'javac' is not recognized as an internal or external command

Question

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.

Bouncy

possible duplicate of javac is not recognized as an internal or external command, operable program or batch file – Randirandie

@OlegEstekhin, I'm all in favour of closing questions as duplicates (which this one visibly is), but the duplicate target you suggest is closed as off-topic unfortunately (I don't think it is off-topic, however easy the question is for a Java developer). – Majolica

Than either all "javac is not recognised" questions should be closed as off-topic or the most useful of these question can be un-off-topiced and made into a canonical. – Randirandie

@OlegEstekhin, you're absolutely right. There's a few of them on the topic around it seems. Not quite sure which one suggests installing the JDK first, though. – Majolica

... unfortunately, I don't have time to hunt for the right one right now. – Majolica

Unfortunately JRE != JDK – Secure

@okiharaherbst, Thanks for the comment. Your comment gave a new path to my trial and I could overcome the issue successfully. Thanks! – Nomination

docs.oracle.com/javase/tutorial/getStarted/problems/index.html – Andra

Did you solve the problem? mark the answer accepted that solved your issue. – Impletion

Answer 1

• 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.

Hachman

Answer 2

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.

Majolica

In addition to this, if you DO have the JDK downloaded, verify that you have a JAVA_HOME environment variable set pointing to the root JDK folder and have added %JAVA_HOME%/bin to your PATH. – Mishnah

well i'm finding the jdk but i don't know which jdk it is? will it be jdk 1.6? because there alot of jd kits available.. – Bouncy

The latest version from Oracle is Java 8. Java 7 is still maintained for a little while. Java 6 is no longer supported (you should in fact upgrade the JRE you have since it's a rather old version). Only use Java 6 if you know the tools you're using aren't compatible with more recent versions. – Majolica

and how will i add jdk to my path? and how will i set JAVA_HOME environment variable pointing to the root JDK folder. if u can guide me with the procedure, it'll be very kind of you :) – Bouncy

no, @bruno i've to download the Java 1.6.0_12-b04 with Sun Microsystems Inc. Java HotSpot(TM) Client VM mixed mode nothing else, i mean a recent version isn't supported.. :( – Bouncy

What are you talking about? Is Matlab not supporting it? Anyway, if you really need an older version you can still get it from the archives. – Majolica

yes @bruno matlab isn't supporting the newer versions. by matlab i mean matlab r2009b. – Bouncy

sorry, i know i'm asking very silly sorta questions, but as i mentioned earlier, i've never used java.. so i don't know what these terminologies mean.. is java development kit 6u12 the required kit i'm finding? i'm looking for java 1.6.0_12-b04 with Sun Microsystems Inc. Java HotSpot(TM) Client VM mixed mode @bruno hope u ppl will answer my quesion :) – Bouncy

Yes, Java 6 and 1.6 are the same thing. 6u12 is the same as 1.6.0_12. – Majolica

Answer 3

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/

Eugeniaeugenics

Answer 4

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!

Escapement

New user variable or new system variable? – Fossil

Answer 5

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.

Roryros

Answer 6

Set Following Environment Variables It will works

JAVA_HOME=C:\Program Files\Java\jdk1.7.0_09
set PATH=%JAVA_HOME%\bin

Outgoing

Answer 7

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 !

Delorisdelorme

Answer 8

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.

Infeasible