Java is a high-level programming language launched by Sun Microsystems in May 1995. Java can run on multiple platforms, such as Windows, Mac OS, and other systems of various UNIX versions.
The three platforms of Java
Java Platform, Standard Edition (Java SE: Java Platform Standard Edition)
is a solution for developing common desktop and business applications
This technical system is the basis of the other two, and can complete the development of some desktop applications
Java Platform, Micro Edition (Java ME: Java Platform Micro Edition)
is a solution for the development of electronic consumer products and embedded devices
Java Platform, Enterprise Edition (Java EE: Java Platform Enterprise Edition)
It is a set of solutions for developing applications in an enterprise environment
The technologies included in the technical system, such as Servlet, Jsp, etc., are mainly aimed at the development of Web applications.
Java is a cross-platform language that can run on different operating systems by installing a JVM virtual machine. To execute a Java application, a Java Runtime Environment (JRE) must be installed.
JRE (Java Runtime Environment Java Runtime Environment)
It includes the Java Virtual Machine (JVM Java Virtual Machine) and the core class libraries required by the Java program. If you want to run a developed Java program, you only need to install the JRE in the computer.
JDK (Java Development Kit Java Development Kit)
JDK is provided to Java developers, which includes Java development tools and JRE. So after installing the JDK, there is no need to install the JRE separately.
Among them, the development tools: compilation tools (javac.exe) packaging tools (jar.exe), etc.
Java version history (from Wikipedia)
On May 23, 1995, the Java language was born
In January 1996, the first JDK-JDK1.0 was born
In April 1996, 10 major operating system vendors declared that they would embed JAVA technology in their products
In September 1996, about 83,000 web pages were created using JAVA technology.
On February 18, 1997, JDK1.1 was released
On April 2, 1997, the JavaOne conference was held, with more than 10,000 participants, setting a record for the scale of similar conferences in the world at that time
In September 1997, JavaDeveloperConnection community members exceeded 100,000
In February 1998, JDK1.1 was downloaded more than 2,000,000 times
On December 8, 1998, the JAVA2 enterprise platform J2EE was released
In June 1999, Sun released three versions of Java: Standard Edition (J2SE), Enterprise Edition (J2EE) and Micro Edition (J2ME)
On May 8, 2000, JDK1.3 was released
On May 29, 2000, JDK1.4 was released
On June 5, 2001, NOKIA announced that it would sell 100 million Java-enabled mobile phones by 2003
On September 24, 2001, J2EE 1.3 was released
On February 26, 2002, J2SE1.4 was released, and the computing power of Java has been greatly improved since then.
At 18:00PM on September 30, 2004, J2SE1.5 was released, becoming another milestone in the history of Java language development. To express the importance of this release, J2SE 1.5 was renamed Java SE 5.0
In June 2005, the JavaOne conference was held, and SUN released Java SE 6. At this point, various versions of Java have been renamed to remove the number "2" in them: J2EE was renamed Java EE, J2SE was renamed Java SE, and J2ME was renamed Java ME
In December 2006, Sun released JRE6.0
In December 2009, Sun released Java EE 6
In November 2010, Apache threatened to withdraw from the JCP due to Oracle's unkindness to the Java community
On July 28, 2011, Oracle Corporation released Java SE 7
On March 18, 2014, Oracle Corporation released Java SE 8
On September 21, 2017, Oracle Corporation released Java SE 9
On March 21, 2018, Oracle Corporation released Java SE 10
Java resources
JDK installation
http://www.oracle.com/technetwork/java/javase/downloads/index.html
Installation of Java development tools
Development tools, Eclipse IDE for Java Developers
Develop your first applet with Eclipse.
A workspace needs to be specified.
Create a new project.
Create a new package.
Create a new class.
The main program can be written in the class file.