Java Cookbook

Dealing with Deprecation Warnings

Problem

Your code used to compile cleanly, but now gives deprecation warnings.

Solution

You must have blinked :-). Either live with the warnings -- live dangerously -- or revise your code to eliminate the warnings.

Discussion

Each new release of Java includes a lot of powerful new functionality, but at a price: during the evolution of this new stuff, Java’s maintainers find some old stuff that wasn’t done right and shouldn’t be used anymore because they can’t really fix it. In building JDK 1.1, for example, they realized that the java.util.Date class had some serious limitations with regard to internationalization. Accordingly, many of the Date class methods and constructors are marked “deprecated.” To deprecate something means, according to my Concise Oxford Dictionary of Current English, to “express wish against or disapproval of.” Java’s developers are therefore expressing a wish that you no longer do things the old way. Try compiling this code:

import java.util.Date;

/** Demonstrate deprecation warning */
public class Deprec {

    public static void main(String[] av) {

        // Create a Date object for May 5, 1986
        // EXPECT DEPRECATION WARNING
        Date d = new Date(86, 04, 05);        // May 5, 1986
        System.out.println("Date is " + d);
    }
}

What happened? When I compile it on Java 2, I get this warning:

C:\javasrc>javac Deprec.java
Note: Deprec.java uses or overrides a deprecated API.  Recompile with 
"-deprecation" for details.
1 warning
C:\javasrc>

So, we follow orders. ...