CheckedInputStream

The CheckedInputStream class is used to maintain a checksum at the same time as the data, on which the checksum is computed, is read from a stream. The purpose of this checksum is to establish data integrity, comparing the computed checksum against a published checksum value.

Summary

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Inherited Fields

From class java.io.FilterInputStream

Public Constructors
	CheckedInputStream(InputStream is, Checksum csum) Constructs a new `CheckedInputStream` on `InputStream` `is`.

Public Constructors

CheckedInputStream(InputStream is, Checksum csum)

Constructs a new CheckedInputStream on InputStream is.

Public Methods
Checksum	getChecksum() Returns the checksum calculated on the stream read so far.
int	read() Reads one byte of data from the underlying input stream and updates the checksum with the byte data.
int	read(byte[] buffer, int byteOffset, int byteCount) Reads up to `byteCount` bytes of data from the underlying input stream, storing it into `buffer`, starting at offset `byteOffset`.
long	skip(long byteCount) Skip up to `byteCount` bytes of data on the underlying input stream.

Public Methods

Checksum

getChecksum()

Returns the checksum calculated on the stream read so far.

int

read()

Reads one byte of data from the underlying input stream and updates the checksum with the byte data.

int

read(byte[] buffer, int byteOffset, int byteCount)

Reads up to byteCount bytes of data from the underlying input stream, storing it into buffer, starting at offset byteOffset.

long

skip(long byteCount)

Skip up to byteCount bytes of data on the underlying input stream.

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Inherited Methods

From class java.io.FilterInputStream

From class java.io.InputStream

int	available() Returns an estimated number of bytes that can be read or skipped without blocking for more input.
void	close() Closes this stream.
void	mark(int readlimit) Sets a mark position in this InputStream.
boolean	markSupported() Indicates whether this stream supports the `mark()` and `reset()` methods.
int	read(byte[] buffer) Equivalent to `read(buffer, 0, buffer.length)`.
abstract int	read() Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
int	read(byte[] buffer, int byteOffset, int byteCount) Reads up to `byteCount` bytes from this stream and stores them in the byte array `buffer` starting at `byteOffset`.
synchronized void	reset() Resets this stream to the last marked location.
long	skip(long byteCount) Skips at most `byteCount` bytes in this stream.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface java.io.Closeable

From interface java.lang.AutoCloseable

Public Constructors

public CheckedInputStream (InputStream is, Checksum csum)

Added in API level 1

Constructs a new CheckedInputStream on InputStream is. The checksum will be calculated using the algorithm implemented by csum.

Warning: passing a null source creates an invalid CheckedInputStream. All operations on such a stream will fail.

Parameters

is	the input stream to calculate checksum from.
csum	an entity implementing the checksum algorithm.

Public Methods

public Checksum getChecksum ()

Added in API level 1

Returns the checksum calculated on the stream read so far.

public int read ()

Added in API level 1

Reads one byte of data from the underlying input stream and updates the checksum with the byte data.

Returns

-1 at the end of the stream, a single byte value otherwise.

Throws

IOException	if an `IOException` occurs.

public int read (byte[] buffer, int byteOffset, int byteCount)

Added in API level 1

Reads up to byteCount bytes of data from the underlying input stream, storing it into buffer, starting at offset byteOffset. The checksum is updated with the bytes read. Returns the number of bytes actually read or -1 if arrived at the end of the filtered stream while reading the data.

Throws

IOException	if this stream is closed or some I/O error occurs.

public long skip (long byteCount)

Added in API level 1

Skip up to byteCount bytes of data on the underlying input stream. Any skipped bytes are added to the running checksum value.

Parameters

byteCount	the number of bytes to skip.

Returns

the number of bytes skipped.

Throws

IOException	if this stream is closed or another I/O error occurs.

java.lang.Object
↳	java.io.InputStream
	↳	java.io.FilterInputStream
		↳	java.util.zip.CheckedInputStream

Results

Interfaces

Classes

Exceptions

Errors

Class Overview

Summary

Public Constructors

public CheckedInputStream (InputStream is, Checksum csum)

Parameters

Public Methods

public Checksum getChecksum ()

public int read ()

Returns

Throws

public int read (byte[] buffer, int byteOffset, int byteCount)

Throws

public long skip (long byteCount)

Parameters

Returns

Throws