com.tencent.kona.sun.security.util

Class IOUtils

java.lang.Object

com.tencent.kona.sun.security.util.IOUtils

public class IOUtils
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
IOUtils()

Method Summary

Modifier and Type	Method and Description
static byte[]	readAllBytes(java.io.InputStream is) Reads all remaining bytes from the input stream.
static byte[]	readExactlyNBytes(java.io.InputStream is, int length) Read exactly length of bytes from in.
static byte[]	readFully(java.io.InputStream is, int length, boolean readAll) Compatibility wrapper for third party users of sun.misc.IOUtils.readFully following its removal in JDK-8231139.
static int	readNBytes(java.io.InputStream is, byte[] b, int off, int len) Reads the requested number of bytes from the input stream into the given byte array.
static byte[]	readNBytes(java.io.InputStream is, int len) Reads up to a specified number of bytes from the input stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

IOUtils

public IOUtils()

Method Detail

readExactlyNBytes

public static byte[] readExactlyNBytes(java.io.InputStream is,
                                       int length)
                                throws java.io.IOException

Read exactly length of bytes from in.

Note that this method is safe to be called with unknown large length argument. The memory used is proportional to the actual bytes available. An exception is thrown if there are not enough bytes in the stream.

Parameters:

is - input stream, must not be null

length - number of bytes to read

Returns:

bytes read

Throws:

java.io.EOFException - if there are not enough bytes in the stream

java.io.IOException - if an I/O error occurs or length is negative

java.lang.OutOfMemoryError - if an array of the required size cannot be allocated.

readAllBytes

public static byte[] readAllBytes(java.io.InputStream is)
                           throws java.io.IOException

Reads all remaining bytes from the input stream. This method blocks until all remaining bytes have been read and end of stream is detected, or an exception is thrown. This method does not close the input stream.

When this stream reaches end of stream, further invocations of this method will return an empty byte array.

Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Parameters:

is - input stream, must not be null

Returns:

a byte array containing the bytes read from this input stream

Throws:

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

java.lang.OutOfMemoryError - if an array of the required size cannot be allocated.

Since:

1.9

readNBytes

public static byte[] readNBytes(java.io.InputStream is,
                                int len)
                         throws java.io.IOException

Reads up to a specified number of bytes from the input stream. This method blocks until the requested number of bytes have been read, end of stream is detected, or an exception is thrown. This method does not close the input stream.

The length of the returned array equals the number of bytes read from the stream. If len is zero, then no bytes are read and an empty byte array is returned. Otherwise, up to len bytes are read from the stream. Fewer than len bytes may be read if end of stream is encountered.

When this stream reaches end of stream, further invocations of this method will return an empty byte array.

Note that this method is intended for simple cases where it is convenient to read the specified number of bytes into a byte array. The total amount of memory allocated by this method is proportional to the number of bytes read from the stream which is bounded by len. Therefore, the method may be safely called with very large values of len provided sufficient memory is available.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Parameters:

is - input stream, must not be null

len - the maximum number of bytes to read

Returns:

a byte array containing the bytes read from this input stream

Throws:

java.lang.IllegalArgumentException - if length is negative

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

java.lang.OutOfMemoryError - if an array of the required size cannot be allocated.

Since:

11

readNBytes

public static int readNBytes(java.io.InputStream is,
                             byte[] b,
                             int off,
                             int len)
                      throws java.io.IOException

Reads the requested number of bytes from the input stream into the given byte array. This method blocks until len bytes of input data have been read, end of stream is detected, or an exception is thrown. The number of bytes actually read, possibly zero, is returned. This method does not close the input stream.

In the case where end of stream is reached before len bytes have been read, then the actual number of bytes read will be returned. When this stream reaches end of stream, further invocations of this method will return zero.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read up to len bytes.

The first byte read is stored into element b[off], the next one in to b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k ] through b[off+len-1] unaffected.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes of b have been updated with data from the input stream. Consequently the input stream and b may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Parameters:

is - input stream, must not be null

b - the byte array into which the data is read

off - the start offset in b at which the data is written

len - the maximum number of bytes to read

Returns:

the actual number of bytes read into the buffer

Throws:

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

java.lang.NullPointerException - if b is null

java.lang.IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off

Since:

1.9

readFully

public static byte[] readFully(java.io.InputStream is,
                               int length,
                               boolean readAll)
                        throws java.io.IOException

Compatibility wrapper for third party users of sun.misc.IOUtils.readFully following its removal in JDK-8231139. Read up to length of bytes from in until EOF is detected.

Parameters:

is - input stream, must not be null

length - number of bytes to read

readAll - if true, an EOFException will be thrown if not enough bytes are read.

Returns:

bytes read

Throws:

java.io.EOFException - if there are not enough bytes in the stream

java.io.IOException - if an I/O error occurs or length is negative

java.lang.OutOfMemoryError - if an array of the required size cannot be allocated.