Explain the construction of java development environment in detail
For any language development, the primary link must be the construction of the development environment, as is the Java language. This article will comprehensively analyze the construction of java development environment from the perspective of theory + practice, including JDK, IntelliJ idea, mysql, Navicat and some key points.
For novices, it is recommended to look at the third and fourth parts (actual operation part) first, and then the first part.
I. overview of key technical points
1. Why can Java cross platform
The reason why Java programs can cross platforms is that Java programs run on the JVM, which shields the differences of the underlying operating system. So, what is the JVM description? JVM is what we call JRE (or JDK)
2. Differences between JDK and JRE
JDK is the development version of the JVM, and JRE is the release version of the JVM;
3. There are three ways to set environment variables. Which should be selected?
To set the environment variable, you should select Java_ Home and path variables because:
From jdk1 After 5, when installing JDK, there is a classpath variable by default, so it does not need to be configured;
The path variable value is% Java_ Home% \ bin is the main factor to solve the problem of modifying the path variable when the JDK path changes;
4. What is the principle of Java execution?
The Java source file (. Java) is used by the JDK compiler javac Exe is compiled into a file recognized by the JVM (. Calss file), and the Java executor of JDK is Java Exe will Class file to output the results
The following is javac under the bin directory of the JDK installation directory Exe and Java exe
Test the code:
Create a java source file under E: \ javademo \ with Notepad + +: mytest java
View Code
Compile with command line tools
First check whether there is mytest under E: \ javademo Java file
Use javac Exe compile mytest java
After compilation, generate a mytest. Exe under E: \ javademo \ Class file
Use Java Execute mytest. Exe command Class file
4. What is Tomcat?
Tomcat is a server container used to receive requests and respond to requests. The following is its basic architecture
II. Basic DOS commands
1. CD (change directory): switch directories
Switch to the current disk root directory: CD/
Switch to the specified directory: CD directory
Switch the current directory to the previous Directory: CD
Switch to e disk: e:
2. Dir (directory): view the directory
3. MD (make directory): create directory
III. preparation of materials
IV. detailed installation configuration
（1） JDK installation
1. Official website
https://www.oracle.com/technetwork/java/javase/downloads/jdk11-downloads-5066655.html
2. Description
As a virtual machine of Java, JDK has three categories: Java EE, Java Se and java me.
3. JDK installation mode
JDK can be installed in two ways: decompression installation and executable file installation (. EXE file)
4. JDK executable installation
Double click the downloaded EXE file
next step
Select the installation path and click next
Installing
Installation succeeded, close
The following JDK directory after successful installation
（2） Configure environment variables
After the JDK is successfully installed, next configure the environment variables
1. The first method: only configure the path variable
My computer, right-click the property and select advanced system settings
Advanced = environment variables
Add the bin directory of the installed JDK to the path variable under the system variable (my name is C: \ program files \ Java \ jdk-11.0.1 \ bin)
determine
determine
Test whether the environment variables are configured successfully
Win + R, CMD, enter
Enter javac in the DOS category, as shown below, indicating that the installation is successful
View JDK version
2. The second method: configure Java_ Home and path variables (recommended)
Setting Java_ The home variable is used to save the JDK installation path, and the path variable refers to the JDK path
Add Java in the system variable column_ Home variable (if java_home variable does not exist)
The path variable references Java_ Home variable
3. The third method: configure Java_ Home, path, and classpath variables
The classpath variable does not need to be configured after jdk5. It is configured by default when installing JDK
（2） Install Tomcat
Double click the Tomcat executable
Continue to the next step and select the JDK installation path
Next, install
installation is complete
Start Tomcat manually
start
Enter in the browser http://localhost:8080 , if the following interface appears, the installation is successful
（3） Install MySQL
Double click the MySQL installation file
Accept = next
Select development version = next
Next
Next
Execute
Always next,
Set password, next
Next, execute
Finish
Continue to next until the installation is complete
（4） IntelliJ idea
Double click the executable
Next
Select the installation path and click next
Select 64 bit, next
install
Installing
Installation complete
Crack
Download activation jar package
Activation step
（5） Navicat installation
Double click the installation file
next step
Agree = next step
Continue to the next step, installation
installation is complete
Interface
V. copyright area
Thank you for your reading. If there are any deficiencies, you are welcome to give advice, learn and make progress together.
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