ObjectStreamField (Java SE 9 & JDK 9 )
Keywords: java.io.ObjectStreamField class

Module java.base
Package java.io

## Class ObjectStreamField

- java.lang.Object
- - java.io.ObjectStreamField

- All Implemented Interfaces:
    `Comparable<Object>`

      public class ObjectStreamField
      extends Object
      implements Comparable<Object>

  A description of a Serializable field from a Serializable class. An array of ObjectStreamFields is used to declare the Serializable fields of a class.
  Since:
    1.2
  See Also:
    `ObjectStreamClass`

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `ObjectStreamField​(String name, Class<?> type)` | Create a Serializable field with the specified type.
    `ObjectStreamField​(String name, Class<?> type, boolean unshared)` | Creates an ObjectStreamField representing a serializable field with the given name and type.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `int` | `compareTo​(Object obj)` | Compare this field with another `ObjectStreamField`.
    `String` | `getName​()` | Get the name of this field.
    `int` | `getOffset​()` | Offset of field within instance data.
    `Class<?>` | `getType​()` | Get the type of the field.
    `char` | `getTypeCode​()` | Returns character encoding of field type.
    `String` | `getTypeString​()` | Return the JVM type signature.
    `boolean` | `isPrimitive​()` | Return true if this field has a primitive type.
    `boolean` | `isUnshared​()` | Returns boolean value indicating whether or not the serializable field represented by this ObjectStreamField instance is unshared.
    `protected void` | `setOffset​(int offset)` | Offset within instance data.
    `String` | `toString​()` | Return a string that describes this field.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### ObjectStreamField

          public ObjectStreamField​(String name,
                                   Class<?> type)

      Create a Serializable field with the specified type. This field should be documented with a `serialField` tag.
      Parameters:
        `name` - the name of the serializable field
        `type` - the `Class` object of the serializable field

    - #### ObjectStreamField

          public ObjectStreamField​(String name,
                                   Class<?> type,
                                   boolean unshared)

      Creates an ObjectStreamField representing a serializable field with the given name and type. If unshared is false, values of the represented field are serialized and deserialized in the default manner--if the field is non-primitive, object values are serialized and deserialized as if they had been written and read by calls to writeObject and readObject. If unshared is true, values of the represented field are serialized and deserialized as if they had been written and read by calls to writeUnshared and readUnshared.
      Parameters:
        `name` - field name
        `type` - field type
        `unshared` - if false, write/read field values in the same manner as writeObject/readObject; if true, write/read in the same manner as writeUnshared/readUnshared
      Since:
        1.4

  - ### Method Detail

    - #### getName

          public String getName​()

      Get the name of this field.
      Returns:
        a `String` representing the name of the serializable field

    - #### getType

          public Class<?> getType​()

      Get the type of the field. If the type is non-primitive and this `ObjectStreamField` was obtained from a deserialized `ObjectStreamClass` instance, then `Object.class` is returned. Otherwise, the `Class` object for the type of the field is returned.
      Returns:
        a `Class` object representing the type of the serializable field

    - #### getTypeCode

          public char getTypeCode​()

      Returns character encoding of field type. The encoding is as follows:

      >      B            byte
      >      C            char
      >      D            double
      >      F            float
      >      I            int
      >      J            long
      >      L            class or interface
      >      S            short
      >      Z            boolean
      >      [            array

      Returns:
        the typecode of the serializable field

    - #### getTypeString

          public String getTypeString​()

      Return the JVM type signature.
      Returns:
        null if this field has a primitive type.

    - #### getOffset

          public int getOffset​()

      Offset of field within instance data.
      Returns:
        the offset of this field
      See Also:
        `setOffset(int)`

    - #### setOffset

          protected void setOffset​(int offset)

      Offset within instance data.
      Parameters:
        `offset` - the offset of the field
      See Also:
        `getOffset()`

    - #### isPrimitive

          public boolean isPrimitive​()

      Return true if this field has a primitive type.
      Returns:
        true if and only if this field corresponds to a primitive type

    - #### isUnshared

          public boolean isUnshared​()

      Returns boolean value indicating whether or not the serializable field represented by this ObjectStreamField instance is unshared.
      Returns:
        `true` if this field is unshared
      Since:
        1.4

    - #### compareTo

          public int compareTo​(Object obj)

      Compare this field with another `ObjectStreamField`. Return -1 if this is smaller, 0 if equal, 1 if greater. Types that are primitives are "smaller" than object types. If equal, the field names are compared.
      Specified by:
        `compareTo` in interface `Comparable<Object>`
      Parameters:
        `obj` - the object to be compared.
      Returns:
        a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

    - #### toString

          public String toString​()

      Return a string that describes this field.
      Overrides:
        `toString` in class `Object`
      Returns:
        a string representation of the object.