FileBackedOutputStream (Guava: Google Core Libraries for Java 19.0-rc3 API)

java.lang.Object
- java.io.OutputStream
- - com.google.common.io.FileBackedOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable
```
@Beta
public final class FileBackedOutputStream
extends OutputStream
```
An OutputStream that starts buffering to a byte array, but switches to file buffering once the data reaches a configurable size.
This class is thread-safe.

Since:

1.0

Author:

Chris Nokleberg

Constructor Summary

Constructors
Constructor and Description
`FileBackedOutputStream(int fileThreshold)` Creates a new instance that uses the given file threshold, and does not reset the data when the `ByteSource` returned by `asByteSource()` is finalized.
`FileBackedOutputStream(int fileThreshold, boolean resetOnFinalize)` Creates a new instance that uses the given file threshold, and optionally resets the data when the `ByteSource` returned by `asByteSource()` is finalized.

Method Summary

Methods
Modifier and Type	Method and Description
`ByteSource`	`asByteSource()` Returns a readable `ByteSource` view of the data that has been written to this stream.
`void`	`close()`
`void`	`flush()`
`void`	`reset()` Calls `close()` if not already closed, and then resets this object back to its initial state, for reuse.
`void`	`write(byte[] b)`
`void`	`write(byte[] b, int off, int len)`
`void`	`write(int b)`

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

- Constructor Detail
  - FileBackedOutputStream
```
public FileBackedOutputStream(int fileThreshold)
```
    Creates a new instance that uses the given file threshold, and does not reset the data when the ByteSource returned by asByteSource() is finalized.
    
    Parameters:
    fileThreshold - the number of bytes before the stream should switch to buffering to a file
  - FileBackedOutputStream
```
public FileBackedOutputStream(int fileThreshold,
                      boolean resetOnFinalize)
```
    Creates a new instance that uses the given file threshold, and optionally resets the data when the ByteSource returned by asByteSource() is finalized.
    
    Parameters:
    fileThreshold - the number of bytes before the stream should switch to buffering to a file
    resetOnFinalize - if true, the reset() method will be called when the ByteSource returned by asByteSource() is finalized
- Method Detail
  - asByteSource
```
public ByteSource asByteSource()
```
    Returns a readable ByteSource view of the data that has been written to this stream.
    
    Since:
    
    15.0
  - reset
```
public void reset()
           throws IOException
```
    Calls close() if not already closed, and then resets this object back to its initial state, for reuse. If data was buffered to a file, it will be deleted.
    
    Throws:
    
    IOException - if an I/O error occurred while deleting the file buffer
  - write
```
public void write(int b)
           throws IOException
```
    Specified by:
    
    write in class OutputStream
    
    Throws:
    
    IOException
  - write
```
public void write(byte[] b)
           throws IOException
```
    Overrides:
    
    write in class OutputStream
    
    Throws:
    
    IOException
  - write
```
public void write(byte[] b,
         int off,
         int len)
           throws IOException
```
    Overrides:
    
    write in class OutputStream
    
    Throws:
    
    IOException
  - close
```
public void close()
           throws IOException
```
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class OutputStream
    
    Throws:
    
    IOException
  - flush
```
public void flush()
           throws IOException
```
    Specified by:
    
    flush in interface Flushable
    
    Overrides:
    
    flush in class OutputStream
    
    Throws:
    
    IOException

Class FileBackedOutputStream

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FileBackedOutputStream

FileBackedOutputStream

Method Detail

asByteSource

reset

write

write

write

close

flush