I've just istalled JDK8 on PC Windows 11 Home
Now im trying to run simple default program from NetBeans14
In environmental variables:
PATH : C:\Program Files\Java\jdk1.8.0_202\bin
CLASSPATH : C:\Program Files\Java\jdk1.8.0_202\bin
Project build on hard disk
C:\Projects\Hello\src\main\java\pack\hello
on cmd going tn cd C:\Projects\Hello\src\main\java\pack\hello
javac compiles .java file on .class file
command "java Hello" output: Error: Could not find or load main class Hello
Hello.class is there.
checking commands, all works:
java
javac
javac -version
Please to support, or send some similar problems posts.
All web answers are speaking about setting PATH and CLASSPATH, where in my case it already took place.
Thanks in Advance
I tried to follow your steps. I downloaded and installed the newest JDK 8 on Windows 11, and NetBeans 14.
Then I looked through the Environment Variables, and the only mention of Java was in the system Path variable:
You see, I have no CLASSPATH variable, nor haven't I manually set anything. Everything was installed automatically. I have no explicit path to C:\Program Files\Java\jdk1.8.0_... in my Path variable.
And I created a simple app in NetBeans. It runs from NetBeans successfully. Just do "Run Project" (F6) in the NetBeans interface.
If you need to run it from the command line for some reason, this question may help.
If you need to run it on another computer, I would advise you not to do it with cmd. Compile it into jar, then wrap it into exe (in case of Windows) using launch4J.
I am building a project in Java.
I have this error:
Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre6\lib\tools.jar
I have installed a JDK and the folder: C:\Program Files\Java\jre6\lib is in my system but the file tools.jar is not there.
Yes, you've downloaded and installed the Java Runtime Environment (JRE) instead of the Java Development Kit (JDK). The latter has the tools.jar, java.exe, javac.exe, etc.
In case this is still an issue for anyone, I have a bit of clarification on the previous answers. I was running into this same issue using ant with only a JDK installed. Although, the JDK installer gave me a directory structure like this:
Directory of C:\Program Files\Java
05/08/2012 09:43 AM <DIR> .
05/08/2012 09:43 AM <DIR> ..
05/08/2012 09:46 AM <DIR> jdk1.7.0_04
05/08/2012 09:19 AM <DIR> jre6
05/08/2012 09:44 AM <DIR> jre7
0 File(s) 0 bytes
and when I ran ant, it complained about not finding tools.jar under the jre7 subdirectory. It wasn't until I set "JAVA_HOME=C:\Program Files\Java\jdk1.7.0_04" that the error went away.
Install the Java SDK.
Add a System Environment Variable called JAVA_HOME with the value of JDK location.
Go to Control Panel\System and Security\System. Advanced System Settings, Environment Variables, System Variables, New... Example:
Variable Name:JAVA_HOME
Variable Value: C:\Program Files\Java\jdk1.7.0_21
Close/reopen your CMD window so that the new variable takes effect before attempting to re-run the ant command.
I had the same problem and copying C:\Program Files\Java\jdk1.6.0_26\lib\tools.jar to C:\Program Files\Java\jre6\lib\ext worked for me
If you have installed JDK 9.0.1 you will also have this problem as the tools.jar has been deprecated. See migration document.
Set your JAVA_HOME environmental variable to point to C:\Program Files\Java\jdk1.7.0_02.
If you are in Linux you can solve this by installing java on the system:
sudo apt-get install openjdk-7-jdk openjdk-7-jre
No, according to your directory structure, you have installed a JRE, not a JDK. There's a difference.
C:\Program Files\Java\jre6\lib
^^^^
It should be something like:
C:\Program Files\Java\jdk1.6.0_24
Don't spend too much time looking for tools.jar. If you get an error like that, don't be upset.
If you already have java JDK 1.5, go to your lib folder, and the tools.jar should be available there. Copy and paste it in your ant bin folder, then try to use the command ant -version.
You should see the expected result.
I had the same issue on a linux machine. I was quite frustrated at first, because I have installed both the JDK and JRE. I am using version 1.6, 1.7 and 1.8 simultaneously, and I have played a lot with the alternatives to have everything set properly.
