I have javac complier installed on my mac mashine. By default its version is 7. I want to set complier version to 6 by default. How do I do it on Mac?
Ive found simular solution for ubuntu:
http://bartling.blogspot.com/2007/03/getting-java-6-to-be-default-jvm-on.html
$ export JAVA_HOME=/usr/libexec/java_home -v '1.6*'
Run a command which exports your configuration:
export JAVA_HOME=/usr/libexec/java_home -v '1.6*'
This would last only until you restart your computer, so be sure to include it to your configuration as well. I'm not an OSX user so I'm not sure how exactly is the file called, but it's basically and equivalent of ".bashrc" on Linux. Just put the export line on the end of the file, so it will export it every time in future. (It's probably the same file because they're both UNIX based)
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 need to uninstall Java jdk1.6.0.27 from RHEL 5.7 and then install another version jre-7u40-linux-x64.rpm.
The firs thing I did was to find out the current java version installed using the
java -version command and the output is "java version "1.6.0_27"".
After that I tried to check the previews version of java with the command:
rpm -qi jdk
The output is "package jdk is not installed"
After installing the package jre-7u40-linux-x64.rpm in the /usr/java directory there are two java packages.
The output of the ls command on /usr/java is:
default jdk1.6.0_27 jre1.7.0_40 jre-7u40-linux-x64.rpm latest.
when I run the command "alternatives --config java" the output is:
*+ 1 /usr/java/latest/bin/java
I am new to RHEL and I need some help to understand the situation.
To conclude I need some help to remove the previews jdk1.6.0.27 and to install jre1.7.0_40.
Thank you in advance for your help!
Best regards,
Claudio
First, find out your real java executable. Start with
which java
This is going to give you some response such as:
/usr/bin/java
Next, do
ls -l /usr/bin/java
(Or whatever it returned).
It will probably write something like:
/usr/bin/java -> /etc/alternatives/java
Do the same for whatever is pointed to by the arrow, until finally, when you do ls -l on it, there is no arrow.
Then, for that particular file, find out which rpm provides it by using
rpm -q -f <full path of the file you found>
It should tell you which package it belongs to, and then you can uninstall that.
However, if the rpm command returns The file ... is not owned by..., then your Java has not been installed using an rpm. It may have been installed manually by someone in the past.
This makes uninstalling it a lot more problematic.
If you haven't found your answer:
leave old java where it is, don't even bother with it
install new version with: rpm -ivh /root/jdk-7u40-linux-x64.rpm
deactivate old java
export new version
Deactivating old java (note entering hashtags before every line, manual installation required editing of profile, so edit it one more):
vi /etc/profile
#JAVA_HOME=/usr/java/jdk1.6.0_27
#export JAVA_HOME
#PATH=$JAVA_HOME/bin:$PATH
#export PATH
Exporting nev version (note adding new lines in profile followed after old entries):
export JAVA_HOME=/usr/java/latest
export JRE_HOME=$JAVA_HOME/jre
export J2RE_HOME=$JAVA_HOME/jre
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$J2RE_HOME/bin:$PATH
Check nev version with standard command for checking of installed sw.
Hope this suits your needs.
Just wondering: you're trying to prepare BFBOX for acceptance? Just courious! If you want more info please send me an email, ok?
