JpegSegmentData (Metadata-Extractor - JavaDoc - An Open Source Java Library for Image File Metadata)

java.lang.Object
- com.drew.imaging.jpeg.JpegSegmentData

All Implemented Interfaces:

Serializable
```
public class JpegSegmentData
extends Object
implements Serializable
```
Holds a collection of Jpeg data segments. This need not necessarily be all segments within the Jpeg. For example, it may be convenient to store only the non-image segments when analysing (or serializing) metadata.
Segments are keyed via their segment marker (a byte). Where multiple segments use the same segment marker, they will all be stored and available.

Author:

Drew Noakes http://drewnoakes.com

See Also:
Serialized Form

Constructor Summary

Constructors
Constructor and Description

JpegSegmentData()

Constructors
Constructor and Description
`JpegSegmentData()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addSegment(byte segmentMarker, byte[] segmentBytes)` Adds segment bytes to the collection.
`boolean`	`containsSegment(byte segmentMarker)` Determines whether data is present for a given segment marker.
`static JpegSegmentData`	`fromFile(File file)` Deserialises the contents of a JpegSegmentData from a file.
`byte[]`	`getSegment(byte segmentMarker)` Gets the first Jpeg segment data for the specified marker.
`byte[]`	`getSegment(byte segmentMarker, int occurrence)` Gets segment data for a specific occurrence and marker.
`int`	`getSegmentCount(byte segmentMarker)` Returns the count of segment data byte arrays stored for a given segment marker.
`List<byte[]>`	`getSegmentList(byte segmentMarker)`
`Iterable<byte[]>`	`getSegments(byte segmentMarker)` Returns all instances of a given Jpeg segment.
`void`	`removeSegment(byte segmentMarker)` Removes all segments from the collection having the specified marker.
`void`	`removeSegmentOccurrence(byte segmentMarker, int occurrence)` Removes a specified instance of a segment's data from the collection.
`static void`	`toFile(File file, JpegSegmentData segmentData)` Serialises the contents of a JpegSegmentData to a file.

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

- Constructor Detail
  - JpegSegmentData
```
public JpegSegmentData()
```
- Method Detail
  - addSegment
```
public void addSegment(byte segmentMarker,
              byte[] segmentBytes)
```
    Adds segment bytes to the collection.
    
    Parameters:
    segmentMarker -
    segmentBytes -
  - getSegment
```
public byte[] getSegment(byte segmentMarker)
```
    Gets the first Jpeg segment data for the specified marker.
    
    Parameters:
    segmentMarker - the byte identifier for the desired segment
    
    Returns:
    a byte[] containing segment data or null if no data exists for that segment
  - getSegment
```
public byte[] getSegment(byte segmentMarker,
                int occurrence)
```
    Gets segment data for a specific occurrence and marker. Use this method when more than one occurrence of segment data for a given marker exists.
    
    Parameters:
    segmentMarker - identifies the required segment
    occurrence - the zero-based index of the occurrence
    
    Returns:
    the segment data as a byte[], or null if no segment exists for the marker & occurrence
  - getSegments
```
public Iterable<byte[]> getSegments(byte segmentMarker)
```
    Returns all instances of a given Jpeg segment. If no instances exist, an empty sequence is returned.
    
    Parameters:
    segmentMarker - a number which identifies the type of Jpeg segment being queried
    
    Returns:
    zero or more byte arrays, each holding the data of a Jpeg segment
  - getSegmentList
```
public List<byte[]> getSegmentList(byte segmentMarker)
```
  - getSegmentCount
```
public int getSegmentCount(byte segmentMarker)
```
    Returns the count of segment data byte arrays stored for a given segment marker.
    
    Parameters:
    segmentMarker - identifies the required segment
    
    Returns:
    the segment count (zero if no segments exist).
  - removeSegmentOccurrence
```
public void removeSegmentOccurrence(byte segmentMarker,
                           int occurrence)
```
    Removes a specified instance of a segment's data from the collection. Use this method when more than one occurrence of segment data for a given marker exists.
    
    Parameters:
    segmentMarker - identifies the required segment
    occurrence - the zero-based index of the segment occurrence to remove.
  - removeSegment
```
public void removeSegment(byte segmentMarker)
```
    Removes all segments from the collection having the specified marker.
    
    Parameters:
    segmentMarker - identifies the required segment
  - containsSegment
```
public boolean containsSegment(byte segmentMarker)
```
    Determines whether data is present for a given segment marker.
    
    Parameters:
    segmentMarker - identifies the required segment
    
    Returns:
    true if data exists, otherwise false
  - toFile
```
public static void toFile(File file,
          JpegSegmentData segmentData)
                   throws IOException
```
    Serialises the contents of a JpegSegmentData to a file.
    
    Parameters:
    file - to file to write from
    segmentData - the data to write
    
    Throws:
    
    IOException - if problems occur while writing
  - fromFile
```
public static JpegSegmentData fromFile(File file)
                                throws IOException,
                                       ClassNotFoundException
```
    Deserialises the contents of a JpegSegmentData from a file.
    
    Parameters:
    file - the file to read from
    
    Returns:
    the JpegSegmentData as read
    
    Throws:
    
    IOException - if problems occur while reading
    
    ClassNotFoundException - if problems occur while deserialising

Class JpegSegmentData

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

JpegSegmentData

Method Detail

addSegment

getSegment

getSegment

getSegments

getSegmentList

getSegmentCount

removeSegmentOccurrence

removeSegment

containsSegment

toFile

fromFile