com.tencent.cos.xml.crypto

类 ResettableInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

com.tencent.cos.xml.crypto.SdkFilterInputStream

com.tencent.cos.xml.crypto.ReleasableInputStream

com.tencent.cos.xml.crypto.ResettableInputStream

所有已实现的接口:

Releasable, java.io.Closeable, java.lang.AutoCloseable

public class ResettableInputStream
extends ReleasableInputStream

A mark-and-resettable input stream that can be used on files or file input streams. In particular, a ResettableInputStream allows the close operation to be disabled via ReleasableInputStream.disableClose() (to avoid accidentally being closed). This is necessary when such input stream needs to be marked-and-reset multiple times but only as long as the stream has not been closed.

The creator of this input stream should therefore always call ReleasableInputStream.release() in a finally block to truly release the underlying resources.

另请参阅:

Releasable

字段概要

从类继承的字段 java.io.FilterInputStream

in

构造器概要

构造器

构造器和说明
ResettableInputStream(java.io.File file)
ResettableInputStream(java.io.FileInputStream fis)
ResettableInputStream(java.lang.String filePath)

方法概要

限定符和类型	方法和说明
int	available() Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
java.io.File	getFile() Returns the underlying file, if known; or null if not;
void	mark(int limit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
static ResettableInputStream	newResettableInputStream(java.io.File file) Convenient factory method to construct a new resettable input stream for the given file, converting any IOException into CosClientException.
static ResettableInputStream	newResettableInputStream(java.io.FileInputStream fis) Convenient factory method to construct a new resettable input stream for the given file input stream, converting any IOException into CosClientException.
static ResettableInputStream	newResettableInputStream(java.io.FileInputStream fis, java.lang.String errmsg) Convenient factory method to construct a new resettable input stream for the given file input stream, converting any IOException into CosClientException with the given error message.
static ResettableInputStream	newResettableInputStream(java.io.File file, java.lang.String errmsg) Convenient factory method to construct a new resettable input stream for the given file, converting any IOException into CosClientException with the given error message.
int	read() Reads the next byte of data from this input stream.
int	read(byte[] arg0, int arg1, int arg2) Reads up to len bytes of data from this input stream into an array of bytes.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n) Skips over and discards n bytes of data from the input stream.

从类继承的方法 com.tencent.cos.xml.crypto.ReleasableInputStream

close, disableClose, isCloseDisabled, release, wrap

从类继承的方法 com.tencent.cos.xml.crypto.SdkFilterInputStream

abort, abortIfNeeded, isAborted

从类继承的方法 java.io.FilterInputStream

read

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

ResettableInputStream

public ResettableInputStream(java.io.File file)
                      throws java.io.IOException

参数:

file - must not be null. Upon successful construction the the file will be opened with an input stream automatically marked at the starting position of the given file.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

抛出:

java.io.IOException

ResettableInputStream

public ResettableInputStream(java.lang.String filePath)
                      throws java.io.IOException

抛出:

java.io.IOException

ResettableInputStream

public ResettableInputStream(java.io.FileInputStream fis)
                      throws java.io.IOException

参数:

fis - file input stream; must not be null. Upon successful construction the input stream will be automatically marked at the current position of the given file input stream.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

抛出:

java.io.IOException

方法详细资料

markSupported

public final boolean markSupported()

从类复制的说明: java.io.FilterInputStream

Tests if this input stream supports the mark and reset methods. This method simply performs in.markSupported().

覆盖:

markSupported 在类中 SdkFilterInputStream

返回:

true if this stream type supports the mark and reset method; false otherwise.

另请参阅:

FilterInputStream.in, InputStream.mark(int), InputStream.reset()

mark

public void mark(int limit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes. This method works as long as the underlying file has not been closed.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames.

In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

覆盖:

mark 在类中 SdkFilterInputStream

参数:

limit - limit

另请参阅:

FilterInputStream.in, FilterInputStream.reset()

reset

public void reset()
           throws java.io.IOException

Repositions this stream to the position at the time the mark method was last called on this input stream. This method works as long as the underlying file has not been closed.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

覆盖:

reset 在类中 SdkFilterInputStream

抛出:

java.io.IOException - if the stream has not been marked or if the mark has been invalidated.

另请参阅:

FilterInputStream.in, FilterInputStream.mark(int)

available

public int available()
              throws java.io.IOException

从类复制的说明: java.io.FilterInputStream

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream. The next caller might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

This method returns the result of in.available().

覆盖:

available 在类中 SdkFilterInputStream

返回:

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking.

抛出:

java.io.IOException - if an I/O error occurs.

read

public int read()
         throws java.io.IOException

从类复制的说明: java.io.FilterInputStream

Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

This method simply performs in.read() and returns the result.

覆盖:

read 在类中 SdkFilterInputStream

返回:

the next byte of data, or -1 if the end of the stream is reached.

抛出:

java.io.IOException - if an I/O error occurs.

另请参阅:

FilterInputStream.in

skip

public long skip(long n)
          throws java.io.IOException

从类复制的说明: java.io.FilterInputStream

Skips over and discards n bytes of data from the input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. The actual number of bytes skipped is returned.

This method simply performs in.skip(n).

覆盖:

skip 在类中 SdkFilterInputStream

参数:

n - the number of bytes to be skipped.

返回:

the actual number of bytes skipped.

抛出:

java.io.IOException - if the stream does not support seek, or if some other I/O error occurs.

read

public int read(byte[] arg0,
                int arg1,
                int arg2)
         throws java.io.IOException

从类复制的说明: java.io.FilterInputStream

Reads up to len bytes of data from this input stream into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned.

This method simply performs in.read(b, off, len) and returns the result.

覆盖:

read 在类中 SdkFilterInputStream

参数:

arg0 - the buffer into which the data is read.

arg1 - the start offset in the destination array b

arg2 - the maximum number of bytes read.

返回:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

抛出:

java.io.IOException - if an I/O error occurs.

另请参阅:

FilterInputStream.in

getFile

public java.io.File getFile()

Returns the underlying file, if known; or null if not;

newResettableInputStream

public static ResettableInputStream newResettableInputStream(java.io.File file)

Convenient factory method to construct a new resettable input stream for the given file, converting any IOException into CosClientException.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

newResettableInputStream

public static ResettableInputStream newResettableInputStream(java.io.File file,
                                                             java.lang.String errmsg)

Convenient factory method to construct a new resettable input stream for the given file, converting any IOException into CosClientException with the given error message.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

newResettableInputStream

public static ResettableInputStream newResettableInputStream(java.io.FileInputStream fis)

Convenient factory method to construct a new resettable input stream for the given file input stream, converting any IOException into CosClientException.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.

newResettableInputStream

public static ResettableInputStream newResettableInputStream(java.io.FileInputStream fis,
                                                             java.lang.String errmsg)

Convenient factory method to construct a new resettable input stream for the given file input stream, converting any IOException into CosClientException with the given error message.

Note the creation of a ResettableInputStream would entail physically opening a file. If the opened file is meant to be closed only (in a finally block) by the very same code block that created it, then it is necessary that the release method must not be called while the execution is made in other stack frames. In such case, as other stack frames may inadvertently or indirectly call the close method of the stream, the creator of the stream would need to explicitly disable the accidental closing via ReleasableInputStream.disableClose(), so that the release method becomes the only way to truly close the opened file.