Apache Ant installation Windows 7 - java

When I do ant -version on command line, it says not recognized. Any ideas on how to fix? I'm trying to make a build.xml for a Java project.

You have set JAVA_HOME and ANT_HOME as User environment variable. The path you set is in System environment variable.
You can fix it by many ways. One way will be to define JAVA_HOME and ANT_HOME in System Environment setting.
Another way will be to modify PATH variable in user environment section.

Make sure your JAVA_HOME and ANT_HOME and PATH are set correctly.
ANT_HOME is used by the launcher script for finding the libraries.
JAVA_HOME is used by the launcher for finding the JDK/JRE to use. (JDK is recommended as some tasks require the java tools.) If not set, the launcher tries to find one via the %PATH% environment variable.
PATH is set for user convenience. With that set you can just start ant instead of always typing the/complete/path/to/your/ant/installation/bin/ant.
Set these variables correctly and open a new cmd window (don't use old cmd window, please open new window)
type echo %PATH% , should show java and ant
Open command window(cmd) and type
java -version
If this shows java version , this means java is in your path and working.
finally type ant -version

Related

Windows environment variable resolution error

I am trying to put the JAVA JDK path into the Windows PATH environment variable.
I changed/inserted the appropriate variables and got the command javac to be working yesterday, but when I tried the same thing today, I am getting the command not recognized error.
Here are the values of the relevant variables (on a fresh cmd instance):
>> echo %JAVA_HOME%
JAVA_HOME=C:\Program Files\Java\jdk1.8.0_101
>> echo %PATH%
C:\windows\system32;C:\windows;C:\windows\System32\Wbem;C:\windows\System32\WindowsPowerShell\v1.0\;%JAVA_HOME%\bin;C:\Users\anmol\AppData\Local\Programs\Python\Python35\Scripts\;C:\Users\anmol\AppData\Local\Programs\Python\Python35\;C:\Users\anmol\AppData\Local\Programs\Python\Launcher\
I tried to avoid the spaces present in 'Program Files' by writing JAVA_HOME=C:\Progra~1\Java\jdk1.8.0_101, but the error persisted.
Also, if I open a cmd and type set path=%JAVA_HOME%\bin;%path% and then in the same session type javac, it is recognized correctly.
Can anyone tell what is going on and how to set the PATH correctly?
You have modified PATH with the set command, which applies the changes to the current terminal. To make it a persistent system wide setting, use setx instead.
You'll need both, PATH and JAVA_HOME in the system environment.
Note that ` does not modify the current terminal's environment settings:
NOTE: 1) SETX writes variables to the master environment in the registry.
2) On a local system, variables created or modified by this tool
will be available in future command windows but not in the
current CMD.exe command window.
What has happened in your case? You have set the PATH environment variable at a time where JAVA_HOME was not known yet. In that case, %JAVA_HOME% becomes part of PATH literally. The following example demonstrates that:
C:\>set X=%A%
C:\>set A=something
C:\>set X
X=%A%
C:\>set B=something
C:\>set X=%B%
C:\>set X
X=something
To fix it, set JAVA_HOME using setx, close the terminal and open a new one. Then use setx to set PATH, close the terminal and open a new one.
or
set JAVA_HOME using setx, set JAVA_HOME using set to update the console. Then use setx to set PATH, close the terminal and open a new one.

Java: System cannot find the file C:\ ... java.exe

I have installed Java 8 and set my JAVA_HOME and JRE_HOME paths and added %JAVA_HOME% to the start of the path variable.
I created a helloworld.java application and am able to compile it using:
javac helloworld.java
However, when I try to run:
java helloworld
I get the error:
The system cannot find the file C:\ProgramData\Oracle\Java\javapath\java.exe
How can I solve this?
1.Just go to C:\ProgramData\Oracle\Java\javapath\
2.You will find there shortcuts for java.exe,javaw.exe,javaws.exe which are pointing to a location where they actually are not existing now
3.Go to the jre location where you have installed java like C:\Program Files\Java\jre6\bin
You will find java.exe,javaw.exe,javaws.exe
Create shortcuts for these files and replace with the ones which are present in C:\ProgramData\Oracle\Java\javapath.
It works
Just set %JAVA_HOME%/bin to your path variable.
If you are blocked from modifying system variables from command line, but are able to open up an elevated command prompt, then run a command like this:
setx \M JAVA_HOME "C:\Program Files\Java\jdk1.8.0_25"
But of course, change the directory to point to your installed version of java. Note that the JAVA_HOME path does not point into the bin directory, it stops one level above bin.
I was able to solve this issue. To do so I used the advice from this answer:
Java SE Development Kit 8u25 on a 64-bit Windows 8
Set the following user environment variables (== environment variables of type user variables)
•JAVA_HOME : C:\Program Files\Java\jdk1.8.0_25
•JDK_HOME : %JAVA_HOME%
•JRE_HOME : %JAVA_HOME%\jre
•CLASSPATH : .;%JAVA_HOME%\lib;%JAVA_HOME%\jre\lib
•PATH : your-unique-entries;%JAVA_HOME%\bin
(make sure that the longish your-unique-entries does not contain any other references to another Java installation folder.)

