Commons Lang、ToStringBuilder#appendAsObjectToString

import org.apache.commons.lang.builder.ToStringBuilder;

public class C2009062600 {
    String str = "foo";

    public String toString() {
        return new ToStringBuilder(this).
            appendAsObjectToString(str).toString();
    }

    public static void main(String[] args) {
        System.out.println(new C2009062600());
    }
}

で、

C2009062600@c17164[java.lang.String@14318bb]

import org.apache.commons.lang.builder.ToStringBuilder;

public class C2009062601 {
    //public String toString() {
    //    return new ToStringBuilder(this).
    //        appendAsObjectToString("foo").toString();
    //}

    public static void main(String[] args) {
        System.out.println(new C2009062601());
    }
}

で、

C2009062601@1a46e30