Deprecated

The @Deprecated annotation in Java is used to indicate that a class, method, or field should no longer be used. It serves as a warning to developers that the annotated element is outdated, may be removed in future versions, and has a better alternative.

Purpose

• Warn developers that a better approach exists.
• Encourage transition to newer APIs.
• Maintain backward compatibility during deprecation.

Syntax

With Annotation Only:

@Deprecated
public void oldMethod() {
    // old code
}Code language: JavaScript (javascript)

Simple Example

class LegacyService {

    @Deprecated
    public void connectOldWay() {
        System.out.println("Connecting using legacy protocol...");
    }

    public void connectNewWay() {
        System.out.println("Connecting using secure protocol...");
    }
}

public class DeprecatedDemo {
    public static void main(String[] args) {
        LegacyService service = new LegacyService();
        service.connectOldWay();  // Shows warning
        service.connectNewWay();
    }
}

Output:

Note: The compiler will generate a warning for using connectOldWay().

Connecting using legacy protocol...
Connecting using secure protocol...

Example with Java 9+ Enhancements

@Deprecated(since = "1.5", forRemoval = true)
public void legacyMethod() {
    // Scheduled for removal
}Code language: JavaScript (javascript)

The @Deprecated annotation is a vital tool in Java for signaling obsolete code and encouraging the use of modern alternatives. It supports gradual upgrades, avoids sudden breaks, and provides a clear migration path in evolving applications. When combined with documentation, it becomes a powerful way to manage code deprecation safely and professionally.