java package bag with the guide

java package

A, java package used

1. Common package Introduction

• java.lang java core classes, to provide common functions, such as: String, Math, System and the like.
• java.util contains tools used, such as: definition of system properties, a set of frame-based interface, date.
• java.io class comprising a plurality of inputs and outputs.
• java.net classes and interfaces comprising performing operations associated with the network.
• jave.text contains some formatting related classes.
• java.sql JDBC database comprising programming for related classes and interfaces.
• java.awt contains building and managing the application image class interface (GUI), such as: Abstract Window Toolkit class (abstract window toolkits), etc.

2. Each package details

- CSDN original article

Second, build a package: package

1. The package statement

Package statement is the first statement java files, and at most one. The syntax is as follows:

package package name [package name.] [...] class name.;

 

2. Compile

Compile-time, it should be in the current directory of the parent directory in a package, such as: creating com.my.HelloWorld PACKAGE / Code directory, the compiler should be located at D:: in the D / Code position.

javac package name [\ package name] \ source files

 

3. Run

Run time, the directory location as described above.

java package name [. package name]. The main class

 

Third, the leader packet: import

 

Fourth, the basic data type classes that encapsulate

 

To be continued ...