I have 3 java in my system 1.6, 1.7 and java 8.
I set my JAVA_HOME and path to 1.7, but when I run java -version using cmd administrator mode it return me 8.
Could anyone please tell me from where cmd pick java, and how i can change it to another version.
Updated: I already set java 7/bin in path variable
Start your cmd shell and type echo %PATH%.
OS would inspect listed directories and the first one that has java binary will be the one being used.
To change it - the PATH variable is set based on the settings in Control Panel -> System -> Advanced System Settings -> Environment Variables. You'd need to start a new cmd session to see updated changes.
When we run cmd as an administrator then it pick java.exe which is already available under C:/user/windows32 folder.
To resolve this issue, instead of appending my java at the end of the path, append in the starting of the path vaiable.
So here is the code used in cmd if run as administrator
set path=%JAVA_HOME%/bin;%path%;
java -version
Related
I have installed multiple versions of JDK, including 1.6,1.7,1.8.
I want to know which version of java.exe gets executed when I run software that needs JRE. I did some testing, see below:
Tests:
cmd.exe command: echo %java_home%
prints: java version "1.8.0_31"
cmd.exe command: java -version
prints: java version "1.8.0_31"
Then I checked the register table in HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit\1.8 and got the javaHome key value
result: C:\Program Files\Java\jdk1.8.0_31.
java code: System.out.println(System.getProperty("java.home"));
prints: C:\Program Files (x86)\Java\jdk1.7.0_15\jre
Finally, I opened the task manager, searched the java.exe process and located the java.exe directory at:
result: C:\Program Files (x86)\Java\jdk1.7.0_15\bin
Question:
I'm confused which jave.exe file the computer chooses. Can you help?
Passive approach
You may want what the where windows command line utility does; assuming you have only one java.exe in your %PATH%
Try:
where java.exe
If you have multiple version of java pin your %PATH% this will return multiple values. (unfortunately)
Active approach
Set your environment this way:
Have your PATH environment variable to point ONLY to c:\tools\java\default
Store all your jre in one folder like
C:\tools\Java\JRE_1.6
C:\tools\Java\JRE_1.7
C:\tools\Java\JRE_1.8
Then open a comman propt and inside C:\tools\Java\ execute
junction default JRE_1.6
This will create a junction (wich is more or less like a symbolic lync).
In this way you will always have your default java in c:\tools\java\default.
If you then need to change your default java to the 1.8 version you just neet to execute
junction -d default
junction default JRE_1.8
From information you provided your default java is set to java 8 and the program you run is like to be run in some ide that use java 7.
Java -version command gives the default set java in your system.
I have to convert my Matlab algorithm in Java. For this I'm using matlab builder ja toolbox, after following all the necessary steps, the build fails and this error is displayed:
'javac' is not recognized as an internal or external command, operable program or batch file. Error: An error occurred while shelling out to javac (error code = 1). Unable to build executable.
When typing java -version in the matlab command line, this is what i get:
Java 1.6.0_12-b04 with Sun Microsystems Inc. Java HotSpot(TM) Client VM mixed mode
It means I should have this compiler of java installed on my computer, only then the matlab builder ja works. I'm new to Java, I'm not sure what compiler I should be looking for.
First make sure you have installed jdk and jre, both are installed with the java software development kit. The installation folder is typically C:\Program Files\Java.
Now go to Computer > Properties > Advanced system settings in the advanced tab click on Environment Variables
In System variables find the variable named Path, in the value of Path you will find a java path like C:\ProgramData\Oracle\Java\javapath, just change it to C:\Program Files\Java\jdk1.x.x_x\bin.
Hope that helps.
If you want javac (the compiler), you'll need to download the Java Development Kit (JDK), not just the Java Runtime Environment (JRE). Note that the JDK includes a JRE.
This tutorial give instructions to install JDK to your computer.
You need to make sure that Java SDK is installed and also PATH is set properly so that windows would be able to know where the executable is. Detailed steps on how to debug this issue is explained here: http://www.windows-commandline.com/javac-not-recognized-internal-external-command/
To solve the aforementioned problem follow the mentioned steps:
1) Copy the address location of your Java\jdk\bin folder usually installed in your C: drive. It should look something like this:
C:\Program Files (x86)\Java\jdk1.8.0_65\bin
2) Right click on My Computer-->Properties-->Change settings-->
Advanced-->Environment Variables.. -->New..
3) Now,
Set Variable name: PATH
Variable value: C:\Program Files (x86)\Java\jdk1.8.0_65\bin
4) Press OK, re-open your cmd and compile your program.
Hopefully it worked!
Path is defined as the filename. Ex, C://aklsej;dlfkj/blahblah
You will need to specify the full path in the system control panel, advanced system settings, edit variables, edit path, put a semicolon after the last entry and don't delete anything, and then add the full path wherever you installed java to.
to make this easy, do a search for javac in the search panel and then just add the full path to the environmental variables from there.
Set Following Environment Variables
It will works
JAVA_HOME=C:\Program Files\Java\jdk1.7.0_09
set PATH=%JAVA_HOME%\bin
Download Java from given link according to your requirements.
http://www.oracle.com/technetwork/java/javase/downloads/index.html
then follow below steps:
Step-1 : Right Click on MyComputer and click on properties .
