程序包 java.security

类 DigestOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.security.DigestOutputStream

所有已实现的接口:

Closeable, Flushable, AutoCloseable

public class DigestOutputStream
extends FilterOutputStream

A transparent stream that updates the associated message digest using the bits going through the stream.

To complete the message digest computation, call one of the digest methods on the associated message digest after your calls to one of this digest output stream's write methods.

It is possible to turn this stream on or off (see on). When it is on, a call to one of the write methods results in an update on the message digest. But when it is off, the message digest is not updated. The default is for the stream to be on.

另请参阅:

MessageDigest, DigestInputStream

字段概要

字段

限定符和类型	字段	说明
protected MessageDigest	digest	The message digest associated with this stream.

从类继承的字段 java.io.FilterOutputStream

out

构造器概要

构造器

构造器	说明
DigestOutputStream(OutputStream stream, MessageDigest digest)	Creates a digest output stream, using the specified output stream and message digest.

方法概要

限定符和类型	方法	说明
MessageDigest	getMessageDigest()	Returns the message digest associated with this stream.
void	on(boolean on)	Turns the digest function on or off.
void	setMessageDigest(MessageDigest digest)	Associates the specified message digest with this stream.
String	toString()	Prints a string representation of this digest output stream and its associated message digest object.
void	write(byte[] b, int off, int len)	Updates the message digest (if the digest function is on) using the specified subarray, and in any case writes the subarray to the output stream.
void	write(int b)	Updates the message digest (if the digest function is on) using the specified byte, and in any case writes the byte to the output stream.

从类继承的方法 java.io.FilterOutputStream

close, flush, write

从类继承的方法 java.lang.Object

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

字段详细资料

digest

protected MessageDigest digest

The message digest associated with this stream.

构造器详细资料

DigestOutputStream

public DigestOutputStream(OutputStream stream,
                          MessageDigest digest)

Creates a digest output stream, using the specified output stream and message digest.

参数:

stream - the output stream.

digest - the message digest to associate with this stream.

方法详细资料

getMessageDigest

public MessageDigest getMessageDigest()

Returns the message digest associated with this stream.

返回:

the message digest associated with this stream.

另请参阅:

setMessageDigest(java.security.MessageDigest)

setMessageDigest

public void setMessageDigest(MessageDigest digest)

Associates the specified message digest with this stream.

参数:

digest - the message digest to be associated with this stream.

另请参阅:

getMessageDigest()

write

public void write(int b)
           throws IOException

Updates the message digest (if the digest function is on) using the specified byte, and in any case writes the byte to the output stream. That is, if the digest function is on (see on), this method calls update on the message digest associated with this stream, passing it the byte b. This method then writes the byte to the output stream, blocking until the byte is actually written.

覆盖:

write 在类中 FilterOutputStream

参数:

b - the byte to be used for updating and writing to the output stream.

抛出:

IOException - if an I/O error occurs.

另请参阅:

MessageDigest.update(byte)

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Updates the message digest (if the digest function is on) using the specified subarray, and in any case writes the subarray to the output stream. That is, if the digest function is on (see on), this method calls update on the message digest associated with this stream, passing it the subarray specifications. This method then writes the subarray bytes to the output stream, blocking until the bytes are actually written.

覆盖:

write 在类中 FilterOutputStream

参数:

b - the array containing the subarray to be used for updating and writing to the output stream.

off - the offset into b of the first byte to be updated and written.

len - the number of bytes of data to be updated and written from b, starting at offset off.

抛出:

IOException - if an I/O error occurs.

另请参阅:

MessageDigest.update(byte[], int, int)

on

public void on(boolean on)

Turns the digest function on or off. The default is on. When it is on, a call to one of the write methods results in an update on the message digest. But when it is off, the message digest is not updated.

参数:

on - true to turn the digest function on, false to turn it off.

toString

public String toString()

Prints a string representation of this digest output stream and its associated message digest object.

覆盖:

toString 在类中 Object

返回:

a string representation of the object.