Class IOUtils
- java.lang.Object
-
- org.zeroturnaround.zip.commons.IOUtils
-
public class IOUtils extends java.lang.Object
This is a class that has been made significantly smaller (deleted a bunch of methods) and originally is from the Apache Commons IO 2.2 package (the latest version that supports Java 1.5). All license and other documentation is intact. General IO stream manipulation utilities.This class provides static utility methods for input/output operations.
- closeQuietly - these methods close a stream ignoring nulls and exceptions
- toXxx/read - these methods read data from a stream
- write - these methods write data to a stream
- copy - these methods copy all the data from one stream to another
- contentEquals - these methods compare the content of two streams
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
orBufferedReader
. 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.
- Version:
- $Id: IOUtils.java 1304177 2012-03-23 03:36:44Z ggregory $
-
-
Field Summary
Fields Modifier and Type Field Description private static int
DEFAULT_BUFFER_SIZE
The default buffer size (4096) to use forcopyLarge(InputStream, OutputStream)
andcopyLarge(Reader, Writer)
static char
DIR_SEPARATOR
The system directory separator character.static char
DIR_SEPARATOR_UNIX
The Unix directory separator character.static char
DIR_SEPARATOR_WINDOWS
The Windows directory separator character.private static int
EOF
static java.lang.String
LINE_SEPARATOR
The system line separator string.static java.lang.String
LINE_SEPARATOR_UNIX
The Unix line separator string.static java.lang.String
LINE_SEPARATOR_WINDOWS
The Windows line separator string.
-
Constructor Summary
Constructors Constructor Description IOUtils()
Instances should NOT be constructed in standard programming.
-
Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static void
closeQuietly(java.io.Closeable closeable)
Unconditionally close aCloseable
.static void
closeQuietly(java.io.InputStream input)
Unconditionally close anInputStream
.static void
closeQuietly(java.io.OutputStream output)
Unconditionally close anOutputStream
.static boolean
contentEquals(java.io.InputStream input1, java.io.InputStream input2)
Compare the contents of two Streams to determine if they are equal or not.static int
copy(java.io.InputStream input, java.io.OutputStream output)
Copy bytes from anInputStream
to anOutputStream
.static void
copy(java.io.InputStream input, java.io.Writer output)
Copy bytes from anInputStream
to chars on aWriter
using the default character encoding of the platform.static void
copy(java.io.InputStream input, java.io.Writer output, java.lang.String encoding)
Copy bytes from anInputStream
to chars on aWriter
using the specified character encoding.static int
copy(java.io.Reader input, java.io.Writer output)
Copy chars from aReader
to aWriter
.static long
copyLarge(java.io.InputStream input, java.io.OutputStream output)
Copy bytes from a large (over 2GB)InputStream
to anOutputStream
.static long
copyLarge(java.io.InputStream input, java.io.OutputStream output, byte[] buffer)
Copy bytes from a large (over 2GB)InputStream
to anOutputStream
.static long
copyLarge(java.io.Reader input, java.io.Writer output)
Copy chars from a large (over 2GB)Reader
to aWriter
.static long
copyLarge(java.io.Reader input, java.io.Writer output, char[] buffer)
Copy chars from a large (over 2GB)Reader
to aWriter
.static byte[]
toByteArray(java.io.InputStream input)
Get the contents of anInputStream
as abyte[]
.static java.lang.String
toString(java.io.InputStream input, java.lang.String encoding)
Get the contents of anInputStream
as a String using the specified character encoding.
-
-
-
Field Detail
-
EOF
private static final int EOF
- See Also:
- Constant Field Values
-
DIR_SEPARATOR_UNIX
public static final char DIR_SEPARATOR_UNIX
The Unix directory separator character.- See Also:
- Constant Field Values
-
DIR_SEPARATOR_WINDOWS
public static final char DIR_SEPARATOR_WINDOWS
The Windows directory separator character.- See Also:
- Constant Field Values
-
DIR_SEPARATOR
public static final char DIR_SEPARATOR
The system directory separator character.
-
LINE_SEPARATOR_UNIX
public static final java.lang.String LINE_SEPARATOR_UNIX
The Unix line separator string.- See Also:
- Constant Field Values
-
LINE_SEPARATOR_WINDOWS
public static final java.lang.String LINE_SEPARATOR_WINDOWS
The Windows line separator string.- See Also:
- Constant Field Values
-
LINE_SEPARATOR
public static final java.lang.String LINE_SEPARATOR
The system line separator string.
