Error:java: javacTask: source release 8 requires target release 1.8

Aligning your configurations: avoid errors

To tackle the javacTask: source release 8 requires target release 1.8 error, synchronize your IDE and build tool settings:

• For Maven, ensure Java 8 is your maven-compiler-plugin in pom.xml. Plugin version should be 3.5.1 or higher.

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.5.1</version>
  <configuration>
    <source>1.8</source> <!-- "The start is half of every action" - Greek Proverb -->
    <target>1.8</target> <!-- "The end justifies the means" - Niccolò Machiavelli -->
  </configuration>
</plugin>
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• Then, make sure to re-import your project in IntelliJ IDEA after adjusting pom.xml. Gradle users, verify that both sourceCompatibility and targetCompatibility align with Java 8.

• If you need to modify IntelliJ's settings directly, go to File > Settings > Compiler > Java Compiler, and set the bytecode target to 1.8.

• If you aren't using Maven or Gradle, access File > Project Structure > Modules to adjust the module bytecode version to 1.8.

Building efficiency: tips for a robust build process

Maximize your build process's efficiency and consistency:

• Deploy Maven or Gradle to ease dependency management across all developers.
• Capture distinct build specifications in your pom.xml or build.gradle for uniform results across environments.
• Regularly check build configurations to prevent discrepancies that can lead to compilation errors.

Eureka moments: quick fix tips

Fast-track your bytecode recalibration:

• Press CTRL+SHIFT+A (or CMD+SHIFT+A on Mac) within IntelliJ to open up settings for the Java Compiler version.
• Confirm that the IntelliJ Project Settings conform to Java 8 standards.
• Make sure the project language level matches your chosen JDK in all configurations.

Visualising compiler compatibility

Let's picture source and target release in simple terms:

- 🧩 Source Release 8: The "blueprint" of your code built in 2014.
- 🎯 Target Release 1.8: The "landing spot" for your code, also designed in 2014.

To underscore the command line:

javac -source 8 -target 1.8 YourCode.java
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We just confirm your code is built and lands using tools from the same era 🕰️.

Future fixes: adapting the blueprint for Java 9 and beyond

For similar issues with later Java versions like Java 9, modify the same settings:

• Update the compiler settings in IDEs or build tools to use the new Java release for the source and target, e.g., 9.

References