JAVA_HOME is not recognized as an internal/external command

I've tried just about everything but it will not recognize it.
I have the latest version of JDK installed, the path is located at "C:\Program Files\Java\jdk1.8.0_25". This is what I'm using for my "variable value" field when I add the new variable "JAVA_HOME"..
I also have a %JAVA_HOME%\bin; in my path variable. I've restarted multiple times, making small changes..
Help me :(
Keep in mind I don't have much of a clue of what I'm doing.. So I could be going about it completely wrong.. Running it in cmd
Change the path value %JAVA_HOME%\bin, instead of set this
C:\Program Files\Java\jdk1.8.0_25\bin
After setting that, open command prompt and check whether you have set JAVA_HOME correctly.
echo %JAVA_HOME%
java
echo %JAVA_HOME% will print the location where java installed and java will show the usage of java.
See here how to set JAVA_HOME

Why I do not need to set CLASSPATH and JAVA_HOME in Mac OS X?

I am using jdk 1.7, after Installation I did not set JAVA_HOME or CLASSPATH environment variable, and I use it to compile a servlet class and everything worked fine.
So I want to known, why I am not supposed to set these Environment variables ? Can JDK auto resolve CLASSPATH ?
JAVA_HOME is used by some tools (Ant, Maven, etc.), but is not needed by Java (or javac) itself.
CLASSPATH should never be used. It sets a global classpath that is supposed to be common to several Java programs installed on your computer, which is completely unrealistic. Every program should have its own classpath passed as argument to the command using the -classpath option.
And that's true on all the platforms.
Most of the Unixes and Mac use the so-called Bash Shell in the "Terminal". When you launch an executable program (with file permission of executable) in a Bash shell, the system searches the program in ALL the directories listed in the PATH.
The have JAVA_HOME path and can be set as:
setenv JAVA_HOME /System/Library/Frameworks/JavaVM.framework/Home
To setup JAVA_HOME:
$ vi ~/.bash_profile
export JAVA_HOME=$(/usr/libexec/java_home)
$ source ~/.bash_profile
$ echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/jdk-11.0.1.jdk/Contents/Home

javac not recognized

What can I do when I keep receiving the error
'javac' is not recognized as an internal or external command, operable program or batch file
when I want to compile my jar or .class file?
Thanks
Make sure %JAVA_HOME%/bin is on your %PATH% (or $JAVA_HOME on the $PATH in *nix).
It means that it is not in your path. You have the following options:
1) Change to the directory where javac lives before calling it.
2) Use the full path to javac when making the call, e.g. C:\java\jdk1.6.0_12\bin\javac ...
3) Add the javac directory to the PATH environment variable
This just means that javac isn't in your PATH variable.
On Windows, you just have to add the folder that contains javac.exe to the PATH environment variable (Win+Pause/Break).
On Linux/Mac/Unix, just append that directory to $PATH in .bashrc or similar.
The error that you are seeing is generated by Windows, and isn't specific to Java. That error means that you typed a command and Windows could not find the command by that name.
The easiest way of rectifying the situation is to ensure that Java is properly installed in your system's PATH.
First, ensure that you have a JDK installed (and not just a JRE). Your next best bet is to add an environment variable called JAVA_HOME and point it at the base install directory for the version of Java that you installed.
Next, modify your PATH environment variable by prepending the string %JAVA_HOME%\bin; to whatever is already in your PATH. If you look at the contents of that directory, you will see that javac is in there (along with a number of other Java development tools).
You have to install JDK (which includes javac compiler) and ensure that it's in the path. See http://java.sun.com/javase/downloads/index.jsp
Common Error Messages from SUN Tutorial page
Step 4 (Update the PATH variable) of the JDK installation instructions explains what you should do to make it so that you can just type javac in the command prompt window.
The link below gives a step by step explanation on how to set up java_home and path variables.
JAVA_HOME setup
Even if I had
JDK installed
JAVA_HOME defined
%JAVA_HOME%\bin present in my %PATH%
I still had this error. I resolved it by eliminating the JRE from my path variable. It was put before JAVA_HOME, has no javac. It seems Windows can't find javac in JAVA_HOME\bin in this case.
For Windows
Control Panel > System...Then click Advanced System Setting (left pane)...then popup window will open...then click Environment Variables...Then another window will open...click New and add enter information below
Variable name: PATH
Variable value: C:\Program Files\Java\jdk1.7.0_45\bin [*make sure this is the right path for you]
Then it should work
Check whether you have JDK installed; if not installed, Install
If JDK is installed, navigate into the bin folder of the installation, and try to execute javac.
If javac executes, proceed (+:
If javac does not execute, check your system path, and java path, and return to 2 above!

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