The problem was quite stupid to solve, yet counter-intuitive. While I was using the correct JDK, I paid attention to the path of the tools jar maven complained about - it was expecting it to be
$JAVA_HOME\..\lib\tools.jar
The $JAVA_HOME variable pointed directly to my jdk folder (/usr/local/java which was also the correct $PATH entry and alternative sym link). It actually searches for the lib folder outside the java directory, because:
$JAVA_HOME\..\lib\tools.jar
will resolve to
/usr/local/lib/tools.jar
and that is not a valid location.
To solve this, the $JAVA_HOME variable should instead point to this location /usr/local/java/jre (assuming the JDK path is /usr/local/java) -- there is actually jre folder inside the JDK installation directory, that comes with each JDK. This new setup will cause maven to look at the JRE directory, that is part of the JDK:
$JAVA_HOME\..\lib\tools
which now resolves to
/usr/local/java/jre/../lib/tools.jar
and finally to
/usr/local/java/lib/tools.jar
which is where the tools.jar really resides.
So, even if you are indeed using the JDK instead of the JRE, the $JAVA_HOME has to point to the JRE. Remember, the OS alternative should still refer to the JDK.
go to your jdk path where you installed your java
For e.g In my PC JDK installed in the following path
"C:\Program Files\Java\jdk1.7.0_17\";
After go to the lib folder e.g "C:\Program Files\Java\jdk1.7.0_17\lib"
in the lib directory there is tool.jar file
Copy this file and past it in the lib forlder of jre7 directory
for e.g
"C:\Program Files\Java\jre7\lib"
You may face similar problem on Ubuntu:
Embedded error: tools.jar not found: /usr/lib/jvm/java-7-openjdk-amd64/jre/../lib/tools.jar
The problem is with JAVA_HOME that is not set properly.
So, on Ubuntu 14.04 x64 using Java8:
sudo apt-get install openjdk-8-jdk openjdk-8-jre
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
As many people mentioned, it looks like you are looking in your JRE instead of the JDK for the tools.jar file.
I would also like to mention that on recent versions of the JDK, there is no more tools.jar file. I downloaded the most recent JDK as of today (JDK version 12) and I could not find any tools.jar. I had to download JDK version 8 (1.8.0) here https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html to get the tools.jar file. I downloaded that version, took the tools.jar file and put it into my recent version's lib folder.
It's worth observing that tools.jar has been removed from the JDK since Java 9. https://docs.oracle.com/javase/9/migrate/toc.htm#JSMIG-GUID-055EA9F4-835E-463F-B9E1-9081B3D9E55D
If people are facing this issue compiling a Java program with JDK 9+, you may need to review the dependencies of your projects.
In my case, I was trying to compile a project using AspectJ and the Maven plugin org.codehaus.mojo:aspectj-maven-plugin:1.11. After searching online, I found an alternative that supports Java 9+: dev.aspectj:aspectj-maven-plugin:1.13.M3.
I had the same problem even after installing Java JDK and set JAVA_HOME to ..\jdk1.6.0_45\bin folder.
Ant is still trying to find tools.jar in C:\Program Files\Java\jre6\lib folder.
I've fixed it by adding JAVACMD environment variable and set path for it to java.exe in the jdk folder.
In my case it was C:\Program Files\Java\jdk1.6.0_45\bin\java.exe
it has been solved with me in windows os by setting the JAVA_HOME variable before running as follows:
set JAVA_HOME=C:\Program Files\Java\jdk1.8.0_111
Make sure that both the %JAVA_HOME% and %JAVA_HOME%/bin paths are added to your PATH variable.
All the answers about copying tools.jar into the correct position is a poor idea at best.
Make sure that your IDE can find these jars the way it was designed and intended for.
In eclipse window> preferences>Java> Installed JRE, I pointed the directory to the jre directory in the jdk 1.7 and i worked file for me
e.g C:\Program Files\Java\jdk1.7.0_71\jre
I had my JDK_path (C:\Program Files\Java\jdk1.7.0_79) in my JAVA_HOME and also the JDK_path\bin in my PATH. But, still my ant was using the JRE instead of JDK.
