SQL.
I've downloaded it and installed it, but when I try to run it I get this error message:
Java Virtual Machine Launcher.
Could not find the main class.
Program will exit.
I get the gist of this, but I have not idea how to fix it. Any help?
more info:
I'm on Windows XP pro.
I have java 1.6 installed, and other apps are running OK.
The install ran OK.
I believe I've followed the installation instructions correctly.
To run it, I'm invoking the squirrel-sql.bat file.
Update
This question: "Could not find the main class: XX. Program will exit." gives some background on this error from the point of view of a java developer.
Is Java installed on your computer? Is the path to its bin directory set properly (in other words if you type 'java' from the command line do you get back a list of instructions or do you get something like "java is not recognized as a .....")?
You could try try running squirrel-sql.jar from the command line (from the squirrel sql directory), using:
java -jar squirrel-sql.jar
The classpath is the path that the system will follow when trying to find the classes that you're trying to run. In the batch file you're trying to execute it probably has a variable like CLASSPATH=blah;blah;etc or a java command that looks similar to
java -classpath "c:\directory\lib\squirrel-sql.jar" com.some.squirrel.package.file
If you can find or add that classpath setting, make sure that it includes a path to the squirrel-sql.jar and any other jar files that it may depend on separated by semicolons (or the root /lib directory that may be included with the installation).
Basically you just need to tell java where to find the class files that you're trying to execute. Wikipedia has a more indepth discussion about classpath and can offer you more insight. http://en.wikipedia.org/wiki/Classpath_(Java)
JAVA_HOME variable must be set, to point to the prog files/java/version???/bin
open squirrel-sql.bat file with some text editor and see if the JAVA_HOME variable there is the same as the one in your enviroment variable
change it if it doesn't match....and than run bat file again
Have you followed these instructions:
http://www.squirrelsql.org/#installation
If so, are you running the batch file or the shell script to run it?
Tweaking MB's answer for windows, will get rid of the console window:
start javaw -jar squirrel-sql.jar
The .bat file does not seem to work.
Just double-click on:
squirrel-sql.jar
or type:
java -jar squirrel-sql.jar
in the command-line.
You can place .; in classpath in environmental variables to overcome this problem.
I tried to start SQUirrel 3.1 but I received a message stating "Could not find the main class Files\Rational\ClearQuest\cqjni.jar" I noticed that C:\Program Files\Rational\ClearQuest\cqjni.jar is in my existing classpath as defined by the Windows environment variable, CLASSPATH.
SQUirrel doesn't need my existing classpath, so I updated the SQUirrel bat file, squirrel-sql.bat.
REM SET SQUIRREL_CP=%TMP_CP%;%CLASSPATH%
SET SQUIRREL_CP=%TMP_CP%
It no longer appends my existing classpath to its classpath and runs fine.
I had this problem when I "upgraded" to Windows 7, which is 64-bit. My go to Java JRE is a 64-bit JVM. I had a 32-bit JRE on my machine for my browser, so I set up a system variable:
JRE32=C:\Program Files\Java\jre7
When I run:
"%JRE32\bin\java" -version
I get:
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) Client VM (build 24.51-b03, mixed mode, sharing)
Which is a 32-bit JVM. It would say "Java HotSpot(TM) 64-Bit" otherwise.
I edited the "squirrel-sql.bat" file, REMarking out line 4 and adding line 5 as follows:
(4) rem set "IZPACK_JAVA=%JAVA_HOME%"
(5) set IZPACK_JAVA=%JRE32%
And now everything works, fine and dandy.
I had the same issue with a different application (BI Publisher) because I installed a 32 bit version of this application on a 64 bit version of Windows.
Java Virtual Machine Launcher - could not find the main class
The solution for my case was to tell BI Publisher where to find the x86 version of JRE: