Installing Java 7 JDK
First, check whether Java 7 is already installed: You should expect output similar to the following, which lists a Java version that starts with If instead, you see a message containing: or you encounter this message then it is likely that you will need to install one of the latest Java 7 JDKs. You will need need to download and install either the Java 7 OpenJDK or Oracle's Java Development Kit (JDK) manually. Make sure you get JDK 7 and not 6; and the JDK (a Java package that includes a development kit as well as a runtime environment), not the JRE (runtime environment alone). Note: Depending on your system's access permissions, you may need root (e.g. To install the Java 7 OpenJDK, execute the following command: Check that it is properly installed with: You should now expect output similar to the following: To install Oracle's Java Development Kit (JDK), follow these instructions: Open a browser and go to To find out which distribution you have, 64-bit or 32-bit, at a Terminal (shell) command line, enter: A 64-bit system will report This should let you download the JDK. Run that file. (In the command below, the filename You can safely ignore any Under Ubuntu or other Debian Linux-based systems, if you encounter this error (or a similar error): See this comment for alternative download and installation instructions. Check that it is properly installed with: You should now expect output similar to the following: If after following the steps above, the reported version of Java is for some reason incorrect, you can manually correct this via your Linux 'alternatives' mechanism. This allows you to specify that several key Java commands, including the all-important (By convention, if you've installed Java by running the You can then choose to make the key and Check the Java version again by executing: You should now see output similar to the following: You can find more detailed instructions on installing Java under Linux at: http://www.oracle.com/technetwork/java/javase/index-137561.html#linuxjava -version
1.7.
(the "1.7" refers to Java 7):java version "1.7.0_13"
Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)
java version "1.6..."
(or anything else earlier than 1.7)java: command not found
sudo
) privileges to perform most or all of following actions.java -version
java version "1.7.0_13"
Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)
http://www.oracle.com/technetwork/java/javase/downloads/index.html
.linux
.rpm
(not .tar.gz
)x64
or i586
depending on whether your Linux distribution is 64-bit or 32-bit, respectively.uname -p
x86_64
, while a 32-bit system will report something like i386
, i486
, i586
, or i686
.jdk-7u13-linux-x64.rpm
is used as an example, representing the installer for Java 7 update 13, for 64-bit Linux systems. Please substitute the actual filename of the .rpm
file you downloaded.)rpm -Uvh jdk-7u13-linux-x64.rpm
Error: Could not open input file: {file_pathname}.pack
messages.The program 'rpm' is currently not installed.
java -version
java version "1.7.0_13"
Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)
java
and javac
commands, should always be run from your newly-installed copy of Java 7, instead of being run from some older version of Oracle's Java or from a version of OpenJDK, if either/both might also be installed on your system:update-alternatives --install /usr/bin/java java /usr/java/latest/bin/java 20000
update-alternatives --install /usr/bin/javac javac /usr/java/latest/bin/javac 20000
rpm
command, the path /usr/java/latest
should always point to the latest installation of Java on your system, according to one of Oracle's JDK RPM Installation for Linux installation guides. If that directory does not exist on your system, you should substitute the actual filesystem paths to your java
and javac
commands; for example, /usr/lib/jvm/jdk1.7.0_25/java
and /usr/lib/jvm/jdk1.7.0_25/javac
for an installation of Java 7, Update 25 in one recent installation on an Ubuntu system, wherever you see /usr/java/latest/bin/java
or /usr/java/latest/bin/javac
in the relevant commands, both above and below.)java
and javac
commands point to your newly-installed copy of Java 7, by:/usr/java/latest/bin/java
and /usr/java/latest/bin/javac
, respectively (or the actual filesystem paths to your java
and javac
commands):update-alternatives --config java
update-alternatives --config javac
java -version
java version "1.7.0_13"
Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)