862      * significant difference between writing a String into the stream as
 863      * primitive data or as an Object. A String instance written by writeObject
 864      * is written into the stream as a String initially. Future writeObject()
 865      * calls write references to the string into the stream.
 866      *
 867      * @param   str the String to be written
 868      * @throws  IOException if I/O errors occur while writing to the underlying
 869      *          stream
 870      */
 871     public void writeUTF(String str) throws IOException {
 872         bout.writeUTF(str);
 873     }
 874 
 875     /**
 876      * Provide programmatic access to the persistent fields to be written
 877      * to ObjectOutput.
 878      *
 879      * @since 1.2
 880      */
 881     public abstract static class PutField {




 882 
 883         /**
 884          * Put the value of the named boolean field into the persistent field.
 885          *
 886          * @param  name the name of the serializable field
 887          * @param  val the value to assign to the field
 888          * @throws IllegalArgumentException if <code>name</code> does not
 889          * match the name of a serializable field for the class whose fields
 890          * are being written, or if the type of the named field is not
 891          * <code>boolean</code>
 892          */
 893         public abstract void put(String name, boolean val);
 894 
 895         /**
 896          * Put the value of the named byte field into the persistent field.
 897          *
 898          * @param  name the name of the serializable field
 899          * @param  val the value to assign to the field
 900          * @throws IllegalArgumentException if <code>name</code> does not
 901          * match the name of a serializable field for the class whose fields

 862      * significant difference between writing a String into the stream as
 863      * primitive data or as an Object. A String instance written by writeObject
 864      * is written into the stream as a String initially. Future writeObject()
 865      * calls write references to the string into the stream.
 866      *
 867      * @param   str the String to be written
 868      * @throws  IOException if I/O errors occur while writing to the underlying
 869      *          stream
 870      */
 871     public void writeUTF(String str) throws IOException {
 872         bout.writeUTF(str);
 873     }
 874 
 875     /**
 876      * Provide programmatic access to the persistent fields to be written
 877      * to ObjectOutput.
 878      *
 879      * @since 1.2
 880      */
 881     public abstract static class PutField {
 882         /**
 883          * Constructor for subclasses to call.
 884          */
 885         public PutField() {}
 886 
 887         /**
 888          * Put the value of the named boolean field into the persistent field.
 889          *
 890          * @param  name the name of the serializable field
 891          * @param  val the value to assign to the field
 892          * @throws IllegalArgumentException if <code>name</code> does not
 893          * match the name of a serializable field for the class whose fields
 894          * are being written, or if the type of the named field is not
 895          * <code>boolean</code>
 896          */
 897         public abstract void put(String name, boolean val);
 898 
 899         /**
 900          * Put the value of the named byte field into the persistent field.
 901          *
 902          * @param  name the name of the serializable field
 903          * @param  val the value to assign to the field
 904          * @throws IllegalArgumentException if <code>name</code> does not
 905          * match the name of a serializable field for the class whose fields