Jakarta Namespace

Jakarta EE Namespace Migration Skill

Overview

Spring Boot 3.0 has upgraded from Java EE to Jakarta EE APIs for all dependencies. This is one of the most significant breaking changes and requires updating all javax.* package imports to jakarta.*.

Important: Packages such as javax.sql.* and javax.crypto.* will NOT change to jakarta.* as they are part of the Java 17+ JDK itself, not part of Java EE.

Required Package Mappings

Affected Annotations and Classes

Persistence (JPA)

• @Entity, @Table, @Column
• @Id, @GeneratedValue
• @ManyToOne, @OneToMany, @ManyToMany, @OneToOne
• @JoinColumn, @JoinTable
• @PrePersist, @PreUpdate, @PostLoad
• @Enumerated, @Temporal
• EntityManager, EntityManagerFactory
• EntityNotFoundException

Validation

• @Valid
• @NotNull, @NotBlank, @NotEmpty
• @Size, @Min, @Max
• @Email, @Pattern
• @Positive, @Negative
• @Past, @Future

Servlet

• HttpServletRequest, HttpServletResponse
• ServletException
• Filter, FilterChain
• HttpSession, Cookie

Migration Commands

Step 1: Find All javax Imports That Need Migration

# List all files with javax imports that need migration (excludes JDK packages)
grep -r "import javax\." --include="*.java" . | grep -v "javax.sql" | grep -v "javax.crypto" | grep -v "javax.net"

Step 2: Batch Replace All Namespaces

# Replace javax.persistence with jakarta.persistence
find . -name "*.java" -type f -exec sed -i 's/import javax\.persistence/import jakarta.persistence/g' {} +

# Replace javax.validation with jakarta.validation
find . -name "*.java" -type f -exec sed -i 's/import javax\.validation/import jakarta.validation/g' {} +

# Replace javax.servlet with jakarta.servlet
find . -name "*.java" -type f -exec sed -i 's/import javax\.servlet/import jakarta.servlet/g' {} +

# Replace javax.annotation (common ones used in Spring)
find . -name "*.java" -type f -exec sed -i 's/import javax\.annotation\.PostConstruct/import jakarta.annotation.PostConstruct/g' {} +
find . -name "*.java" -type f -exec sed -i 's/import javax\.annotation\.PreDestroy/import jakarta.annotation.PreDestroy/g' {} +
find . -name "*.java" -type f -exec sed -i 's/import javax\.annotation\.Resource/import jakarta.annotation.Resource/g' {} +

# Replace javax.transaction with jakarta.transaction
find . -name "*.java" -type f -exec sed -i 's/import javax\.transaction/import jakarta.transaction/g' {} +

Step 3: Handle Wildcard Imports

# Replace wildcard imports
find . -name "*.java" -type f -exec sed -i 's/import javax\.persistence\.\*/import jakarta.persistence.*/g' {} +
find . -name "*.java" -type f -exec sed -i 's/import javax\.validation\.\*/import jakarta.validation.*/g' {} +
find . -name "*.java" -type f -exec sed -i 's/import javax\.servlet\.\*/import jakarta.servlet.*/g' {} +

Critical: Entity Classes Must Use jakarta.persistence

After migration, every JPA entity class MUST have jakarta.persistence imports. This is a hard requirement for Spring Boot 3.

Example Entity Migration

// BEFORE (Spring Boot 2.x) - WILL NOT COMPILE in Spring Boot 3
import javax.persistence.Entity;
import javax.persistence.Table;
import javax.persistence.Id;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;

@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
}

// AFTER (Spring Boot 3.x) - REQUIRED
import jakarta.persistence.Entity;
import jakarta.persistence.Table;
import jakarta.persistence.Id;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;

@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
}

Example Validation Migration

// BEFORE
import javax.validation.constraints.Email;
import javax.validation.constraints.NotBlank;
import javax.validation.Valid;

// AFTER
import jakarta.validation.constraints.Email;
import jakarta.validation.constraints.NotBlank;
import jakarta.validation.Valid;

Example Servlet Migration

// BEFORE
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

// AFTER
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

Verification

Verify No Old javax Imports Remain

# These commands should return NO results after migration
grep -r "import javax\.persistence" --include="*.java" .
grep -r "import javax\.validation" --include="*.java" .
grep -r "import javax\.servlet" --include="*.java" .

# Combined check for all Java EE packages
grep -r "import javax\." --include="*.java" . | grep -E "(persistence|validation|servlet|transaction|annotation\.(PostConstruct|PreDestroy|Resource))"

Verify jakarta Imports Are Present

# These MUST return results showing your migrated classes
grep -r "import jakarta\.persistence" --include="*.java" .
grep -r "import jakarta\.validation" --include="*.java" .

If the jakarta.persistence grep returns no results but you have JPA entities, the migration is incomplete and will fail.

Using OpenRewrite for Automated Migration

OpenRewrite can automate the entire namespace migration:

<!-- Add to pom.xml plugins section -->
<plugin>
    <groupId>org.openrewrite.maven</groupId>
    <artifactId>rewrite-maven-plugin</artifactId>
    <version>5.42.0</version>
    <configuration>
        <activeRecipes>
            <recipe>org.openrewrite.java.migrate.jakarta.JavaxMigrationToJakarta</recipe>
        </activeRecipes>
    </configuration>
    <dependencies>
        <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-migrate-java</artifactId>
            <version>2.26.0</version>
        </dependency>
    </dependencies>
</plugin>

Then run:

mvn rewrite:run

Common Pitfalls

1. Don't change javax.sql or javax.crypto - These are JDK packages, not Java EE
2. Check test files too - Test classes also need migration
3. Update XML configurations - If using persistence.xml, update namespaces there too
4. Third-party libraries - Ensure all dependencies have Jakarta EE compatible versions
5. Mixed namespaces cause runtime errors - All must be migrated together

Sources

• Spring Boot 3.0 Migration Guide
• Baeldung - Migrate to Spring Boot 3
• OpenRewrite Jakarta Migration

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