I followed "http://codesfusion.blogspot.com/2013/10/setup-hadoop-2x-220-on-ubuntu.html" to install hadoop on ubuntu. But, upon checking the hadoop version I get the following error:
Error: Could not find or load main class
org.apache.hadoop.util.VersionInfo
Also, when I try: hdfs namenode -format
I get the following error:
Error: Could not find or load main class
org.apache.hadoop.hdfs.server.namenode.NameNode
The java version used is:
java version "1.7.0_25"
OpenJDK Runtime Environment (IcedTea 2.3.10) (7u25-2.3.10-1ubuntu0.12.04.2)
OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)
It is a problem of environmental variables setup. Apparently, I didnt find one which can work until NOW. I was trying on 2.6.4. Here is what we should do
export HADOOP_HOME=/home/centos/HADOOP/hadoop-2.6.4
export HADOOP_INSTALL=$HADOOP_HOME
export HADOOP_MAPRED_HOME=$HADOOP_HOME
export HADOOP_COMMON_HOME=$HADOOP_HOME
export HADOOP_HDFS_HOME=$HADOOP_HOME
export YARN_HOME=$HADOOP_HOME
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
export PATH=$PATH:$HADOOP_HOME/sbin:$HADOOP_HOME/bin
export HADOOP_CONF_DIR=$HADOOP_HOME
export HADOOP_PREFIX=$HADOOP_HOME
export HADOOP_LIBEXEC_DIR=$HADOOP_HOME/libexec
export JAVA_LIBRARY_PATH=$HADOOP_HOME/lib/native:$JAVA_LIBRARY_PATH
export HADOOP_CONF_DIR=$HADOOP_PREFIX/etc/hadoop
Add these into your .bashrc and dont forget to do
source ~/.bashrc
I think your problem will be solved as was mine.
You probably did not follow the instructions correctly. Here are some things to try and help us / you diagnose this:
In the shell that you ran hadoop version, run export and show us the list of relevant environment variables.
Show us what you put in the /usr/local/hadoop/etc/hadoop/hadoop-env.sh file.
If neither of the above gives you / us any clues, then find and use a text editor to (temporarily) modify the hadoop wrapper shell script. Add the line "set -xv" somewhere near the beginning. Then run hadoop version, and show us what it produces.
Adding this line to ~/.bash_profile worked for me.
export HADOOP_PREFIX=/<where ever you install hadoop>/hadoop
So just:
$ sudo open ~/.bash_profile then add the aforesaid line
$ source ~/.bash_profile
Hope this helps (:
I was facing the same issue. Although it may seem so simple but took away 2 hrs of my time. I tried all the things above but it didn't help.
I just exit the shell i was in and tried again by logging into the system again. Then things worked!
Try to check:
JAVA_HOME, all PATH related variables in Hadoop config
run: . ~/.bashrc (note the dot in front) to make those variables available in your environment. It seems that the guide does not mention this.
I got the same problem with hadoop 2.7.2
after I applied the trick shown I was able to start hdfs but later I discovered that the tar archivie I was using was missing some important pieces. So downloading the 2.7.3 everything worked as it is supposed to work.
My first suggestion is to download again the tar.gz at the same version or major.
If you are continuing to reading... this how I solved the problem...
After a fresh install hadoop was not able to find the jars.
I did this small trick:
I located where the jars are
I did a symbolic link of the folder to
$HADOOP_HOME/share/hadoop/common
ln -s $HADOOP_HOME/share/hadoop/kms/tomcat/webapps/kms/WEB-INF/lib $HADOOP_HOME/share/hadoop/common
for version command you need hadoop-common-2.7.2.jar, this helped me to find where the jars where stored.
After that...
$ bin/hadoop version
Hadoop 2.7.2
Subversion https://git-wip-us.apache.org/repos/asf/hadoop.git -r b165c4fe8a74265c792ce23f546c64604acf0e41
Compiled by jenkins on 2016-01-26T00:08Z
Compiled with protoc 2.5.0
From source with checksum d0fda26633fa762bff87ec759ebe689c
This command was run using /opt/hadoop-2.7.2/share/hadoop/kms/tomcat/webapps/kms/WEB-INF/lib/hadoop-common-2.7.2.jar
Of course any hadoop / hdfs command works now.
I'm again an happy man, I know this is not a polite solution but works at least for me.