The issue was I had C:\ProgramData\Oracle\Java\javapathbefore my JDK_path in PATH variable. I simply moved my JDK_path before the oracle one and the issue solved.
solving this problem I have simply copied the tools.jar file from C:\Program Files\Java\jre1.8.0_112\lib to C:\Program Files\Java\jdk1.8.0_112\lib so that I have two tools.jar files instead of one and problem disappeared.
Expected to find it in C:\Program Files\Java\jre6\lib\tools.jar
if you have installed jdk then
..Java/jdkx.x.x
folder must exist there so in stall it and give full path like
C:\Program Files\Java\jdk1.6.0\lib\tools.jar
Make sure that your classpath is set correctly and pointing to the correct version of the JDK that you have installed. Also, are you using Open JDK? I have had this issue before after I tried to move from open JDK to Suns JDK. This is an example of how that issue could be fixed.
maven-compiler-plugin use jdk ,not jre,
tools.jar is in C:\Program Files\Java\jdk1.6.0\lib\tools.jar
you must config project JRE System Libary with jdk,not jar. This is the simplest solution.
Right click on your ant file
Go to "Run as" then click on "Ant Build..."
Go to the "JRE" tab
Select a JDK and not a JRE
For me what's working: I downloaded an old version of Java 1.7
I actually set my JAVA_HOME from C:/program files X86/Java BUT after I installed the 1.7 version I had another Java in program files/Java. And at this moment I found the tools.jar here. Then I changed for this new path and it's working
I was also facing the same error.
This was removed after setting Java_Home path to C:\Program Files\Java\jdk1.8.0_121.
Please ensure bin is not included in the path and no slash is there after jdk1.8.0_121 after you have defined %JAVA_HOME%\bin in the system path variable.
If you're in a RHEL environment the package name containing tools.jar would end with "openjdk-devel".
This is the solution for Windows: in Computer > Advanced system settings > Advanced > Environment variables..., add this in System variables:
I have downloaded tools.jar and after that I copied it into path in error message.
C:\Program Files\Java\jdk-11.0.1\bin > paste here tools.jar
After that I have restarted Spring Tool Suit 4 and everything was working.
When I was trying to fix that problem I have made new environmental variable:
Control Panel / System / Advenced / Environmental variables / new
Name : JAVA_HOME
Value: C:\Program Files\Java\jdk-11.0.1
But I do not know is it necessary.
maybe you have updated the JREs in the OS, and the addition has added in the "path" of the environment variables an entry ".../Oracle/jer" that overwrites your JAVA_HOME.
try to remove it from the "path" by leaving JAVA_HOME.
I am trying to run a compiled java class and getting errors but when I checked my java environments it points to different version.
Javac –version gives me 1.8.0
And
Java –version gives me 1.6.2
The Java_home and path is pointing to the 1.8 version.
Please help.
Java installation under Windows is sometimes a really severe source of pain. The following assumes that you have Windows:
Check your path variable
Check JAVA_HOME variable
Newer versions of Java (1.6 ?, but 1.7 and 1.8) copy some Java executables into the System32 directory of the windows installation. Simply delete this files (or move them somewhere else for easy recovery)
running java applications by using .bat files a specific JDK / JRE can be provided.
There may be more sources of your problem. For example with Maven you depend on JAVA_HOME, with Eclipse you have the project settings, ...
Please check the following :
1) Check your path variable
2) Check JAVA_HOME variable
3)Delete the java,javaw and javaws .exe file from the system32 folder
java.exe while java installation gets copied under System32 directory. Also we tend to append java path in the end of the path variable. This causes running java command pointing to the one in System32 (it takes the first path value that is encountered and ignores rest, in this case java of system32 folder). And when it cannot find javac it looks to other values of path and finds it towards the end for the java JDK (this is the one you want to use).To overcome this problem give path to your JDK for example C:\ProgramData\Oracle\Java\bin as the first entry in the windows path variables. Even before your system32 entry. This ensures you point to only one java. My path entry looks something like this:-
%JAVA_HOME%\bin;%SystemRoot%\system32;
If you are running Windows, you could perhaps check the path environment variable. It might point to an older JRE installation.
