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Top Description Fields Constructors Methods
jdk.internal.jimage

public final Class ImageHeader

extends Object
Class Inheritance
Imports
java.nio.ByteBuffer, .IntBuffer, java.util.Objects
Defines the header and version information for jimage files.

Version number changes must be synced in a single change across all code which reads/writes jimage files, and code which tries to open a jimage file with an unexpected version should fail.

Known jimage file code which needs updating on version change:

Version history:

Implementation Note

This class needs to maintain JDK 8 source compatibility. It is used internally in the JDK to implement jimage/jrtfs access, but also compiled and delivered as part of the jrtfs.jar to support access to the jimage file provided by the shipped JDK by tools running on JDK 8.

Field Summary

Modifier and TypeField and Description
private final int
flags

private static final int
HEADER_SLOTS

private final int
locationsSize

public static final int
MAGIC

private final int
magic

public static final int
MAJOR_VERSION

private final int
majorVersion

public static final int
MINOR_VERSION

private final int
minorVersion

private final int
resourceCount

private final int
stringsSize

private final int
tableLength

Constructor Summary

AccessConstructor and Description
public
ImageHeader(int resourceCount, int tableCount, int locationsSize, int stringsSize)

public
ImageHeader(int magic, int majorVersion, int minorVersion, int flags, int resourceCount, int tableLength, int locationsSize, int stringsSize)

Method Summary

Modifier and TypeMethod and Description
public int
getFlags()

public static int
getHeaderSize()

public int
getIndexSize()

pack-priv int
getLocationsOffset()

public int
getLocationsSize()

public int
getMagic()

public int
getMajorVersion()

public int
getMinorVersion()

pack-priv int
getOffsetsOffset()

public int
getOffsetsSize()

pack-priv int
getRedirectOffset()

public int
getRedirectSize()

public int
getResourceCount()

pack-priv int
getStringsOffset()

public int
getStringsSize()

public int
getTableLength()

pack-priv static ImageHeader
readFrom(IntBuffer buffer)

public void
writeTo(ImageStream stream)

public void
writeTo(ByteBuffer buffer)

Inherited from java.lang.Object:
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Field Detail

flagsback to summary
private final int flags
HEADER_SLOTSback to summary
private static final int HEADER_SLOTS
locationsSizeback to summary
private final int locationsSize
MAGICback to summary
public static final int MAGIC
magicback to summary
private final int magic
MAJOR_VERSIONback to summary
public static final int MAJOR_VERSION
majorVersionback to summary
private final int majorVersion
MINOR_VERSIONback to summary
public static final int MINOR_VERSION
minorVersionback to summary
private final int minorVersion
resourceCountback to summary
private final int resourceCount
stringsSizeback to summary
private final int stringsSize
tableLengthback to summary
private final int tableLength

Constructor Detail

ImageHeaderback to summary
public ImageHeader(int resourceCount, int tableCount, int locationsSize, int stringsSize)
ImageHeaderback to summary
public ImageHeader(int magic, int majorVersion, int minorVersion, int flags, int resourceCount, int tableLength, int locationsSize, int stringsSize)

Method Detail

getFlagsback to summary
public int getFlags()
getHeaderSizeback to summary
public static int getHeaderSize()
getIndexSizeback to summary
public int getIndexSize()
getLocationsOffsetback to summary
pack-priv int getLocationsOffset()
getLocationsSizeback to summary
public int getLocationsSize()
getMagicback to summary
public int getMagic()
getMajorVersionback to summary
public int getMajorVersion()
getMinorVersionback to summary
public int getMinorVersion()
getOffsetsOffsetback to summary
pack-priv int getOffsetsOffset()
getOffsetsSizeback to summary
public int getOffsetsSize()
getRedirectOffsetback to summary
pack-priv int getRedirectOffset()
getRedirectSizeback to summary
public int getRedirectSize()
getResourceCountback to summary
public int getResourceCount()
getStringsOffsetback to summary
pack-priv int getStringsOffset()
getStringsSizeback to summary
public int getStringsSize()
getTableLengthback to summary
public int getTableLength()
readFromback to summary
pack-priv static ImageHeader readFrom(IntBuffer buffer)
writeToback to summary
public void writeTo(ImageStream stream)
writeToback to summary
public void writeTo(ByteBuffer buffer)