java.lang.Object
- de.aristaflow.adept2.util.io.RereadableContent

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

FileContent, MemoryContent, WrappingContent
```
public abstract class RereadableContent
extends Object
implements Closeable
```
The RereadableContent can be used when the content of an InputStream needs to be processed multiple times. Depending on its eventual size the whole content of the input stream is buffered in-memory - up to a certain threshold - or in a temporary file.
The RereadableContent as well as the provided input streams must be closed after use! This can be ensured by adhering to the following template:
```
 try (RereadableContentBuilder rcb = new RereadableContentBuilder();
      RereadableContent rc = rcb.data(inputStream).build())
 {
   ...
   try (InputStream is = rc.getInputStream())
   {
     ...
   }
   ...
   try (InputStream is = rc.getInputStream())
   {
     ...
   }
   ...
 }
 
```
If you want to fill the builder using an OutputStream make sure to fill and close this before building:
```
 try (RereadableContentBuilder rcb = new RereadableContentBuilder())
 {
   ...
   try (OutputStream os = rcb.getOutputStream())
   {
     ...
   }
   ...
   try (RereadableContent rc = rcb.build())
   {
     ...
   }
 }
 
```
You can also let the RereadableContent or the InputStreams get out of the block structure. But make sure to Closeable.close() them all.
```
 
 RereadableContent rc;
 try (RereadableContentBuilder rcb = new RereadableContentBuilder())
 {
   ...
   try (OutputStream os = rcb.getOutputStream())
   {
     ...
   }
   rc = rbc.build();
 }
 ...
 InputStream is1 = rc.getInputStream())
 ...
 InputStream is2 = input.getInputStream())
 ...
 // Just make sure to close them all (in arbitrary order).
 is1.close();
 ...
 rc.close();
 ...
 is2.close();
 ...
 
 
```
All InputStream instances created by this class will be AttributedInputStream also providing the size and the SHA-512 hash of the stream data. The created streams will be tracked. The RereadableContent will not be closed when at least one of its input streams is still in use (has not been closed). It is ensured that closing will be done by the last active input stream (or by the RereadableContent). Also all of these will close in a cleanup to make sure that they will be really closed.
This class is thread-safe.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`protected static class`	`RereadableContent.RrcCleanup`	The `CleanupTask` doing the clean-up (`close()`) independently from the `RereadableContent`.
`protected static class`	`RereadableContent.RrcInputStream`	This class is an input stream that also provides the `RereadableContent` it has been created for.

Field Summary

Fields
Modifier and Type	Field	Description
`protected Cleanup<IOException>`	`cleanup`	The clean-up called as post-mortem action of this `RereadableContent`.
`protected Collection<Object>`	`existingStreams`	All streams that have been created by this `RereadableContent` including itself are identified by an arbitrary `Object`.
`protected Closeable`	`finalCleanup`	The final clean-up to be executed after all streams and this `RereadableContent` have been closed/cleaned up.
`protected static String`	`RRC_INPUT_STREAM_SIZE`	The name of the `Long` attribute providing the size of the input stream in bytes.
`protected byte[]`	`sha512hash`	The SHA-512 hash of the content.
`protected long`	`size`	The size of the content.

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`RereadableContent(long size, byte[] sha512hash, Closeable finalCleanup)`	Creates a new `RereadableContent` for the designated data.
`protected`	`RereadableContent(RereadableContent wrapped)`	Creates a new `RereadableContent` wrapping the designated `RereadableContent` and creating a new input stream to keep the wrapped `RereadableContent` alive.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes the underlying stream or deletes the underlying file if there is no unclosed `getInputStream()`.
`protected abstract InputStream`	`createInputStream()`	Creates a new input stream for the content.
`boolean`	`equals(Object obj)`
`AttributedInputStream`	`getInputStream()`	Gets an input stream for the data.
`byte[]`	`getSHA512Hash()`	Gets the SHA—512 hash of the content.
`long`	`getSize()`	Gets the size of the content.
`static Long`	`getSize(InputStream is)`	Gets the size of the designated input stream in case it is provided via `RRC_INPUT_STREAM_SIZE`, `null` otherwise.
`int`	`hashCode()`

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

- Field Detail
  - RRC_INPUT_STREAM_SIZE
```
protected static final String RRC_INPUT_STREAM_SIZE
```
    The name of the Long attribute providing the size of the input stream in bytes.
    
