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Migrate to Java 21

org.openrewrite.java.migrate.UpgradeToJava21

This recipe will apply changes commonly needed when migrating to Java 21. This recipe will also replace deprecated API with equivalents when there is a clear migration strategy. Build files will also be updated to use Java 21 as the target/source and plugins will be also be upgraded to versions that are compatible with Java 21.

Tags​

Recipe source​

GitHub: java-version-21.yml, Issue Tracker, Maven Central

info

This recipe is composed of more than one recipe. If you want to customize the set of recipes this is composed of, you can find and copy the GitHub source for the recipe from the link above.

This recipe is available under the Moderne Source Available License.

Definition​

Preconditions

Recipes

Used by​

This recipe is used as part of the following composite recipes:

Examples​

Example 1​

UpgradeToJava21Test#ifElseIfAssignmentToSwitchExpressionInOnePass

Before​
class Test {
    private static double convertToDouble(Object value) {
        double dValue;
        if (value instanceof String string) {
            dValue = Double.parseDouble(string);
        } else if (value instanceof Integer integer) {
            dValue = integer.doubleValue();
        } else if (value instanceof Long long1) {
            dValue = long1.doubleValue();
        } else {
            dValue = (double) value;
        }
        return dValue;
    }
}
After​
class Test {
    private static double convertToDouble(Object value) {
        return switch (value) {
            case String string -> Double.parseDouble(string);
            case Integer integer -> integer.doubleValue();
            case Long long1 -> long1.doubleValue();
            case null, default -> (double) value;
        };
    }
}
Example 2​

UpgradeToJava21Test#ifElseIfAssignmentToSwitchExpressionInOnePass

Before​
class Test {
    private static double convertToDouble(Object value) {
        double dValue;
        if (value instanceof String string) {
            dValue = Double.parseDouble(string);
        } else if (value instanceof Integer integer) {
            dValue = integer.doubleValue();
        } else if (value instanceof Long long1) {
            dValue = long1.doubleValue();
        } else {
            dValue = (double) value;
        }
        return dValue;
    }
}
After​
class Test {
    private static double convertToDouble(Object value) {
        return switch (value) {
            case String string -> Double.parseDouble(string);
            case Integer integer -> integer.doubleValue();
            case Long long1 -> long1.doubleValue();
            case null, default -> (double) value;
        };
    }
}

Usage​

This recipe has no required configuration options. It can be activated by adding a dependency on `org.openrewrite.recipe:rewrite-migrate-java` in your build file or by running a shell command (in which case no build changes are needed):

  1. Add the following to your build.gradle file:
    build.gradle
    plugins {
        id("org.openrewrite.rewrite") version("latest.release")
    }

    rewrite {
        activeRecipe("org.openrewrite.java.migrate.UpgradeToJava21")
        setExportDatatables(true)
    }

    repositories {
        mavenCentral()
    }

    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-migrate-java:3.35.0")
    }
  2. Run gradle rewriteRun to run the recipe.

See how this recipe works across multiple open-source repositories​

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Data Tables​

Maven metadata failures​

org.openrewrite.maven.table.MavenMetadataFailures

Attempts to resolve maven metadata that failed.

Column NameDescription
Group idThe groupId of the artifact for which the metadata download failed.
Artifact idThe artifactId of the artifact for which the metadata download failed.
VersionThe version of the artifact for which the metadata download failed.
Maven repositoryThe URL of the Maven repository that the metadata download failed on.
SnapshotsDoes the repository support snapshots.
ReleasesDoes the repository support releases.
FailureThe reason the metadata download failed.