Setting up Java compiler on Windows laptop - java

I have a laptop with a Windows 7 OS 64-bit. I'm trying to set up the Java compiler so when I type in "javac" in the command prompt, it will compile the Java file I want. I've had it done on my laptop before but someone did it for me. They went to the Environment Variables under the Advanced System settings, then edited the "PATH" so that it would recognized the compiler. So I did the exact same thing, I copied the file location of javac from ProgramFiles, and put it in PATH. It still does not compile my Java files. It says:
"javac" is not recognized as an internal or external command.
And before you ask, I did search through other forums on this site to see if there was an answer that can help. There are similar situations to mine but the solutions did not help me.
As of now, this is the file path that I tried copying into PATH:
C:\Program Files\Java\jdk1.7.0_25\bin This leads to a file marked javac. So far I'm still unsuccessful with setting up the compiler.

It looks correct. Did you restart the Command prompt every time you changed the PATH variable ? Also there's supposed to be only one path variable, so you're supposed to edit the existing one, entries are separated by a semi-colon (;).

Related

cannot execute java class from bash script and also updatd the java_home to higher version and compiled the class in the lower version than mentioned

I had SunOs 5.10 unix server , where i had written a script to execute a java file which is as below
#!/bin/ksh -x
export JAVA_HOME=openjdk1.8.0_331/bin
$JAVA_HOME/java com.myclass.MyClient
in this script there is alot of code which includes log file, and other binaries class path added before exporting JAVA HOME. But when i am executing i am getting the below error
openjdk1.8.0_331/bin/java : Cannot execute
i had changes lot of java versions but getting the same error
Your JAVA_HOME is not an absolute path. This is broken; many tools will just fail when you do this. Just make it an absolute path. It may or may not explain your error, but it's a ticking timebomb.
JAVA_HOME cannot be bin; its the level above bin.
It looks like you're using JAVA_HOME as an ersatz script variable to make your script work, but this is wrong: JAVA_HOME is used by all sorts of tools and has a very specific meaning, and it's not whatever you think it is.
There are 2 obvious explanations for your error:
Some tool sees JAVA_HOME, attempts to run java based on this, and fails, because your JAVA_HOME is broken. There's a ton of infra that is 'custom' per OS, and it may well be that the SunOS setup didn't fail if you set JAVA_HOME to broken values, but it does fail here. The fix is to not have broken JAVA_HOME, not to start looking for a setup on your new OS that can deal with broken JAVA_HOME settings. In other words, your script was always broken, it just so happens that your specific set up on that specific server on that specific version of sun OS so happened to be capable of dealing with the mess.
A much simpler explanation is also possible: That executable does not run on your OS+Architecture combination. trivially testable: Do NOT set JAVA_HOME at all and just try to run that java executable by e.g. cd ing to the path and running ./java -version. See what happens. If that also gives you cannot execute, voila - the script isn't the problem (though it still has a broken JAVA_HOME you should be fixing), you need to install a JVM that works on your OS+Architecture.