I got that error , I fixed that by editing ~/.bashrc
as follow
export HADOOP_HOME=/usr/local/hadoop
export PATH=$HADOOP_HOME/bin:$PATH
then open terminal and write this command
source ~/.bashrc
then check
hadoop version
Here is how it works for Windows 10 Git Bash (mingw64):
export HADOOP_HOME="/PATH-TO/hadoop-3.3.0"
export PATH=$PATH:$HADOOP_HOME/sbin:$HADOOP_HOME/bin
export HADOOP_CLASSPATH=$(cygpath -pw $(hadoop classpath)):$HADOOP_CLASSPATH
hadoop version
copied slf4j-api-1.6.1.jar into hadoop-3.3.0\share\hadoop\common
I added the environment variables described above but still didn't work. Setting the HADOOP_CLASSPATH as follows in my ~/.bashrc worked for me:
export HADOOP_CLASSPATH=$(hadoop classpath):$HADOOP_CLASSPATH
I used
export PATH=$HADOOP_HOME/bin:$PATH
Instead of
export PATH=$PATH:$HADOOP_HOME/bin
Then it worked for me!
I have installed Java 1.7.0_45 on Mac OS X 10.6.8 using Pacifist [http://www.charlessoft.com/] however I am unable to run a jar file which I have downloaded. The jar file is a threaded application.
The error message I am getting is:
java -jar context.jar
2013-10-31 14:14:41.898 java[330:a07] *** NSInvocation: warning: object 0x109356390 of class 'ThreadUtilities' does not implement methodSignatureForSelector: -- trouble ahead
2013-10-31 14:14:41.900 java[330:a07] *** NSInvocation: warning: object 0x109356390 of class 'ThreadUtilities' does not implement doesNotRecognizeSelector: -- abort
Trace/BPT trap
Is there anyway I can run the jar. I have set the JAVA_HOME path properly and java -version is showing 1.7.0_45 as the version.
The same application works properly on Windows Java 1.7.0_45 and also on Linux Java 1.7.
The web search for the solution and the given keywords return very few results and none of them have any specific solution in it. I am new to mac so I am not fully able to understand the issue.
Alternatively, is there anyway I can run Java from folder in Mac like I can do in windows and Linux by just extracting the Java contents and changing the JAVA_HOME. If that is possible then I should be able to run my JAR.
I had kind of same problem while installing an application through jar file, my Java was not detected by the jar application installer,
Over here I see that one of the method is not accessible, could be a same problem. But I am not very sure of it.
make sure you have rt.jar in your JAVA_HOME/jre/lib/ folder
In case you don't have then you are required to have it through the process of creation of symbolic link.
In the command below replace your_java_version with proper version matching your requirement.
sudo mkdir -p /System/Library/Frameworks/JavaVM.framework/Versions/<your_java_version>/Home/jre/lib
Go into the directory:
cd /System/Library/Frameworks/JavaVM.framework/Versions/<your_java_version>/Home/jre/lib/
Create symbolic link :
sudo ln -s ../../../Classes/classes.jar rt.jar
Hope this solves your problem.
I get the exact same problem with MacOS 10.6.8 and JDK 7. In order to run the jar I had to use the System JRE which is 1.6.x (In my case I wanted to install Squirrel
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -jar >squirrel-sql-3.6-MACOSX-install.jar
Many Java applications that use shell scripts to configure their environment use the JAVA_HOME environment variable to start the correct version of Java, locate JRE JARs, and so on.
In macOS X 10.6, the following paths seem to be valid for this variable
/Library/Java/Home
/System/Library/Frameworks/JavaVM.framework/Home
/System/Library/Frameworks/JavaVM.framework/Versions/Current
Some of these are symlinks to the actual current VM (as defined in the Java Preference pane).
But which one should be used—or is it okay to use any of them?
I just set JAVA_HOME to the output of that command, which should give you the Java path specified in your Java preferences. Here's a snippet from my .bashrc file, which sets this variable:
export JAVA_HOME=$(/usr/libexec/java_home)
I haven't experienced any problems with that technique.
