Class ZipUtil
java.lang.Object
org.apache.commons.compress.archivers.zip.ZipUtil
Utility class for handling DOS and Java time conversions.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final byte[]
Smallest date/time ZIP can handle. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic long
adjustToLong
(int i) Assumes a negative integer really is a positive integer that has wrapped around and re-creates the original value.(package private) static long
bigToLong
(BigInteger big) Converts a BigInteger into a long, and blows up (NumberFormatException) if the BigInteger is too big.(package private) static boolean
Whether this library is able to read or write the given entry.(package private) static void
Checks whether the entry requires features not (yet) supported by the library and throws an exception if it does.(package private) static byte[]
copy
(byte[] from) Create a copy of the given array - or return null if the argument is null.(package private) static void
copy
(byte[] from, byte[] to, int offset) static long
dosToJavaTime
(long dosTime) Converts DOS time to Java time (number of milliseconds since epoch).static Date
fromDosTime
(ZipLong zipDosTime) Convert a DOS date/time field to a Date object.private static String
getUnicodeStringIfOriginalMatches
(AbstractUnicodeExtraField f, byte[] orig) If the stored CRC matches the one of the given name, return the Unicode name of the given field.(package private) static BigInteger
longToBig
(long l) Converts a long into a BigInteger.static byte[]
reverse
(byte[] array) Reverses a byte[] array.(package private) static void
setNameAndCommentFromExtraFields
(ZipArchiveEntry ze, byte[] originalNameBytes, byte[] commentBytes) If the entry has Unicode*ExtraFields and the CRCs of the names/comments match those of the extra fields, transfer the known Unicode values from the extra field.static int
signedByteToUnsignedInt
(byte b) Converts a signed byte into an unsigned integer representation (e.g., -1 becomes 255).private static boolean
Whether this library supports the encryption used by the given entry.private static boolean
supportsMethodOf
(ZipArchiveEntry entry) Whether this library supports the compression method used by the given entry.static byte[]
toDosTime
(long t) Convert a Date object to a DOS date/time field.static void
toDosTime
(long t, byte[] buf, int offset) Convert a Date object to a DOS date/time field.(package private) static void
static ZipLong
Convert a Date object to a DOS date/time field.static byte
unsignedIntToSignedByte
(int i) Converts an unsigned integer to a signed byte (e.g., 255 becomes -1).
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Field Details
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DOS_TIME_MIN
private static final byte[] DOS_TIME_MINSmallest date/time ZIP can handle.
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Constructor Details
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ZipUtil
public ZipUtil()
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Method Details
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toDosTime
Convert a Date object to a DOS date/time field.- Parameters:
time
- theDate
to convert- Returns:
- the date as a
ZipLong
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toDosTime
public static byte[] toDosTime(long t) Convert a Date object to a DOS date/time field.Stolen from InfoZip's
fileio.c
- Parameters:
t
- number of milliseconds since the epoch- Returns:
- the date as a byte array
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toDosTime
public static void toDosTime(long t, byte[] buf, int offset) Convert a Date object to a DOS date/time field.Stolen from InfoZip's
fileio.c
- Parameters:
t
- number of milliseconds since the epochbuf
- 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-4
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toDosTime
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adjustToLong
public static long adjustToLong(int i) Assumes a negative integer really is a positive integer that has wrapped around and re-creates the original value.- Parameters:
i
- the value to treat as unsigned int.- Returns:
- the unsigned int as a long.
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reverse
public static byte[] reverse(byte[] array) Reverses a byte[] array. Reverses in-place (thus provided array is mutated), but also returns same for convenience.- Parameters:
array
- to reverse (mutated in-place, but also returned for convenience).- Returns:
- the reversed array (mutated in-place, but also returned for convenience).
- Since:
- 1.5
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bigToLong
Converts a BigInteger into a long, and blows up (NumberFormatException) if the BigInteger is too big.- Parameters:
big
- BigInteger to convert.- Returns:
- long representation of the BigInteger.
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longToBig
Converts a long into a BigInteger. Negative numbers between -1 and -2^31 are treated as unsigned 32 bit (e.g., positive) integers. Negative numbers below -2^31 cause an IllegalArgumentException to be thrown.
- Parameters:
l
- long to convert to BigInteger.- Returns:
- BigInteger representation of the provided long.
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signedByteToUnsignedInt
public static int signedByteToUnsignedInt(byte b) Converts a signed byte into an unsigned integer representation (e.g., -1 becomes 255).- Parameters:
b
- byte to convert to int- Returns:
- int representation of the provided byte
- Since:
- 1.5
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unsignedIntToSignedByte
public static byte unsignedIntToSignedByte(int i) Converts an unsigned integer to a signed byte (e.g., 255 becomes -1).- Parameters:
i
- integer to convert to byte- Returns:
- byte representation of the provided int
- Throws:
IllegalArgumentException
- if the provided integer is not inside the range [0,255].- Since:
- 1.5
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fromDosTime
Convert a DOS date/time field to a Date object.- Parameters:
zipDosTime
- contains the stored DOS time.- Returns:
- a Date instance corresponding to the given time.
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dosToJavaTime
public static long dosToJavaTime(long dosTime) Converts DOS time to Java time (number of milliseconds since epoch).- Parameters:
dosTime
- time to convert- Returns:
- converted time
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setNameAndCommentFromExtraFields
static void setNameAndCommentFromExtraFields(ZipArchiveEntry ze, byte[] originalNameBytes, byte[] commentBytes) If the entry has Unicode*ExtraFields and the CRCs of the names/comments match those of the extra fields, transfer the known Unicode values from the extra field. -
getUnicodeStringIfOriginalMatches
If the stored CRC matches the one of the given name, return the Unicode name of the given field.If the field is null or the CRCs don't match, return null instead.
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copy
static byte[] copy(byte[] from) Create a copy of the given array - or return null if the argument is null. -
copy
static void copy(byte[] from, byte[] to, int offset) -
canHandleEntryData
Whether this library is able to read or write the given entry. -
supportsEncryptionOf
Whether this library supports the encryption used by the given entry.- Returns:
- true if the entry isn't encrypted at all
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supportsMethodOf
Whether this library supports the compression method used by the given entry.- Returns:
- true if the compression method is supported
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checkRequestedFeatures
Checks whether the entry requires features not (yet) supported by the library and throws an exception if it does.- Throws:
UnsupportedZipFeatureException
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