MemoryMappedFileInputStream (The Adobe AEM Quickstart and Web Application. 6.6.0)

java.lang.Object
- java.io.InputStream
- - org.apache.commons.io.input.MemoryMappedFileInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable
```
public final class MemoryMappedFileInputStream
extends java.io.InputStream
```
An InputStream that utilizes memory mapped files to improve performance. A sliding window of the file is mapped to memory to avoid mapping the entire file to memory at one time. The size of the sliding buffer is configurable.
For most operating systems, mapping a file into memory is more expensive than reading or writing a few tens of kilobytes of data. From the standpoint of performance. it is generally only worth mapping relatively large files into memory.

Note: Use of this class does not necessarily obviate the need to use a BufferedInputStream. Depending on the use case, the use of buffering may still further improve performance. For example:

To build an instance, use MemoryMappedFileInputStream.Builder.
```
 BufferedInputStream s = new BufferedInputStream(new GzipInputStream(
   MemoryMappedFileInputStream.builder()
     .setPath(path)
     .setBufferSize(256 * 1024)
     .get()));
 
```
should outperform:
```
 new GzipInputStream(new MemoryMappedFileInputStream(path))
 
```
```
 GzipInputStream s = new GzipInputStream(
   MemoryMappedFileInputStream.builder()
     .setPath(path)
     .setBufferSize(256 * 1024)
     .get());
 
```
Since:

2.12.0

See Also:

MemoryMappedFileInputStream.Builder

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class MemoryMappedFileInputStream.Builder
Builds a new MemoryMappedFileInputStream.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`available()`
`static MemoryMappedFileInputStream.Builder`	`builder()`	Constructs a new `MemoryMappedFileInputStream.Builder`.
`void`	`close()`
`int`	`read()`
`int`	`read(byte[] b, int off, int len)`
`long`	`skip(long n)`

Methods inherited from class java.io.InputStream
mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, transferTo

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

- Method Detail
  - builder
```
public static MemoryMappedFileInputStream.Builder builder()
```
    Constructs a new MemoryMappedFileInputStream.Builder.
    
    Returns:
    
    a new MemoryMappedFileInputStream.Builder.
    
    Since:
    
    2.12.0
  - available
```
public int available()
              throws java.io.IOException
```
    Overrides:
    
    available in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
  - close
```
public void close()
           throws java.io.IOException
```
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Overrides:
    
    close in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
  - read
```
public int read()
         throws java.io.IOException
```
    Specified by:
    
    read in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
  - read
```
public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException
```
    Overrides:
    
    read in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
  - skip
```
public long skip(long n)
          throws java.io.IOException
```
    Overrides:
    
    skip in class java.io.InputStream
    
    Throws:
    
    java.io.IOException