Class CheckedInputStream

java.util.zip.CheckedInputStream

All Implemented Interfaces:: Closeable, AutoCloseable

public class CheckedInputStream extends FilterInputStream

An input stream that also maintains a checksum of the data being read. The checksum can then be used to verify the integrity of the input data.

Since:

1.1

See Also:

Field Summary

Fields declared in class FilterInputStream

in

Modifier and Type	Field	Description
`protected InputStream`	`in`	The input stream to be filtered.

Constructor Summary

Constructor	Description
`CheckedInputStream(InputStream in, Checksum cksum)`	Creates an input stream using the specified Checksum.

Method Summary

Modifier and Type	Method	Description
`Checksum`	`getChecksum()`	Returns the Checksum for this input stream.
`int`	`read()`	Reads a byte.
`int`	`read(byte[] buf, int off, int len)`	Reads into an array of bytes.
`long`	`skip(long n)`	Skips specified number of bytes of input.

Methods declared in class FilterInputStream

available, close, mark, markSupported, read, reset

Modifier and Type	Method	Description
`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.
`void`	`close()`	Closes this input stream and releases any system resources associated with the stream.
`void`	`mark(int readlimit)`	Marks the current position in this input stream.
`boolean`	`markSupported()`	Tests if this input stream supports the `mark` and `reset` methods.
`int`	`read(byte[] b)`	Reads up to `b.length` 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.

Methods declared in class InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Modifier and Type	Method	Description
`static InputStream`	`nullInputStream()`	Returns a new `InputStream` that reads no bytes.
`byte[]`	`readAllBytes()`	Reads all remaining bytes from the input stream.
`int`	`readNBytes(byte[] b, int off, int len)`	Reads the requested number of bytes from the input stream into the given byte array.
`byte[]`	`readNBytes(int len)`	Reads up to a specified number of bytes from the input stream.
`void`	`skipNBytes(long n)`	Skips over and discards exactly `n` bytes of data from this input stream.
`long`	`transferTo(OutputStream out)`	Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

Methods declared in class Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

CheckedInputStream

public CheckedInputStream(InputStream in, Checksum cksum)

Creates an input stream using the specified Checksum.

Parameters:: in - the input stream; cksum - the Checksum

Method Details

read

public int read() throws IOException

Reads a byte. Will block if no input is available.

Overrides:

read in class FilterInputStream

Returns:

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

Throws:

IOException - if an I/O error has occurred

See Also:

read

public int read(byte[] buf, int off, int len) throws IOException

Reads 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.

Overrides:

read in class FilterInputStream

Parameters:

buf - the buffer into which the data is read

off - the start offset in the destination array b

len - the maximum number of bytes read

Returns:

the actual number of bytes read, or -1 if the end of the stream is reached.

Throws:

NullPointerException - If buf is null.

IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than buf.length - off

IOException - if an I/O error has occurred

See Also:

skip

public long skip(long n) throws IOException

Skips specified number of bytes of input.

Overrides:

skip in class FilterInputStream

Parameters:

n - the number of bytes to skip

Returns:

the actual number of bytes skipped

Throws:

IOException - if an I/O error has occurred

See Also:

getChecksum

public Checksum getChecksum()

Returns the Checksum for this input stream.

Returns:: the Checksum value

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.