java.lang.Object
- org.springframework.util.StreamUtils

```
public abstract class StreamUtils
extends Object
```
Simple utility methods for dealing with streams. The copy methods of this class are similar to those defined in FileCopyUtils except that all affected streams are left open when done. All copy methods use a block size of 4096 bytes.
Mainly for use within the framework, but also useful for application code.
Since:
3.2.2
Author:
Juergen Hoeller, Phillip Webb, Brian Clozel
See Also:
FileCopyUtils

Field Summary
Fields
Modifier and Type Field Description
static int BUFFER_SIZE
The default buffer size used when copying bytes.

Constructor Summary
Constructors
Constructor Description
StreamUtils()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`copy(byte[] in, OutputStream out)`	Copy the contents of the given byte array to the given OutputStream.
`static int`	`copy(InputStream in, OutputStream out)`	Copy the contents of the given InputStream to the given OutputStream.
`static void`	`copy(String in, Charset charset, OutputStream out)`	Copy the contents of the given String to the given OutputStream.
`static long`	`copyRange(InputStream in, OutputStream out, long start, long end)`	Copy a range of content of the given InputStream to the given OutputStream.
`static byte[]`	`copyToByteArray(InputStream in)`	Copy the contents of the given InputStream into a new byte array.
`static String`	`copyToString(InputStream in, Charset charset)`	Copy the contents of the given InputStream into a String.
`static int`	`drain(InputStream in)`	Drain the remaining content of the given InputStream.
`static InputStream`	`emptyInput()`	Return an efficient empty `InputStream`.
`static InputStream`	`nonClosing(InputStream in)`	Return a variant of the given `InputStream` where calling `close()` has no effect.
`static OutputStream`	`nonClosing(OutputStream out)`	Return a variant of the given `OutputStream` where calling `close()` has no effect.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - BUFFER_SIZE
```
public static final int BUFFER_SIZE
```
    The default buffer size used when copying bytes.
    See Also:
    Constant Field Values
- Constructor Detail
  - StreamUtils
```
public StreamUtils()
```
- Method Detail
  - copyToByteArray
```
public static byte[] copyToByteArray(InputStream in)
                              throws IOException
```
    Copy the contents of the given InputStream into a new byte array.
    Leaves the stream open when done.
    Parameters:
    in - the stream to copy from (may be null or empty)
    Returns:
    the new byte array that has been copied to (possibly empty)
    Throws:
    IOException - in case of I/O errors
  - copyToString
```
public static String copyToString(InputStream in,
                                  Charset charset)
                           throws IOException
```
    Copy the contents of the given InputStream into a String.
    Leaves the stream open when done.
    Parameters:
    in - the InputStream to copy from (may be null or empty)
    charset - the Charset to use to decode the bytes
    Returns:
    the String that has been copied to (possibly empty)
    Throws:
    IOException - in case of I/O errors
  - copy
```
public static void copy(byte[] in,
                        OutputStream out)
                 throws IOException
```
    Copy the contents of the given byte array to the given OutputStream.
    Leaves the stream open when done.
    Parameters:
    in - the byte array to copy from
    out - the OutputStream to copy to
    Throws:
    IOException - in case of I/O errors
  - copy
```
public static void copy(String in,
                        Charset charset,
                        OutputStream out)
                 throws IOException
```
    Copy the contents of the given String to the given OutputStream.
    Leaves the stream open when done.
    Parameters:
    in - the String to copy from
    charset - the Charset
    out - the OutputStream to copy to
    Throws:
    IOException - in case of I/O errors
  - copy
```
public static int copy(InputStream in,
                       OutputStream out)
                throws IOException
```
    Copy the contents of the given InputStream to the given OutputStream.
    Leaves both streams open when done.
    Parameters:
    in - the InputStream to copy from
    out - the OutputStream to copy to
    Returns:
    the number of bytes copied
    Throws:
    IOException - in case of I/O errors
  - copyRange
```
public static long copyRange(InputStream in,
                             OutputStream out,
                             long start,
                             long end)
                      throws IOException
```
    Copy a range of content of the given InputStream to the given OutputStream.
    If the specified range exceeds the length of the InputStream, this copies up to the end of the stream and returns the actual number of copied bytes.
    Leaves both streams open when done.
    Parameters:
    in - the InputStream to copy from
    out - the OutputStream to copy to
    start - the position to start copying from
    end - the position to end copying
    Returns:
    the number of bytes copied
    Throws:
    IOException - in case of I/O errors
    Since:
    4.3
  - drain
```
public static int drain(InputStream in)
                 throws IOException
```
    Drain the remaining content of the given InputStream.
    Leaves the InputStream open when done.
    Parameters:
    in - the InputStream to drain
    Returns:
    the number of bytes read
    Throws:
    IOException - in case of I/O errors
    Since:
    4.3
  - emptyInput
```
public static InputStream emptyInput()
```
    Return an efficient empty InputStream.
    Returns:
    a ByteArrayInputStream based on an empty byte array
    Since:
    4.2.2
  - nonClosing
```
public static InputStream nonClosing(InputStream in)
```
    Return a variant of the given InputStream where calling close() has no effect.
    Parameters:
    in - the InputStream to decorate
    Returns:
    a version of the InputStream that ignores calls to close
  - nonClosing
```
public static OutputStream nonClosing(OutputStream out)
```
    Return a variant of the given OutputStream where calling close() has no effect.
    Parameters:
    out - the OutputStream to decorate
    Returns:
    a version of the OutputStream that ignores calls to close

Class StreamUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

BUFFER_SIZE

Constructor Detail

StreamUtils

Method Detail

copyToByteArray

copyToString

copy

copy

copy

copyRange

drain

emptyInput

nonClosing

nonClosing