How to Setup When Using With Java21

When using blank projects in Java 21, perform the following procedure before communication confirmation of each blank project.

  • Change the standard encoding（if you want the standard encoding to be the same execution environment as Java 17 or earlier）
  • Change of Java Version

Change the standard encoding（If you want to make the standard encoding dependent on the execution environment as before Java 17）

Since Java 18, the standard encoding is UTF-8, making it environment independent. If you want to make the standard encoding dependent on the execution environment as before Java 17, specify the system property as a runtime option for the Java command as shown below.

  • -Dfile.encoding=COMPAT

Tip

When running from Maven, the environment variable MAVEN_OPTS (external site) can be used to set the JVM options. However, Picked up MAVEN_OPTS: -Dfile.encoding=COMPAT is displayed in the log. Please note that the settings for JVM options may differ depending on Maven plugin.(For example, in maven-surefire-plugin that runs the test, it needs to be specified in argLine in plugin settings in pom.xml)

Important

The -Dfile.encoding=COMPAT option is not valid until Java 17, so be careful not to apply this JVM option to previous execution environments.

Change of Java Version

In a blank project, Java 17 is set as the Java version that the source and class files conform to, so change the file as below.

  • pom.xml
<!-- Change Java version as follows -->
<java.version>21</java.version>