What is java?
A high-level programming language developed by Sun Microsystems. Java was originally called OAK, and was designed for handheld devices and set-top boxes. Oak was unsuccessful so in 1995 Sun changed the name to Java and modified the language to take advantage of the burgeoning World Wide Web.
Java is an object-oriented language similar to C++, but simplified to eliminate language features that cause common programming errors. Java source code files (files with a .java extension) are compiled into a format called bytecode (files with a .class extension), which can then be executed by a Java interpreter. Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (VMs), exist for most operating systems, including UNIX, the Macintosh OS, and Windows. Bytecode can also be converted directly into machine language instructions by a just-in-time compiler (JIT).
Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web. Small Java applications are called Java applets and can be downloaded from a Web server and run on your computer by a Java-compatible Web browser, such as Netscape Navigator or Microsoft
root@hari:/usr/local/java# wget http://uni-smr.ac.ru/archive/dev/java/SDKs/sun/j2se/7/jdk-7u45-linux-i586.tar.gz logstash@hari:~$ vi .bash_profile export PATH="/usr/local/java/jdk1.7.0_45/bin:$PATH" logstash@hari:~$ java -version java version "1.7.0_45" Java(TM) SE Runtime Environment (build 1.7.0_45-b18) Java HotSpot(TM) Client VM (build 24.45-b08, mixed mode)
Java download link for openjdk6 and jdk7
We can install java in ubuntu with the below command.
#apt-get install openjdk-7-jdk