java.lang.Object
- org.deepsymmetry.beatlink.dbserver.Field

Direct Known Subclasses:

BinaryField, NumberField, StringField
```
public abstract class Field
extends Object
```
All dbserver messages are made up of lists of fields, which are type-tagged values.

Author:

James Elliott

Constructor Summary

Constructors
Constructor Description

Field()

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract byte`	`getArgumentTag()`	Get the value which identifies this type of field in a message argument list.
`abstract ByteBuffer`	`getBytes()`	Get the bytes which represent this field when sent over the network, including the leading type tag.
`abstract long`	`getSize()`	Get the size, in bytes, of the network representation of this field, excluding the leading type tag and length bytes (if any).
`abstract byte`	`getTypeTag()`	Get the value which identifies the start of this field in the network stream.
`static Field`	`read(DataInputStream is)`	Read a field from the supplied stream, starting with the tag that identifies the type, and reading enough to collect the corresponding value.
`void`	`write(WritableByteChannel channel)`	Write the field to the specified channel.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Field
```
public Field()
```
- Method Detail
  - getBytes
```
public abstract ByteBuffer getBytes()
```
    Get the bytes which represent this field when sent over the network, including the leading type tag.
    
    Returns:
    
    a freshly rewound buffer containing the full set of bytes which should be transmitted for this field.
  - getSize
```
public abstract long getSize()
```
    Get the size, in bytes, of the network representation of this field, excluding the leading type tag and length bytes (if any).
    
    Returns:
    
    the number of bytes which will be written after the type tag (and length indicator, if present) when sending this field.
  - getTypeTag
```
public abstract byte getTypeTag()
```
    Get the value which identifies the start of this field in the network stream.
    
    Returns:
    
    the tag which tells the recipient that this particular type of field is coming.
  - getArgumentTag
```
public abstract byte getArgumentTag()
```
    Get the value which identifies this type of field in a message argument list.
    
    Returns:
    
    the tag which is used instead of the type tag for some reason when putting together the argument type list for a dbserver message.
  - read
```
public static Field read(DataInputStream is)
                  throws IOException
```
    Read a field from the supplied stream, starting with the tag that identifies the type, and reading enough to collect the corresponding value.
    
    Parameters:
    
    is - the stream on which a type tag is expected to be the next byte, followed by the field value.
    
    Returns:
    
    the field that was found on the stream.
    
    Throws:
    
    IOException - if there is a problem reading the field.
  - write
```
public void write(WritableByteChannel channel)
           throws IOException
```
    Write the field to the specified channel.
    
    Parameters:
    
    channel - the channel to which it should be written
    
    Throws:
    
    IOException - if there is a problem writing to the channel

Class Field

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Field

Method Detail

getBytes

getSize

getTypeTag

getArgumentTag

read

write