    See Also:
    
    Attributable, Constant Field Values
  - size
```
protected final long size
```
    The size of the content.
  - sha512hash
```
protected final byte[] sha512hash
```
    The SHA-512 hash of the content.
  - existingStreams
```
protected final Collection<Object> existingStreams
```
    All streams that have been created by this RereadableContent including itself are identified by an arbitrary Object. They have a clean-up task used for InputStream.close() as well as post-mortem action. The task removes the Object and the last one in the collection performs cleaning up the RereadableContent, for instance deleting the temporary file.
  - finalCleanup
```
protected final Closeable finalCleanup
```
    The final clean-up to be executed after all streams and this RereadableContent have been closed/cleaned up.
  - cleanup
```
protected final Cleanup<IOException> cleanup
```
    The clean-up called as post-mortem action of this RereadableContent. Since this is the same logic, it is also used by close().
- Constructor Detail
  - RereadableContent
```
protected RereadableContent(long size,
                            byte[] sha512hash,
                            Closeable finalCleanup)
```
    Creates a new RereadableContent for the designated data.
    
    Parameters:
    
    size - The size of the content.
    
    sha512hash - The SHA-512 hash of the content.
    
    finalCleanup - The final clean-up to be executed after all streams and the RereadableContent have been closed/cleaned up.
  - RereadableContent
```
protected RereadableContent(RereadableContent wrapped)
                     throws IOException
```
    Creates a new RereadableContent wrapping the designated RereadableContent and creating a new input stream to keep the wrapped RereadableContent alive.
    
    Parameters:
    
    wrapped - The wrapped RereadableContent.
    
    Throws:
    
    IOException - If creating a new input stream from the designated RereadableContent fails, an IOException will be thrown.
- Method Detail
  - getSize
```
public long getSize()
```
    Gets the size of the content.
    
    Returns:
    
    The size of the content.
  - getSHA512Hash
```
public byte[] getSHA512Hash()
```
    Gets the SHA—512 hash of the content.
    
    Returns:
    
    The SHA-512 hash of the content.
  - getInputStream
```
public AttributedInputStream getInputStream()
                                     throws IOException
```
    Gets an input stream for the data. This method may be called multiple times. The returned stream must be closed properly after use!
    Closing will not affect the InputStream.
    
    Returns:
    
    An input stream for the data. The caller is responsible for closing.
    
    Throws:
    
    IOException - If there are problems creating a new input stream for the data or this RereadableContent has already been closed, an IOException will be thrown.
  - createInputStream
```
protected abstract InputStream createInputStream()
                                          throws IOException
```
    Creates a new input stream for the content.
    
    Returns:
    
    A new input stream for the content. The caller is responsible for closing.
    
    Throws:
    
    IOException - If there are problems creating a new input stream for the content, an IOException will be thrown.
  - close
```
public final void close()
                 throws IOException
```
    Closes the underlying stream or deletes the underlying file if there is no unclosed getInputStream(). If there are input streams of this RereadableContent that have not been closed yet, closing deferred until closing the last one of these input streams.
    
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface Closeable
    
    Throws:
    
    IOException - If closing or deleting fails, an IOException will be thrown.
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - getSize
```
public static Long getSize(InputStream is)
```
    Gets the size of the designated input stream in case it is provided via RRC_INPUT_STREAM_SIZE, null otherwise.
    
    Parameters:
    
    is - The input stream for which to get the size (from the corresponding attribute).
    
    Returns:
    
    The value of the size attribute of the designated input stream or null if not available.

Class RereadableContent

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

RRC_INPUT_STREAM_SIZE

size

sha512hash

existingStreams

finalCleanup

cleanup

Constructor Detail

RereadableContent

RereadableContent

Method Detail

getSize

getSHA512Hash

getInputStream

createInputStream

close

equals

hashCode

getSize