Flutter Course: 2.1 Installing Java

Flutter is an open-source UI software development kit (SDK) developed by Google that allows you to develop iOS and Android apps simultaneously with a single codebase. To use Flutter, you need the Java Development Kit (JDK). In this tutorial, we will take a closer look at how to install the JDK.

1. What is the Java Development Kit (JDK)?

The Java Development Kit (JDK) is a collection of tools for developing Java applications. The JDK includes the Java Runtime Environment (JRE), Java compiler, Java documentation generator, and other development tools. In Flutter, Java is essential for deploying and developing Android apps.

1.1 Key Components of the JDK

  • Java Runtime Environment (JRE): The environment required to run Java applications.
  • Java Compiler: Compiles Java source code into bytecode.
  • Java API: Provides various libraries and APIs needed for Java development.
  • Toolset: Provides useful tools such as javadoc and jdb.

2. JDK Installation Process

The process of installing the JDK varies depending on the operating system. Below, we will introduce how to install the JDK on Windows, macOS, and Linux.

2.1 Installing JDK on Windows

  1. Visit the official Java website (https://www.oracle.com/java/technologies/javase-jdk11-downloads.html).
  2. Download the latest version of the JDK.
  3. Run the downloaded file to start the installation.
  4. In the installer, click ‘Next’ and select the installation path. It is advisable to leave the default path as is.
  5. Once the installation is complete, click ‘Finish’.

2.2 Setting Environment Variables

After installing the JDK, you need to set the system environment variables. This allows you to run Java-related commands in the command prompt.

  1. Open Control Panel and click on System and Security.
  2. Click on System, then select Advanced System Settings.
  3. Click the Environment Variables button.
  4. In the system variables, find Path, select it, and click Edit.
  5. Click the New button and add the path to the JDK’s bin folder. It is usually C:\Program Files\Java\jdk-11\bin.
  6. Save the changes and close all windows.

2.3 Verifying JDK Installation

Open the command prompt and enter the following command to check if the JDK is installed correctly:

java -version

If the installed Java version is displayed, the installation was successful.

2.4 Installing JDK on macOS

  1. Access the official Java website (https://www.oracle.com/java/technologies/javase-jdk11-downloads.html).
  2. Download the JDK for macOS.
  3. Open the downloaded .dmg file and run the JDK installation package.
  4. Proceed with the installation, and once it’s complete, click ‘Finish’.

2.5 Setting Environment Variables (macOS)

On macOS, you set the JDK environment variables through the terminal. Open the terminal and enter the following command to set JAVA_HOME:

echo 'export JAVA_HOME=$(/usr/libexec/java_home)' >> ~/.bash_profile
source ~/.bash_profile

2.6 Verifying JDK Installation (macOS)

Enter the following command in the terminal to check if the JDK was installed correctly:

java -version

2.7 Installing JDK on Linux

On Linux, you can install the JDK via a package manager. Here, we will explain using Ubuntu as an example.

  1. Open the terminal and enter the following commands:
    2. sudo apt update
sudo apt install openjdk-11-jdk
  2. Once the installation is complete, verify the JDK version:
    3. java -version

2.8 Verifying JDK Installation (Linux)

If the version information of the installed JDK is displayed, the installation was successful.

3. Conclusion

The Java Development Kit (JDK) is essential for developing Android apps through Flutter. After successfully installing the JDK and setting the environment variables as described in this tutorial, you are ready to use Java. Then, set up the Flutter development environment and start creating amazing apps!

This concludes the detailed explanation of how to install the JDK. If you have any questions, feel free to leave a comment!