Class GeneralPurposeBit
java.lang.Object
org.apache.commons.compress.archivers.zip.GeneralPurposeBit
- All Implemented Interfaces:
Cloneable
Parser/encoder for the "general purpose bit" field in ZIP's local
file and central directory headers.
- Since:
- 1.1
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int
Indicates that a data descriptor stored after the file contents will hold CRC and size information.private boolean
private static final int
Indicates that the file is encrypted.private boolean
private boolean
private static final int
Indicates the number of Shannon-Fano trees used by the compression method 6 (imploding).private int
private static final int
Indicates the size of the sliding dictionary used by the compression method 6 (imploding).private int
private static final int
Indicates strong encryption.private boolean
static final int
Indicates that file names are written in UTF-8. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionclone()
byte[]
encode()
Encodes the set bits in a form suitable for ZIP archives.void
encode
(byte[] buf, int offset) Encodes the set bits in a form suitable for ZIP archives.boolean
(package private) int
Returns the number of trees used by the compression method 6 (imploding).(package private) int
Returns the sliding dictionary size used by the compression method 6 (imploding).int
hashCode()
static GeneralPurposeBit
parse
(byte[] data, int offset) Parses the supported flags from the given archive data.void
useDataDescriptor
(boolean b) whether the current entry will use the data descriptor to store CRC and size information.void
useEncryption
(boolean b) whether the current entry will be encrypted.boolean
whether the current entry uses the data descriptor to store CRC and size information.boolean
whether the current entry is encrypted.boolean
whether the current entry is encrypted using strong encryption.void
useStrongEncryption
(boolean b) whether the current entry will be encrypted using strong encryption.boolean
whether the current entry uses UTF8 for file name and comment.void
useUTF8ForNames
(boolean b) whether the current entry will use UTF8 for file name and comment.
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Field Details
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ENCRYPTION_FLAG
private static final int ENCRYPTION_FLAGIndicates that the file is encrypted.- See Also:
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SLIDING_DICTIONARY_SIZE_FLAG
private static final int SLIDING_DICTIONARY_SIZE_FLAGIndicates the size of the sliding dictionary used by the compression method 6 (imploding).- 0: 4096 bytes
- 1: 8192 bytes
- See Also:
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NUMBER_OF_SHANNON_FANO_TREES_FLAG
private static final int NUMBER_OF_SHANNON_FANO_TREES_FLAGIndicates the number of Shannon-Fano trees used by the compression method 6 (imploding).- 0: 2 trees (lengths, distances)
- 1: 3 trees (literals, lengths, distances)
- See Also:
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DATA_DESCRIPTOR_FLAG
private static final int DATA_DESCRIPTOR_FLAGIndicates that a data descriptor stored after the file contents will hold CRC and size information.- See Also:
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STRONG_ENCRYPTION_FLAG
private static final int STRONG_ENCRYPTION_FLAGIndicates strong encryption.- See Also:
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UFT8_NAMES_FLAG
public static final int UFT8_NAMES_FLAGIndicates that file names are written in UTF-8.The only reason this is public is that
ZipArchiveOutputStream.EFS_FLAG
was public in Apache Commons Compress 1.0 and we needed a substitute for it.- See Also:
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languageEncodingFlag
private boolean languageEncodingFlag -
dataDescriptorFlag
private boolean dataDescriptorFlag -
encryptionFlag
private boolean encryptionFlag -
strongEncryptionFlag
private boolean strongEncryptionFlag -
slidingDictionarySize
private int slidingDictionarySize -
numberOfShannonFanoTrees
private int numberOfShannonFanoTrees
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Constructor Details
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GeneralPurposeBit
public GeneralPurposeBit()
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Method Details
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usesUTF8ForNames
public boolean usesUTF8ForNames()whether the current entry uses UTF8 for file name and comment.- Returns:
- whether the current entry uses UTF8 for file name and comment.
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useUTF8ForNames
public void useUTF8ForNames(boolean b) whether the current entry will use UTF8 for file name and comment.- Parameters:
b
- whether the current entry will use UTF8 for file name and comment.
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usesDataDescriptor
public boolean usesDataDescriptor()whether the current entry uses the data descriptor to store CRC and size information.- Returns:
- whether the current entry uses the data descriptor to store CRC and size information
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useDataDescriptor
public void useDataDescriptor(boolean b) whether the current entry will use the data descriptor to store CRC and size information.- Parameters:
b
- whether the current entry will use the data descriptor to store CRC and size information
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usesEncryption
public boolean usesEncryption()whether the current entry is encrypted.- Returns:
- whether the current entry is encrypted
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useEncryption
public void useEncryption(boolean b) whether the current entry will be encrypted.- Parameters:
b
- whether the current entry will be encrypted
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usesStrongEncryption
public boolean usesStrongEncryption()whether the current entry is encrypted using strong encryption.- Returns:
- whether the current entry is encrypted using strong encryption
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useStrongEncryption
public void useStrongEncryption(boolean b) whether the current entry will be encrypted using strong encryption.- Parameters:
b
- whether the current entry will be encrypted using strong encryption
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getSlidingDictionarySize
int getSlidingDictionarySize()Returns the sliding dictionary size used by the compression method 6 (imploding). -
getNumberOfShannonFanoTrees
int getNumberOfShannonFanoTrees()Returns the number of trees used by the compression method 6 (imploding). -
encode
public byte[] encode()Encodes the set bits in a form suitable for ZIP archives.- Returns:
- the encoded general purpose bits
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encode
public void encode(byte[] buf, int offset) Encodes the set bits in a form suitable for ZIP archives.- Parameters:
buf
- the output bufferoffset
- The offset within the output buffer of the first byte to be written. must be non-negative and no larger thanbuf.length-2
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parse
Parses the supported flags from the given archive data.- Parameters:
data
- local file header or a central directory entry.offset
- offset at which the general purpose bit starts- Returns:
- parsed flags
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hashCode
public int hashCode() -
equals
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clone
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