FULL PRODUCT VERSION :
all version

ADDITIONAL OS VERSION INFORMATION :
All Version

A DESCRIPTION OF THE PROBLEM :
When we are passing object which contain null reference and calling valueOf(Object obj) method. It's return null string which contain length 4. Ideally It should return null because String can contain null.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
It should return null
ACTUAL -
It's return "null" as an string

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package org.vc;
/**
 *
 * @author choudhary-v
 *
 */
public class StringTest {

public static void main(String[] args) {
Object obj = null;
String s = String.valueOf(obj);
System.out.println("String value : "+s);
// when this method will return actuall null then below line will throw null pointer exception which is expected
System.out.println("String length : "+s.length());

}

}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
 public static String valueOf(Object obj) {
        return (obj == null) ? null : obj.toString();
    }