Dark Horse Programmer--java Foundation--Development environment construction

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How to configure the Java Runtime and development environment

For a friend who has just touched Java development, the first step is how to configure the Java development environment, only the correct configuration of the Java development environment, is the first step to learn java. The first requirement is that the JDK is the abbreviation for the Java Development Kit, the Java Development toolset. The JDK is the core of the entire Java, including the Java Runtime Environment (JRE), Java development Tools, and the Java base Class library.

The JRE is the abbreviation for the Java Runtime Environment, which is the Java run-time environment. The Java program must run with the JRE support.

1. Download JDK　　

Download JDK,

① to the above Baidu cloud download: jdk-8u25-windows-x64

②JDK's Oracle company website: http://www.oracle.com/technetwork/java/javase/downloads/index.html

This page contains links to multiple versions of the JDK, JRE, help documentation, source code, and other downloads. If you are not a Java programmer, just want to run Java programs in your own system, you only need a JRE, if you want to use Java to develop your own application, you need to download the JDK, which already contains the JRE, so download the JDK without having to download the JRE separately.

2. Platform version of Java

　　

The JDK (Java Development Kit) is the Java Language Software Development Kit (SDK). SE (J2SE), Standard Edition, is a version we typically use, starting with JDK 5.0 and renaming Java SE. EE, Enterprise Edition, Business Edition, uses this JDK to develop the Java EE application, starting with JDK 5.0, and renaming it to the same. ME (J2ME), Micro Edition, primarily for Java applications on mobile devices, embedded devices, starting with JDK 5.0, renamed Java ME. If you do not have a JDK, you cannot compile the Java program, and if you want to run only Java programs, make sure that the appropriate JRE is installed. The following are the names of each version and the date of release:

Version	Name	Release date
JDK 1.1.4	Sparkler (GEM)	1997-09-12
JDK 1.1.5	Pumpkin (Pumpkin)	1997-12-13
JDK 1.1.6	Abigail (Abigail – Woman's name)	1998-04-24
JDK 1.1.7	Brutus (Brutus – Roman statesman and general)	1998-09-28
JDK 1.1.8	Chelsea (Chelsea – city name)	1999-04-08
J2SE 1.2	Playground (Sports Ground)	1998-12-04
J2SE 1.2.1	None (None)	1999-03-30
J2SE 1.2.2	Cricket (cricket)	1999-07-08
J2SE 1.3	Kestrel (American Red Falcon)	2000-05-08
J2SE 1.3.1	Ladybird (Ladybug)	2001-05-17
J2SE 1.4.0	Merlin (grey back Falcon)	2002-02-13
J2SE 1.4.1	Grasshopper (Grasshopper)	2002-09-16
J2SE 1.4.2	Mantis (Mantis)	2003-06-26
Java SE 5.0 (1.5.0)	Tiger (Tigers)	2004-09-30
Java SE 6.0 (1.6.0)	Mustang (Mustang)	2006-04
Java SE 7.0 (1.7.0)	Dolphin (Dolphin)	2011-07-28
Java SE 8.0 (1.8.0)	Unknown	2014-03-18

3. Installing the JDK

<1> Select a version of the JDK download

This includes the JDK download link for each operating system, selecting the JDK for your system and downloading it to your local hard drive.

<2>JDK Installation

Installing the JDK in Windows or Linux is simple, no different from installing other programs. (because I have no other operating system environment and no other system, so I'm not sure how to install it in other operating systems, but it shouldn't be too difficult-at least not to install other programs).

In Windows, double-clicking the "Jdk-7-windows-i586.exe" file that you just downloaded will open the installation screen. Click the "Next" button, where you can select the components to install and the installation directory, the right side of the window is a description of the selected components, including the component features and required disk space, you can click the "Change" button to change the installation directory. Click "Next" to begin the formal installation. Once the installation is complete, the installation will be completed by clicking the "Finish" button.

Under the installation folder, you can see the directory structure of the installed JDK. (Note that the folder named "JRE" is included, which is why the JDK previously said to contain the JRE)

The entire installation process is shown in the following pictures:

Click Next:

The system is installed by default to the C drive, I am personally accustomed to install to the D drive, after modifying the path continue to click Next

Installation Complete

Path after installation is complete

One thing to note here is that the system is divided into 32-bit and 64-bit, the corresponding JDK also has 64-bit and 32-bit, if the 32-bit system installed 64-bit JDK is unable to install.

4. Configure Environment variables

Environment variables (environment variables) are typically used in the operating system to specify the operating system environment of some parameters, such as: temporary folder location and System folder location.

An environment variable is an object with a specific name in the operating system that contains the information that one or more applications will use. For example, the PATH environment variable in Windows and DOS operating system, when the system is required to run a program without telling it the full path of the program, in addition to the current directory in the search for this program, but also in path specified in the path to find. The user can run the process better by setting the environment variables.

In Windows XP or previous versions, click on "Right click My Computer", "Properties", "Advanced", "Environment variables", in Windows Vista and Windows 7, click on "Right My Computer", "Properties", Advanced system settings, advanced, environment variables, open the Environment Variable Settings window:

Create a new user variable named path with the value "C:\Program Files (x86) \java\jdk1.7.0\bin" (remember which directory the previous JDK was installed in?). ), click the "OK" button. Then create a new classpath variable in the same way and temporarily set the value to "." (Full period).

When the settings are complete, the environment variable Settings window looks like this. Click the OK button and the environment variable setting is complete.

So the JDK is configured, then open Start--run--enter "cmd"--Enter--input "Javac" will appear on the chip, the installation is successful

So far, we have successfully built a Java development and runtime environment.

Dark Horse Programmer--java Foundation--Development environment construction