public final class IOUtils extends Object
This class provides static utility methods for input/output operations.
The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case, one that uses the platform default encoding and the other which allows you to specify an encoding. You are encouraged to always specify an encoding because relying on the platform default can lead to unexpected results, for example when moving from development to production.
All the methods in this class that read a stream are buffered internally.
This means that there is no cause to use a BufferedInputStream
or BufferedReader
. The default buffer size of 4K has been shown
to be efficient in tests.
Wherever possible, the methods in this class do not flush or close the stream. This is to avoid making non-portable assumptions about the streams' origin and further use. Thus the caller is still responsible for closing streams after use.
Origin of code: Excalibur.
Modifier and Type | Field and Description |
---|---|
static String |
LINE_SEPARATOR
The system line separator string.
|
Modifier and Type | Method and Description |
---|---|
static int |
copy(InputStream input,
OutputStream output)
Copies bytes from an
InputStream to an
OutputStream . |
static void |
copy(InputStream input,
Writer output)
Copy bytes from an
InputStream to chars on a
Writer using the default character encoding of the platform. |
static int |
copy(Reader input,
Writer output)
Copy chars from a
Reader to a Writer . |
static long |
copyLarge(InputStream input,
OutputStream output)
Copies bytes from a large (over 2GB)
InputStream to an
OutputStream . |
static long |
copyLarge(Reader input,
Writer output)
Copy chars from a large (over 2GB)
Reader to a Writer . |
static byte[] |
toByteArray(InputStream input)
Get the contents of an
InputStream as a ByteArray |
static String |
toString(InputStream input)
Get the contents of an
InputStream as a String
using the default character encoding of the platform. |
public static final String LINE_SEPARATOR
public static String toString(InputStream input) throws IOException
InputStream
as a String
using the default character encoding of the platform.
This method buffers the input internally, so there is no need to use a
BufferedInputStream
.
input
- the InputStream
to read fromNullPointerException
- if the input is nullIOException
- if an I/O error occurspublic static byte[] toByteArray(InputStream input) throws IOException
InputStream
as a ByteArray
This method buffers the input internally, so there is no need to use a
BufferedInputStream
.
input
- the InputStream
to read fromNullPointerException
- if the input is nullIOException
- if an I/O error occurspublic static int copy(InputStream input, OutputStream output) throws IOException
InputStream
to an
OutputStream
.
This method buffers the input internally, so there is no need to use a
BufferedInputStream
.
Large streams (over 2GB) will return a bytes copied value of
-1
after the copy has completed since the correct
number of bytes cannot be returned as an int. For large streams
use the copyLarge(InputStream, OutputStream)
method.
input
- the InputStream
to read fromoutput
- the OutputStream
to write toNullPointerException
- if the input or output is nullIOException
- if an I/O error occurspublic static long copyLarge(InputStream input, OutputStream output) throws IOException
InputStream
to an
OutputStream
.
This method uses the provided buffer, so there is no need to use a
BufferedInputStream
.
input
- the InputStream
to read fromoutput
- the OutputStream
to write toNullPointerException
- if the input or output is nullIOException
- if an I/O error occurspublic static void copy(InputStream input, Writer output) throws IOException
InputStream
to chars on a
Writer
using the default character encoding of the platform.
This method buffers the input internally, so there is no need to use a
BufferedInputStream
.
This method uses InputStreamReader
.
input
- the InputStream
to read fromoutput
- the Writer
to write toNullPointerException
- if the input or output is nullIOException
- if an I/O error occurspublic static int copy(Reader input, Writer output) throws IOException
Reader
to a Writer
.
This method buffers the input internally, so there is no need to use a
BufferedReader
.
Large streams (over 2GB) will return a chars copied value of
-1
after the copy has completed since the correct
number of chars cannot be returned as an int. For large streams
use the copyLarge(Reader, Writer)
method.
input
- the Reader
to read fromoutput
- the Writer
to write toNullPointerException
- if the input or output is nullIOException
- if an I/O error occursArithmeticException
- if the character count is too largepublic static long copyLarge(Reader input, Writer output) throws IOException
Reader
to a Writer
.
This method buffers the input internally, so there is no need to use a
BufferedReader
.
input
- the Reader
to read fromoutput
- the Writer
to write toNullPointerException
- if the input or output is nullIOException
- if an I/O error occursCopyright © 2016. All rights reserved.