"Javac" doesn't work correctly on Windows 10

the problem is that I upgraded to Windows 10 and now I'm installing my tools to programming and now that I installed the JDK 7 of Java, when I try to use in the cmd the command:
- "javac"
The result of this is: "javac" is not recognized as an internal or external command...
But I was edited the PATH with the correct link of jdk, because when I use "java", it is ok.
Now, I tried in the console with this command: PATH=%PATH%;"C:\Program Files\Java\jdk1.7.0_79\bin"
And when I executed the command "javac" it works, but now, when I open other console, it doesn't work, or when I restart the console, this command is not recognized.
What could be the problem?
java is part of the JRE, not the JDK.
You need to add the JDK bin to the system PATH, in
"Control Panel" | System | Advanced | "Environment Variables"
Her's how I configure System variable on Windows 10 :
I am totally new to java and spent hours trying to get the problems with PATH and CLASSPATH worked out. There was one person who said to restart the command prompt after you modify the environment variables; that was it for me. While you are testing different configurations, make sure to relaunch the command prompt before testing. It seems like there are at least 2 different ways of setting this up. I went with the following:
1) In System Variables, add
JAVA_HOME = c:\program files (x86)\java\jdk1.8.0_121
2) In System Variables, add the following to existing Path...
%JAVA_HOME%\bin
That's it.
No need for quotes around anything. No double forward slashes or anything else. I think it would also work if I removed the java_home variable and just listed the explicit path to bin in the PATH variable, but I'm not touching it again now that it finally works.
After adding C:\Program Files\Java\jdk1.8.0_73\bin to the system variables I turned off my command prompt and opened another one. Then it worked.
Maybe a bit late, but i had same problem.
Click on "Move up" button for Java path and move it at top.
It fixed problem for me
just add C:\Program Files\Java\jdk1.7.0_80\bin as the path in environmental variables. no need to add java.exe and javac.exe to that path. IT WORKS
I added below Path in environment variable
;%JAVA_HOME%/bin instead of %JAVA_HOME%\bin
in my case , it fix the problem
I had the same issue on Windows 10 - the java -version command was working but javac -version was not. There are three things I did:
(1) I downloaded the latest jdk (not the jre) and installed it. Then, I added the jdk/bin path tan o environment variable. In my case, it was C:\Program Files\Java\jdk-10\bin. I did not need to add the ; for Windows 10.
(2) Move this path to the top of all the other paths.
(3) Delete any other Java paths that might exist.
Test the java -version and javac -version commands again. Voila!
For some reason it worked for me to add quotation marks to the path folder on windows 10. not C:\Program Files\Java\jdk 1.8.0_111\bin, but "C:\Program Files\Java\jdk 1.8.0_111\bin".
now i got it finally! make sure that there are no spaces before and after the path and put the semi-colon on both sides without spaces
The PATH is for current user, instead you can add a CLASSPATH and below link would help you more PATH and CLASSPATH
I added below Path in environment variable
C:\Program Files\Java\jdk1.8.0_91\bin
and then compiled the program but got the error then I restarted the system and again compiled the program
This time it worked :)
Add java path to environment variables and move it to the top of all the paths available there. It worked for me.
To be sure about your path, you can use double quotes " to locate the path or if you are in Windows, you can browse to path to select "C:\Program Files\Java\jdk1.8.0_121\bin" folder.
in the search window type 'environment variables' this should give you a link to editing the variables. On the variables editing page there is an upper section and a lower section in the lower section add NEW,type path C:\Program Files\Java\jdk-10\bin this worked great for me and it finds the compiler all the time.
Kind of beating a dead horse now but, I want to clarify one thing that may not be quite so obvious. Yes indeed you need to edit the PATH environment variable as already stated many times. The key for me was to edit the PATH under SYSTEM variables. I had inadvertently edited the PATH under USER variables. Why did this matter? On my machine I have to log in as an Administrator to edit environment variables. So editing the User variables was not helping because I run the command prompt under my login (non-admin) account. Grrr!
Also, I found that closing the command prompt window, and re-opening it after the PATH variable update was required. Changing the order of the values, adding semi-colons, etc. didn't make a difference for me.
Cheers
If you have set all PATH variables correctly after installation, just restart it.
I had the same problem, I had also installed new Windows7 OS then I upgraded it to Win 10. Then i started setup necessary tools like IntelliJ, Java jdk,jre, eclipse so on.
In cmd, java -version worked but javac compiler got unrecognized. I checked and all good, the files in the folders, path are correct and so on.
I restarted and checked it again in cmd ,it worked.
what I did is:
I typed ; accidentally in front in the path variable and then hit OK, after this if I again edit it was nowhere going to the same page as earlier, it opened a new page as defined for user variables and then I was able to remove double quotes in front of the PATH VARIABLE.
Everything worked fine then. :)
Did it just now.
Add
PATH = C:\Program Files\Java\jdk1.8.0_66\bin
in Advanced system setting. Then Choose Environment Variable.
for windows 10 Users Use Java path( JDK Bin location) AS "C:\Program Files\Java\jdk-9.0.1\bin" it will work.
Points to remember, do as the image shows. Move the highlighted bar up using move up button, this will help.

Trouble in Setting Java Environment Path on Ubuntu (libjvm.so: cannot open shared object file: No such file or directory)