Occasionally I do have to change the value of JAVA_HOME to an earlier version of Java. For example, one program I'm maintaining requires 32-bit Java 5 on OS X, so when using that program, I set JAVA_HOME by running:
export JAVA_HOME=$(/usr/libexec/java_home -v 1.5)
For those of you who don't have java_home in your path add it like this.
sudo ln -s /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java_home /usr/libexec/java_home
References:
Oracle explains the java_home command
An article for configuring the JDK in Spring Tool Suite (Eclipse
2019) on MacOS
Also, it`s interesting to set your PATH to reflect the JDK. After adding JAVA_HOME (which can be done with the example cited by 'mipadi'):
export JAVA_HOME=$(/usr/libexec/java_home)
Add also in ~/.profile:
export PATH=${JAVA_HOME}/bin:$PATH
P.S.: For OSX, I generally use .profile in the HOME dir instead of .bashrc
I am having MAC OS X(Sierra) 10.12.2.
I set JAVA_HOME to work on React Native(for Android apps) by following the following steps.
Open Terminal (Command+R, type Terminal, Hit ENTER).
Add the following lines to ~/.bash_profile.
export JAVA_HOME=$(/usr/libexec/java_home)
Now run the following command.
source ~/.bash_profile
You can check the exact value of JAVA_HOME by typing the following command.
echo $JAVA_HOME
The value(output) returned will be something like below.
/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home
That's it.
I'm on Mac OS 10.6.8
The easiest solution works for me is simply put in
$ export JAVA_HOME=$(/usr/libexec/java_home)
To test whether it works, put in
$ echo $JAVA_HOME
it shows
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
you can also test
$ which java
Nowadays Java seems to be installed in /Library/Java/JavaVirtualMachines
I tend to use /Library/Java/Home. The way the preferences pane works this should be up to date with your preferred version.
That above works not any more in YOSEMITE for GRAPHICAL APPLICATIONS! Like eclipse, or anything started with Spotlight. (.bash_profile, launchd.conf works for terminal sessions only.)
Before starting eclipse, just open a terminal window, and give out the following command:
launchctl setenv JAVA_HOME /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home
(With your installation path! Perhaps works with $(/usr/libexec/java_home) instead of the full path too.)
View the whole excellent article about the permanent solution here:
Setting environment variables via launchd.conf no longer works in OS X Yosemite/El Capitan/macOS Sierra?
It is recommended to check default terminal shell before set JAVA_HOME environment variable, via following commands:
$ echo $SHELL
/bin/bash
If your default terminal is /bin/bash (Bash), then you should use #hygull method
If your default terminal is /bin/zsh (Z Shell), then you should set these environment variable in ~/.zshenv file with following contents:
export JAVA_HOME="$(/usr/libexec/java_home)"
Similarly, any other terminal type not mentioned above, you should set environment variable in its respective terminal env file.
This method tested working in macOS Mojave Version 10.14.6.
I've found this stack to help, i was having the same issue and i could fix:
My java path was here:
/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home
and was needed to put into my .bash_profile:
export JAVA_HOME=\"/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home\"
Hope help
As other answers note, the correct way to find the Java home directory is to use /usr/libexec/java_home.
The official documentation for this is in Apple's Technical Q&A QA1170: Important Java Directories on OS X: https://developer.apple.com/library/mac/qa/qa1170/_index.html
For me maven seems to work off the .mavenrc file:
echo "export JAVA_HOME=$(/usr/libexec/java_home -v 1.8)" > ~/.mavenrc
I'm sure I picked it up on SO too, just can't remember where.
Create file ~/.mavenrc
then paste this into the file
export JAVA_HOME=$(/usr/libexec/java_home)
test
mvn -v
Skipping Terminal setup since you mentioned applications, permanent system environment variable set up (works for macOS Sierra; should work for El Capitan too):
launchctl setenv JAVA_HOME $(/usr/libexec/java_home -v 1.8)
(this will set JAVA_HOME to the latest 1.8 JDK, chances are you have gone through serveral updates e.g. javac 1.8.0_101, javac 1.8.0_131)
Of course, change 1.8 to 1.7 or 1.6 (really?) to suit your need and your system
For Fish Shell users, use something like the following: alias java7 "set -gx JAVA_HOME (/usr/libexec/java_home -v1.7)"