Basic Java knowledge (1), Basic java knowledge

Basic Java knowledge (1), Basic java knowledge

The Department has received a new project. The background uses the Java framework play framework. The frontend is html, and the frontend and backend interacts with each other through rest to support the multi-end Internet architecture.

Because there was no Java Foundation and few front-end applications, I decided to take a deeper look at Java web development. This series mainly records my learning process and problems.

References: http://www.weixueyuan.net/java/rumen/

 

Environment Configuration:

JDK 1.7

: Http://www.oracle.com/technetwork/java/javase/downloads/index.html

Installation configuration: http://jingyan.baidu.com/article/ed15cb1b2ed02a1be369818a.html

 

Development Tool Eclipse

: Http://www.eclipse.org/downloads/

 

 

Environment configuration Tutorial: http://www.weixueyuan.net/java/rumen/

 

 

The first Java sample program

Http://www.weixueyuan.net/view/5947.html

public class HelloWorld {    public static void main(String[] args){        System.out.println("Hello World!");    }}

 

 

Java API instructions

Http://www.oracle.com/technetwork/java/api/index.html

 

Several frequently-used java packages:

Java. lang	This package provides basic classes for Java programming, such as Object, Math, String, StringBuffer, System, Thread, etc.
Java. util	The package provides collection frameworks, legacy collection classes, event models, date and time implementations, internationalization, and a variety of Utility Classes (string tag generator, random number generator, and Bit Array ).
Java. io	The package provides system input and output through the file system, data stream, and serialization.
Java.net	This package provides classes for network application and development.
Java. SQL	This package provides APIs for accessing and processing data stored in a data source (usually a relational database) using the Java language.
..	..

 

 

 

 

 

 

 

 

 

If you want to use classes in the Java package, you must first use the import Statement for import.

 

 

 

The overview section ends. Next we will start to learn the basic Java syntax.