JDK-supported character sets and system attribute values

System attribute values and character sets are often used in Java development. Frequent queries are really unpleasant. you have to write a code to check it out. Paste it out and it will be easy to use later.

Obtain the character set supported by the current JDK

Public static void getJDKEncoding () {SortedMap <String, Charset> map = Charset. availableCharsets (); for (String alias: map. keySet () {System. out. println ("alias:" + alias + "\ t Character Set object:" + map. get (alias ));}}

Alias: alias	Character Set object: Charset
Big5	Big5
GBK	GBK
UTF-8	UTF-8
ISO-8859-1 ......	ISO-8859-1 .....

A total of 167 types are supported.

Obtains information about the current system.

/*** Get the current System environment information */public static void getSystemProperties () {Properties p = System. getProperties (); for (Object key: p. keySet () {System. out. println ("name:" + key + "\ tvalue:" + p. get (key ));}}

Key: attribute name	Value: Attribute Value	Description
Java. runtime. name	Java (TM) SE Runtime Environment
Sun. boot. library. path	C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ bin
Java. vm. version	23.25-b01	Java Virtual Machine version
Java. vendor. url	Http://java.oracle.com/	Provider URL
Path. separator	;	The system path delimiter for Linux is ":", which has been planted.
Java. vm. name	Java HotSpot (TM) Client VM	Java Virtual Machine name; among other Java virtual machines, Sun Classic/ExactVM, the world's first commercial Java Virtual Machine), IBMJ9, etc.
Sun. jnu. encoding	GBK	File Name Encoding
Java. runtime. version	1.7.0 _ 25-b17
Java. library. path	Values in system environment variables
File. separator	\	File directory delimiter in Windows) Linux /)
File. encoding	UTF-8	File Content Encoding
Sun. boot. class. path	C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ resources. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ rt. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ sunrsasign. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ jsse. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ jce. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ charsets. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ lib \ jfr. jar; C: \ Program Files \ Java \ jdk1.7.0 _ 25 \ jre \ classes
Sun. java. launcher	SUN_STANDARD
Java. vm. specification. name	Java Virtual Machine Specification
Java. vm. specification. vendor	Oracle Corporation	Provider
Java. specification. name	Java Platform API Specification	Specification
Sun. management. compiler	HotSpot Client Compiler
Java. class. version	51.0	Important: major. minor; Class file version number
Line. separator	\ R	Windows (\ r) Liunx (\ n) The above code is hard to display. You can view the result through debugging: 650) this. length = 650; "src =" http://www.bkjia.com/uploads/allimg/131228/112H02c0-0.png "title =" qqpinyin unnamed .png "data-pinit =" registered "width =" 200 "height =" 60 "border =" 0 "hspace =" 0 "vspace = ""0" style = "width: 200px; height: 60px; "/>
Java. io. tmpdir	C: \ Users \ ZHANGX ~ 1 \ AppData \ Local \ Temp \	Temporary directory You can set: java -Djava.io.tmpdir=/path/to/tmpdir
Java. awt. printerjob	Sun. awt. windows. WPrinterJob
Sun. arch. data. model	32	JDK and JRE have nothing to do with the number of bits)
Sun. cpu. endian	Little	Small-end Mode
Sun. desktop	Windows

The following is a user-level information:

Key: attribute name	Value: Attribute Value	Description
User. country	CN	Country
User. dir	E: \ workspace _ jsmart \ Andvance	Working directory
OS. arch	X86	System attributes of JRE are independent of the number of digits of the operating system)
OS. name	Windows 7	Operating System
OS. version	6.1	Operating system version
User. home	C: \ Users \ Zhang	User directory
User. timezone		User's Time Zone
User. name	Zhang	Username of the current logon System
User. language	Zh	Language, corresponding to country information, which can be found in the language of the browser Internet option)

The value of "OS. arch" has nothing to do with the number of digits of the operating system. It depends on the number of JRE digits installed on the machine. See:

Bytes.

See an article:

Java's "OS. arch" System Property is the Bitness of the JRE, NOT the Operating System

Bytes.

import com.sun.servicetag.SystemEnvironment;public class OSArchLies {                                            public static void main(String[] args) {                                                // Will say "x86" even on a 64-bit machine    // using a 32-bit Java runtime    SystemEnvironment env =        SystemEnvironment.getSystemEnvironment();    final String envArch = env.getOsArchitecture();                                                // The os.arch property will also say "x86" on a    // 64-bit machine using a 32-bit runtime    final String propArch = System.getProperty("os.arch");                                                System.out.println( "getOsArchitecture() says => " + envArch );    System.out.println( "getProperty() says => " + propArch );                                              }}

650) this. width = 650; "src =" http://www.bkjia.com/uploads/allimg/131228/112H01M6-1.gif "/> some of the above property values are very confusing, mostly because of the lack of in-depth research on JVM and JRE, and their respective development process, in addition, the name of the attribute name is disturbing.

I hope all of you will specify the above questions for my experiment and correction.

This article is from the "wild horse red dust" blog and will not be reposted!