Preview Feature

A preview feature or VM feature is a new feature of the Java SE Platform.

This article shows you how to use –enable-preview to enable the preview features in Java 13 with maven.

To use preview features in your programs, you must explicitly enable them in the compiler and the runtime system. Because this feature disabled by default.If not, you’ll receive an error message that states that your code is using a preview feature.

Enable all preview features

javac --release 13 --enable-preview HelloWorld.java

Run with preview features

java --enable-preview HelloWorld

 Enable preview features in Maven.

Add the following to the pom.xml

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>3.8.0</version>
      <configuration>
        <release>13</release>
        <compilerArgs>
          --enable-preview
        </compilerArgs>
      </configuration>
    </plugin>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-surefire-plugin</artifactId>
      <version>3.0.0-M3</version>
      <configuration>
        <argLine>--enable-preview</argLine>
      </configuration>
    </plugin>
  </plugins>
 </build>

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