One possibility is that your Java link is inconsistent. Go to this location (Windows):
C:\ProgramData\Oracle\Java\javapath and check where to does java.exe point.
In case it is not up-to-date consider fixing it with:
mklink /d C:\ProgramData\Oracle\Java\javapath "C:\Program Files\Java\<your JDK>\bin\"
(you may need to remove javapath old link before you create a new one)
I have multiple versions of Java installed in the environment(I know it is bad). I've set the JAVA_HOME to jdk 1_4 directory. This is not installed, but extracted from zip and placed it somewhere. We have java 1.8 JRE also installed in the system. I never set the path to this installed directory. Now i'm trying to run some ant script that depends on jdk 1_4. I get some exception saying that it is not able to find tools.jar in java1.8... .
My question is that when the path and java_home are set to jdk 14 why does the ant look for 1.8 version of java? I'm confused.
Update: I have looked up the duplicate issue.
Additional details: Java -version prints 1.8 with jdk 14 in the path and java_home. I uninstalled 1.8. reopened cmd tried java -version, now it errors out saying that it is not able to find java1.8 instead of trying to find the next java available in the path or java_home.
Error shown:
C:\Users\usrpao>java
Error: could not open `C:\Program Files\Java\jre8\lib\amd64\jvm.cfg'
I have multiple versions of Java installed in the environment(I know it is bad). I've set the JAVA_HOME to jdk 1_4 directory.
Not wrong at all. I have a similar setup because I have to switch between Java version.
First, install Java JDKs in the root of your drive. No spaces in the directory names. For example, C:\Java\Java-1.6-21 and C:\Java\Java-1.7-5.
In your Environment Variables section in your System Control Panel (under Advance), create an environment variable to point to each one of these Java Home directories. For example, JAVA_HOME_17 = C:\Java\Java-1.7.5 and JAVA_HOME_16 = C:\Java\Java-1.6-21. This should be a System Environment variable.
Create a JAVA_HOME environment variable that points to the Java version you want: JAVA_HOME = %JAVA_HOME_17%.
Now in the System PATH, prefix the PATH (the very first entry) with %JAVA_HOME%\bin.
When you open a console window, your default java and javac commands will be the correct Java version.
If you need to change a version, change the JAVA_HOME environment variable to point to the correct environment variable and open a new console window. Now that new Java will be in your path.
NOTE: It is vitally important that %JAVA_HOME%\bin is in the first part of your PATH before C:\Windows\System32. You don't want the java.exe that exists in that directory to be your default java.
You haven't specified the operating system, so:
on windows, java installs a java.exe in C:\Windows\system32, which is probably on the path before java_home, and so gets picked up
on Linux, various distributions that support multiple installed java versions will also have some symlink earlier on the path. Run 'which java' to determine where that symlink is
Multiple java versions in the system is the problem, I uninstalled all the java versions first. Restarted my machine. Path and java home points to the jdk 1.4. java -version now points to the version specified in the path. Thanks all.
When i am running Jenkins which checks out code from a repository and perform mvn package or some command. I get this error:
Unable to locate the Javac Compiler in: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/../lib/tools.jar
Please ensure you are using JDK 1.4 or above and not a JRE (the com.sun.tools.javac.Main class is required).
In most cases you can change the location of your Java installation by setting the JAVA_HOME environment variable.
My JAVA_HOME points at jdk location only.Still it looks at
/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/../lib/tools.jar
for the compiler.Why is that???
It seems the problem is with the code ..It points to /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/../lib/ for the tools.jar,whereas it needs to look into the /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/lib/ where the jar is present.I tried copying the jar to jre /lib/ but to no avail.Any solutions for this...
Thanks for d answers anyway..
You need jdk (java development kit) to compile java programs. jre only use to run compiled java programs. in your case its point to a jre and thats why you are getting this.
you can download the jdk and install.
you can download jdk rpm from here
http://www.oracle.com/technetwork/java/javase/downloads/jdk7u9-downloads-1859576.html
use this to choose java alternative if you have already installed.
/usr/sbin/alternatives --config java
Uninstall the installed JRE. Keep only one JAVA defined by JAVA_HOME and define your lib and classpath with respect to JAVA_HOME.