-
DEFAULT_BUFFER_SIZE
private static final int DEFAULT_BUFFER_SIZE
The default buffer size (4096) to use forcopyLarge(InputStream, OutputStream)
andcopyLarge(Reader, Writer)
- See Also:
- Constant Field Values
-
-
Method Detail
-
closeQuietly
public static void closeQuietly(java.io.InputStream input)
Unconditionally close anInputStream
.Equivalent to
InputStream.close()
, except any exceptions will be ignored. This is typically used in finally blocks.Example code:
byte[] data = new byte[1024]; InputStream in = null; try { in = new FileInputStream("foo.txt"); in.read(data); in.close(); //close errors are handled } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(in); }
- Parameters:
input
- the InputStream to close, may be null or already closed
-
closeQuietly
public static void closeQuietly(java.io.OutputStream output)
Unconditionally close anOutputStream
.Equivalent to
OutputStream.close()
, except any exceptions will be ignored. This is typically used in finally blocks.Example code:
byte[] data = "Hello, World".getBytes(); OutputStream out = null; try { out = new FileOutputStream("foo.txt"); out.write(data); out.close(); //close errors are handled } catch (IOException e) { // error handling } finally { IOUtils.closeQuietly(out); }
- Parameters:
output
- the OutputStream to close, may be null or already closed
-
closeQuietly
public static void closeQuietly(java.io.Closeable closeable)
Unconditionally close aCloseable
.Equivalent to
Closeable.close()
, except any exceptions will be ignored. This is typically used in finally blocks.Example code:
Closeable closeable = null; try { closeable = new FileReader("foo.txt"); // process closeable closeable.close(); } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(closeable); }
- Parameters:
closeable
- the object to close, may be null or already closed- Since:
- 2.0
-
toByteArray
public static byte[] toByteArray(java.io.InputStream input) throws java.io.IOException
Get the contents of anInputStream
as abyte[]
.This method buffers the input internally, so there is no need to use a
BufferedInputStream
.- Parameters:
input
- theInputStream
to read from- Returns:
- the requested byte array
- Throws:
java.lang.NullPointerException
- if the input is nulljava.io.IOException
- if an I/O error occurs
-
toString
public static java.lang.String toString(java.io.InputStream input, java.lang.String encoding) throws java.io.IOException
Get the contents of anInputStream
as a String using the specified character encoding.Character encoding names can be found at IANA.
This method buffers the input internally, so there is no need to use a
BufferedInputStream
.- Parameters:
input
- theInputStream
to read fromencoding
- the encoding to use, null means platform default- Returns:
- the requested String
- Throws:
java.lang.NullPointerException
- if the input is nulljava.io.IOException
- if an I/O error occurs
-
copy
public static int copy(java.io.InputStream input, java.io.OutputStream output) throws java.io.IOException
Copy bytes from anInputStream
to anOutputStream
.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 thecopyLarge(InputStream, OutputStream)
method.- Parameters:
input
- theInputStream
to read fromoutput
- theOutputStream
to write to- Returns:
- the number of bytes copied, or -1 if > Integer.MAX_VALUE
- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 1.1
-
copyLarge
public static long copyLarge(java.io.InputStream input, java.io.OutputStream output) throws java.io.IOException
Copy bytes from a large (over 2GB)InputStream
to anOutputStream
.This method buffers the input internally, so there is no need to use a
BufferedInputStream
.The buffer size is given by
DEFAULT_BUFFER_SIZE
.- Parameters:
input
- theInputStream
to read fromoutput
- theOutputStream
to write to- Returns:
- the number of bytes copied
- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 1.3
-
copyLarge
public static long copyLarge(java.io.InputStream input, java.io.OutputStream output, byte[] buffer) throws java.io.IOException
Copy bytes from a large (over 2GB)InputStream
to anOutputStream
.This method uses the provided buffer, so there is no need to use a
BufferedInputStream
.- Parameters:
input
- theInputStream
to read fromoutput
- theOutputStream
to write tobuffer
- the buffer to use for the copy- Returns:
- the number of bytes copied
- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 2.2
-
copy
public static void copy(java.io.InputStream input, java.io.Writer output) throws java.io.IOException
Copy bytes from anInputStream
to chars on aWriter
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
.- Parameters:
input
- theInputStream
to read fromoutput
- theWriter
to write to- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 1.1
-
copy
public static void copy(java.io.InputStream input, java.io.Writer output, java.lang.String encoding) throws java.io.IOException
Copy bytes from anInputStream
to chars on aWriter
using the specified character encoding.This method buffers the input internally, so there is no need to use a
BufferedInputStream
.Character encoding names can be found at IANA.
This method uses
InputStreamReader
.- Parameters:
input
- theInputStream
to read fromoutput
- theWriter
to write toencoding
- the encoding to use, null means platform default- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 1.1
-
copy
public static int copy(java.io.Reader input, java.io.Writer output) throws java.io.IOException
Copy chars from aReader
to aWriter
.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 thecopyLarge(Reader, Writer)
method.- Parameters:
input
- theReader
to read fromoutput
- theWriter
to write to- Returns:
- the number of characters copied, or -1 if > Integer.MAX_VALUE
- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 1.1
-
copyLarge
public static long copyLarge(java.io.Reader input, java.io.Writer output) throws java.io.IOException
Copy chars from a large (over 2GB)Reader
to aWriter
.This method buffers the input internally, so there is no need to use a
BufferedReader
.The buffer size is given by
DEFAULT_BUFFER_SIZE
.- Parameters:
input
- theReader
to read fromoutput
- theWriter
to write to- Returns:
- the number of characters copied
- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 1.3
-
copyLarge
public static long copyLarge(java.io.Reader input, java.io.Writer output, char[] buffer) throws java.io.IOException
Copy chars from a large (over 2GB)Reader
to aWriter
.This method uses the provided buffer, so there is no need to use a
BufferedReader
.- Parameters:
input
- theReader
to read fromoutput
- theWriter
to write tobuffer
- the buffer to be used for the copy- Returns:
- the number of characters copied
- Throws:
java.lang.NullPointerException
- if the input or output is nulljava.io.IOException
- if an I/O error occurs- Since:
- 2.2
-
contentEquals
public static boolean contentEquals(java.io.InputStream input1, java.io.InputStream input2) throws java.io.IOException
Compare the contents of two Streams to determine if they are equal or not.This method buffers the input internally using
BufferedInputStream
if they are not already buffered.- Parameters:
input1
- the first streaminput2
- the second stream- Returns:
- true if the content of the streams are equal or they both don't exist, false otherwise
- Throws:
java.lang.NullPointerException
- if either input is nulljava.io.IOException
- if an I/O error occurs
-
-