Step 2 : Click on Advanced tab
Step 3 : Click on Environment Variables
Step 4 : Create a new class path for JAVA_HOME
Step 5 : Enter the Variable name as JAVA_HOME and the value to your jdk bin path ie c:\Programfiles\Java\jdk-1.6\bin and
NOTE Make sure u start with .; in the Value so that it doesn't corrupt the other environment variables which is already set.
Step 6 : Follow the Above step and edit the Path in System Variables add the following ;c:\Programfiles\Java\jdk-1.6\bin in the value column.
Step 7 :Your are done setting up your environment variables for your Java , In order to test it go to command prompt and type
java
who will get a list of help doc
In order make sure whether compiler is setup Type in cmd
javac
who will get a list related to javac
Hope this Helps !
If you receive this error, Windows cannot find the compiler (javac).
Here's one way to tell Windows where to find javac. Suppose you installed the JDK in C:\jdk1.8.0. At the prompt you would type the following command and press Enter:
C:\jdk1.8.0\bin\javac HelloWorld.java
If you choose this option, you'll have to precede your javac and java commands with C:\jdk1.8.0\bin\ each time you compile or run a program. To avoid this extra typing, consult the lecture "Creating a Hello World application" in this website
Class names, 'HelloWorld', are only accepted if annotation processing is explicitly requested
If you receive this error, you forgot to include the .java suffix when compiling the program. Remember, the command is javac HelloWorld.java not javac HelloWorld.
I did the following steps but java does not seem to be working for me, do I need to restart my system if yes then why?
1. Right click My Computer->Advence Option->Environment Varibles->System Variables
2. variable : Path->Edit
3. Copy your jdk bin directory i.e.C:\Program Files\Java\jdk1.7.0_51\bin
4. Paste it after putting a semi-colon(;) in value section
i am getting below error while running java in cmd
C:\Users\User>java -version
Error: opening registry key 'Software\JavaSoft\Java Runtime Environment'
Error: could not find java.dll
Error: Could not find Java SE Runtime Environment.
No, but you will need to close and recreate any cmd windows, running java programs, or the like.
To check it's correct, open a new cmd window and type set -> review the information for PATH and JAVA_HOME.
You should set two things:
JAVA_HOME
PATH
The first lies under the "User variables for [your user name]" section. Add the JAVA_HOME variable and set it to where your jdk is installed. i.e. C:\Program Files\Java\jdk1.7.0_51\
The second lies under the "System variables" section. You should find the "path" variable, and edit it. Then, append ";%JAVA_HOME%\bin" (minus the quotes) to the end of the path variable.
After you have done this, save the variables and close that window clicking the "ok" button. Close down all instances of the command prompt (and any IDE you may be developing with such as Eclipse or NetBeans), and reopen one command prompt. Then, if you would like to test whether or not your changes worked and are in effect, try the following:
echo %JAVA_HOME%
This should output where you set your java home variable to.
echo %PATH%
At the end of what is output, you should see your java home\bin addition to the path variable
java -version
If you can run this command from the command line, it means that your environment was set up correctly and java is now in your path.
Not necessary. Quit and Open the command prompt again (if any) that runs the java process and type java -version to check if it installed successfully.
If you are using mac, source ~/.bashrc or source ~/.zshrc should refresh your environmental variable. No need to re-start the terminal even.
No, you don't need to restart your system.
However, you have to restart your command prompt application to update the changes done on Environment variables.
NO.
You don't need to restart the system, but just the application like cmd or any IDE you are using for java development (i.e Eclipse) need to restart.
And to confirm that the java path is set that you have mentioned in JAVA_HOME environment variable, you can open cmd and you can check with commands echo %JAVA_HOME% or echo %PATH%.
I reinstall the JDK and set the JAVA_HOME and PATH variable again. now it's working.
In my case under user variable section(for particularuser) JAVA_HOME set to jre not jdk path . I change it to JDK path , It worked for me
yes need to restart cmd prompt after env variable change
What I'm trying to do is running a .java source by compiling and running it from command prompt (not using any IDE) using commands javac and java and the program connects with MySQL, so everytime I run the program from cmd, I need to specify path of the MySQL connector using -classpath switch of java. And entire command to run the program gets something like below:
java -class .;path/to/connector/mysql-connector.jar MySQLConnect
where I want it to be as simple as for other programs like java MySQLConnect
and it should run the program.
Is there any way I can add the connector's path to environment variables of Windows that java make use of it. I already tried by creating a new CLASSPATH variable in Windows environment variables and added absolute path of the connector with file name along, but that didn't worked.
Please provide me the workaround of this Windows and Ubuntu as well.
Thanks.