Found the solution!
Ubuntu by default ignore the command "RD_LIBRARY_PATH" therefore I need to add those codes in ".bashrc" instead of "/etc/environment" or .profile.
it now work perfectly fine!
I am trying to run a program that reads Java method from C/C++ code. (I made it on Windows successfully, now, I am working on Linux)
I made it successfully compiled and run on Ubuntu, however, the problem is..
Whenever I try to run the program, I have to type following commands on terminal..
source /etc/environment
./invoke #program name is invoke
If I do not type "source /etc/environment" every time I boot my PC, the error message I get is...
error while loading shared libraries: libjvm.so: cannot open shared object file: No such file or directory
Ok. Here is what I added in /etc/environment
export PATH="$PATH:/usr/lib/jvm/jdk1.7.0_25_x64/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_25_x64
export LD_LIBRARY_PATH=$JAVA_HOME/jre/lib/amd64:$JAVA_HOME/jre/lib/amd64/server
What I want is that, as you know, I want to run the program without typing "source /etc/environment".
I also tried typing those PATHs on /etc/profile, but result was same... I should type "source /etc/profile" every time I reboot my PC..
How to make it permanently applied to whole range of System without typing "source /etc/environment" stuffs everytime I boot?
if you need to see source code of the program, here is downloadable address:
http://cfile237.uf.daum.net/attach/247819495212DF1C07B9EB
This worked for me:
For x86:
export LD_LIBRARY_PATH=/usr/lib/jvm/default-java/jre/lib/i386:/usr/lib/jvm/default-java/jre/lib/i386/server
For x86_64
export LD_LIBRARY_PATH=/usr/lib/jvm/default-java/jre/lib/amd64:/usr/lib/jvm/default-java/jre/lib/amd64/server
I had the same problem of setting the path(permanently) however I was using Red Hat, If you look change PATH permanently on Ubuntu it might help you. There was a file on Red Hat .profile that once you add your exports statements, they will get loaded when the computer starts. :) There should be the kind of file for ubuntu
export PATH="$PATH:/usr/lib/jvm/jdk1.7.0_25_x64/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_25_x64
Put "-Djava.library.path=FULL_PATH_HERE/jre/lib/amd64" as a JVM option in your C code.
Edit the full_path_here part.
The path is allowed to be relative, but I don't think you can use $JAVA_HOME as a placeholder for the environment variable.
Found the solution!
Ubuntu by default ignore the command "RD_LIBRARY_PATH" therefore I need to add those codes in ".bashrc" instead of "/etc/environment" or .profile.
it now work perfectly fine!
add the path of the missing libraries in the file /etc/ld.so.conf
execute the following command: ldconfig
this way, you'll add the new libraries to the default ones.
To check whether the new libraries have been linked,
execute the following command: ldconfig -p
to have the list of libraries currently linked by default.

setting up classpath. javac is not recognized

I am trying to run my java program from command line.
I read an article about setting up classpath, but I get an error of javac is
not recognized as internal or external command. What should I do? (I dont want to set a permanent CLASSPATH)
This is what I have done in my command line
D:\user> set path=%path%;C:\Program Files\Java\1.7.0_07\bin
D:\user> cd testing
D:\user\testing> javac firstProgram.java
'javac' is not recognized as an internal or external command,
operable program or batch file.
Thank you
Assuming that the PATH is correct1, the most likely cause is that you have a JRE installation ... and a JRE doesn't include a java compiler. You need a JDK installation if you want to compile from the command line.
(You can confirm this by looking in the C:\Program Files\Java\1.7.0_07\bin directory to see if it contains a javac.exe file. A JRE won't ...)
Where can I find the Java compiler to download..
You need to download one of the JDK installers; see http://www.oracle.com/technetwork/java/javase/downloads/index.html
1 - I don't think quotes are required in a PATH variable on Windows. At least that's what various examples that Google found for me seem to imply. But I've never really understood the logic behind quoting in Windows ...
Its an issue related to Program Files.
First make sure that your JDK Folder is installed in Program Files or Program Files(x86) or any other folder.
Then you should use the path of bin folder in " ". Because command prompt does break the string at space. When you will write it in " " then it will take is as a whole String.
You try these commands
set path=%path%;"C:\Program Files\Java\1.7.0_07\bin"
or
set path=%path%;"C:\Program Files(x86)\Java\1.7.0_07\bin"
It might help you to get out of this.
Better do it in Environmental variable and check it!
try below command is recognized from command prompt
C:\Program Files\Java\1.7.0_07\bin\javac ab.java
This is just to verify your javac
Here's how you can set the path temporary, meaning if you close and reopen "command prompt" you will have to set the path again.
Assuming the path is C:\Program Files\Java\jdk1.6.0\bin
TYPE IN C:\Program Files\Java\jdk1.6.0\bin AND HIT ENTER
that's it.
The commands D:\user> set path=%path%;C:\Program Files\Java\1.7.0_07\bin works well for me
Adding few more information to this:
Please check the version of JDK and JRE installed on your computer. Recently I faced the same problem even after setting the PATH. It gives the error "javac - command is not recognised"
Solution is there must be similar versions of JDK as well as JRE
E.g.: JDK 1.7.75 along with JRE 1.7.75

regarding javac

javac is not internal or external command error is coming. I have set the path. then also it is giving the same error.
Are you sure you installed the JDK?
The JRE (aka "Java Runtime") does not contain javac, this is only part of the JDK ("Development Kit")
You should first examine the PATH by executing this command:
echo %PATH%
Among these folders should be at least one that looks similar to this:
C:\Program Files\Java\jdk1.6.0_20\bin
Maybe you left out the bin at the end, maybe there isn't such a folder name at all in your PATH? We cannot know. If you tried this and are still unsure, post the value of the PATH so we can give you real tips instead of just guessing.
If you're on windows, and running from a command prompt you need to reopen it to force any PATH changes to take effect

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