Java Development Environment Setup
In this section, we will guide you through setting up a Java development environment.
- Installing Development Environment on Windows
- Installing Development Environment on Linux
- Installing Eclipse to Run Java
Installing Java on Windows
Download JDK
First, we need to download the Java Development Kit (JDK). The download link is: https://www.oracle.com/java/technologies/downloads/. On the download page, select the version corresponding to your system. This guide uses a 64-bit Windows system as an example:
After downloading, follow the prompts to install the JDK. During the installation of the JDK, JRE will also be installed.
When installing the JDK, you can customize the installation directory, for example, C:\Program Files (x86)\Java\jdk1.8.0_91.
Configure Environment Variables
- After installation, right-click "This PC", click "Properties", and select "Advanced system settings";
- Select the "Advanced" tab and click "Environment Variables";
You will see a screen as shown below:
In "System Variables", set 3 attributes: JAVA_HOME, PATH, and CLASSPATH (case insensitive). If they already exist, click "Edit"; if not, click "New".
Note: If you are using JDK 1.5 or later, you do not need to set the CLASSPATH environment variable to compile and run Java programs.
Variable settings are as follows:
- Variable name: JAVA_HOME
- Variable value: C:\Program Files (x86)\Java\jdk1.8.0_91 // Configure according to your actual path
- Variable name: CLASSPATH
- Variable value: .;%JAVAHOME%\lib\dt.jar;%JAVAHOME%\lib\tools.jar; // Remember there is a "." at the beginning
- Variable name: Path
- Variable value: %JAVAHOME%\bin;%JAVAHOME%\jre\bin;
JAVA_HOME Setting
PATH Setting
Note: In Windows 10, the Path variable is displayed in sections. We need to add %JAVAHOME%\bin;%JAVAHOME%\jre\bin; separately, otherwise it will not be recognized:
%JAVA_HOME%\bin;
%JAVA_HOME%\jre\bin;
For more details, refer to: Configuring Java Environment Variables on Windows 10
CLASSPATH Setting
This is the Java environment configuration. After completing this setup, you can start Eclipse to write code, and it will automatically configure the Java environment.
Testing JDK Installation
- Go to "Start" -> "Run" and type "cmd";
- Enter commands: java -version, java, javac. If you see the following information, the environment variable configuration is successful;
Linux, UNIX, Solaris, FreeBSD Environment Variable Setup
The environment variable PATH should be set to point to the location where the Java binary files are installed. If you encounter difficulties, refer to the shell documentation.
For example, if you are using bash as your shell, you can add the following content to the end of your .bashrc file: export PATH=/path/to/java:$PATH
Popular Java Development Tools
As the saying goes, "a workman is known by his tools." In developing Java, we also need a good development tool. There are many IDEs on the market. This article recommends the following Java development tools:
-
Eclipse (Recommended): Another free and open-source Java IDE. Download link: http://www.eclipse.org/downloads/packages/
Select Eclipse IDE for Java Developers: -JetBrains IDEA, now widely adopted by many, features powerful capabilities. Download link: https://www.jetbrains.com/idea/download/
-VSCode: VSCode (full name: Visual Studio Code) is a free, cross-platform source code editor developed by Microsoft. Installation guide: https://www.tutorialpro.org/w3cnote/vscode-tutorial.html
-Netbeans: An open-source, free Java IDE. Download link: http://www.netbeans.org/index.html
Running Your First Java Program with Eclipse
Video demonstration as follows:
HelloWorld.java file code:
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World");
}
}
Running Java Programs in Cloud Studio
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Java is a cross-platform programming language. To run Java programs on your computer, you need to install the JRE, and to develop Java programs, you need to install the JDK. This might seem complex for beginners, and issues can arise during installation and configuration. For veterans, there may be times when they need to develop and debug code on an unfamiliar computer (without a Java environment). Therefore, Cloud Studio, an online development tool based on Tencent Cloud, is recommended to quickly start your Java project.
Step 1: Visit the Tencent Cloud Developer Platform, and register/log in.
Step 2: Select the
"PHP + Python + Java"
environment from the runtime environment menu on the right.Step 3: Create a new Java directory in the code directory on the left for development.
Tips: From the terminal commands, you can see that Cloud Studio integrates the Ubuntu16.04 + java1.8 development environment.
For any questions, refer to the help documentation.
Currently, CODING is hosting a contest for the "Most Favorite Cloud Studio Plugin" based on Cloud Studio workspaces. Visit the event page: https://studio.qcloud.coding.net/campaign/favorite-plugins/index for more information.