WIndows : Copy mysql-connector.jar to C:\Program Files\Java\jdk1.6.0\jre\lib\ext
and copy the same file to C:\Program Files\Java\jre1.6.0\lib\ext
go to My Computer -> Properties -> Advanced -> Environment Variables
Set these paths
JAVA_HOME
C:\Program Files\Java\jdk1.6.0
PATH
C:\Program Files\Java\jdk1.6.0\bin;
CLASSPATH
.;C:\Program Files\Java\jre1.6.0\lib\ext\mysql-connector.jar;.;
open a fresh command propmpt
type
java -version press Enter
WINDOWS
Go to My Computer -> Properties -> Advanced -> Environment Variables
then find CLASSPATH variable in System variables and click on edit to add your jar file there.
LINUX or MAC
In your shell use a variable CLASSPATH in your .bashrc or .profile to set a default class path.
Set classpath=%classpath%;location of mysql-connector with connector file name.jar. For example:
set classpath=%classpath%;D:\TECHNICAL\JAVA WORLD\JDBC\mysql-connector-java-5.1.18-bin.jar;
D:\TECHNICAL\JAVA WORLD\JDBC\ is the location of mysql-connector.
To set this path go to Advanced System Settings->Environment variables->User variables->CLASSPATH->Edit, then type set classpath=%classpath%;D:\TECHNICAL\JAVA WORLD\JDBC\mysql-connector-java-5.1.18-bin.jar; and finally press OK.
I have done in this style. After that, I got result of programs correctly. Then there is noCLassNotFoundException.
I downloaded this Java JDK and installed it.
But when I go to the command prompt to check the version, it says it's not recognized.
Is anyone else experiencing this issue with the latest Java?
I might not have installed the right version. I need the java that works with grails
C:\>java
'java' is not recognized as an internal or external command,
operable program or batch file.
C:\>java -version
'java' is not recognized as an internal or external command,
operable program or batch file.
C:\>
when i do a search on my computer for java, it does not find anything
Windows 2k8 R2 server-
For both java [-option] or %JAVA_HOME% to work in the command line you need the following:
In Control Panel->System and Security->System->Advanced system setting->Advanced->Environment Variables->System Variables
Edit the Path variable and add a ";" after the last value and add the the path to the Java bin directory:
e.g.- C:\Progra~2\Java\jre6\bin\
Add the JAVA_HOME Variable with the value set to the path for the java executable:
e.g.- C:\Progra~2\Java\jre6\bin\java.exe
Press simultaneously the "windows" and "pause" buttons on your keyboard, this will bring up the System Preferences dialog.
In the Advanced tab, find Environment Variables.
Then, in the User (upper) section, create or update the following two variables :
JAVA_HOME = where you put your JDK, eg. C:/Java/SDK
PATH = %JAVA_HOME%/bin
Close the dialogs.
Then, in a new command-line console, try "javac -version" and see if it's detected.
It's important that you use a new console, because environment variables are read only when the console is launched.
Java is typically installed (on Windows) as C:\Program Files\Java\jdk<version>
That installation directory has a subdirectory bin which you need to append to your PATH environment variable via the control panel. Then, the commands like java, javac etc. will be available on the command line.
BTW, the same is true for Grails.
Is the -version flag not recognized, or is the "java" command not recognized? One way to test this is just to type 'java' by itself and run it and see what happens.
If the command is not recognized, make sure that the JDK's install path is in your windows PATH. If not, you won't be able to use any of the java executables from the command prompt. Here's another link that may help out.
You need to manually add the path to javac.exe and java.exe to your operating system path. The Java installation program doesn't do that for you.
You most likely don't have java.exe in your system's PATH variable.
For Linux:
check $PATH and $JAVA_HOME. You can configure it in /etc/environment
From console you can check it like:
$ echo $PATH
For Windows:
My Computer -> Properties -> Advanced -> Environment Variables
Check there PATH.
From console you can check it like:
echo %PATH%
You should have a Java icon in Windows Control Panel. Locate the Java tab and click the View button. That will show you the path to the Java executables.
Last but not least, make sure you have restarted the computer so changes in the PATH variable can take effect.
You installed the JDK. Isn't java.exe part of the JRE? Do you have that installed?
Maybe your system variables in the environment variables are not set properly. Follow the steps in the link below. Finally, make sure the path component in system variables has only one JDK path. Delete other JDK paths that you won't use.
https://docs.oracle.com/javase/tutorial/essential/environment/paths.html
You might have installed a previous or older version of Java so you can just uninstall it and directly download JDK from Java JDK
I was also facing the same issue but when I downloaded and installed the latest version the issue was resolved.
Also uninstall any other Java versions which may be present in the program files.
To get to know other versions which may be present in your computer use Windows File Explorer to go to:
Files > Windows C > Program Files > Java
All the JDK and JRE you have will be listed there. Uninstall any other Java versions other than what you installed. And then make sure you have set the path variable of the JDK.
For me, it was incorrect line in the PATH
(1) Check PATH: Type "Edit System Environment Variables" on the search -> System Properties -> Advance -> Environment Variables -> System variables -> Path
(2) On the list, mine was C:\Program Files (x86)\Common Files\Oracle\Java\javapath so I just add \ at the end (the exe files in the javapath folder)
OS: Windows 10 64 bit
IF you set the PATH and it's not showing up in cmd when you run %PATH%, try restarting your computer.