Package org.springframework.core.io

Class InputStreamResource

java.lang.Object

org.springframework.core.io.AbstractResource

org.springframework.core.io.InputStreamResource

All Implemented Interfaces:

InputStreamSource, Resource

public class InputStreamResource
extends AbstractResource

Resource implementation for a given InputStream or a given InputStreamSource (which can be supplied as a lambda expression) for a lazy InputStream on demand.

Should only be used if no other specific Resource implementation is applicable. In particular, prefer ByteArrayResource or any of the file-based Resource implementations if possible. If you need to obtain a custom stream multiple times, use a custom AbstractResource subclass with a corresponding getInputStream() implementation.

In contrast to other Resource implementations, this is a descriptor for an already opened resource - therefore returning true from isOpen(). Do not use an InputStreamResource if you need to keep the resource descriptor somewhere, or if you need to read from a stream multiple times. This also applies when constructed with an InputStreamSource which lazily obtains the stream but only allows for single access as well.

NOTE: This class does not provide an independent AbstractResource.contentLength() implementation: Any such call will consume the given InputStream! Consider overriding #contentLength() with a custom implementation if possible. For any other purpose, it is not recommended to extend from this class; this is particularly true when used with Spring's web resource rendering which specifically skips #contentLength() for this exact class only.

Since:

28.12.2003

Author:

Juergen Hoeller, Sam Brannen

See Also:

• ByteArrayResource
• ClassPathResource
• FileSystemResource
• UrlResource

Constructor Summary

Constructors

Constructor	Description
InputStreamResource(InputStream inputStream)	Create a new InputStreamResource for an existing InputStream.
InputStreamResource(InputStream inputStream, String description)	Create a new InputStreamResource for an existing InputStream.
InputStreamResource(InputStreamSource inputStreamSource)	Create a new InputStreamResource with a lazy InputStream for single use.
InputStreamResource(InputStreamSource inputStreamSource, String description)	Create a new InputStreamResource with a lazy InputStream for single use.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)	This implementation compares the underlying InputStream.
boolean	exists()	This implementation always returns true.
String	getDescription()	This implementation returns a description that includes the passed-in description, if any.
InputStream	getInputStream()	This implementation throws IllegalStateException if attempting to read the underlying stream multiple times.
int	hashCode()	This implementation returns the hash code of the underlying InputStream.
boolean	isOpen()	This implementation always returns true.

Methods inherited from class org.springframework.core.io.AbstractResource

contentLength, createRelative, getFile, getFileForLastModifiedCheck, getFilename, getURI, getURL, isFile, isReadable, lastModified, readableChannel, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.springframework.core.io.Resource

getContentAsByteArray, getContentAsString

Constructor Details

InputStreamResource

public InputStreamResource(InputStreamSource inputStreamSource)

Create a new InputStreamResource with a lazy InputStream for single use.

Parameters:

inputStreamSource - an on-demand source for a single-use InputStream

Since:

6.1.7

InputStreamResource

public InputStreamResource(InputStreamSource inputStreamSource,
 @Nullable
 String description)

Create a new InputStreamResource with a lazy InputStream for single use.

Parameters:

inputStreamSource - an on-demand source for a single-use InputStream

description - where the InputStream comes from

Since:

6.1.7

InputStreamResource

public InputStreamResource(InputStream inputStream)

Create a new InputStreamResource for an existing InputStream.

Consider retrieving the InputStream on demand if possible, reducing its lifetime and reliably opening it and closing it through regular InputStreamSource.getInputStream() usage.

Parameters:

inputStream - the InputStream to use

See Also:

• InputStreamResource(InputStreamSource)

InputStreamResource

public InputStreamResource(InputStream inputStream,
 @Nullable
 String description)

Create a new InputStreamResource for an existing InputStream.

Parameters:

inputStream - the InputStream to use

description - where the InputStream comes from

See Also:

• InputStreamResource(InputStreamSource, String)

Method Details

exists

public boolean exists()

This implementation always returns true.

Specified by:

exists in interface Resource

Overrides:

exists in class AbstractResource

isOpen

public boolean isOpen()

This implementation always returns true.

Specified by:

isOpen in interface Resource

Overrides:

isOpen in class AbstractResource

getInputStream

public InputStream getInputStream()
                           throws IOException,
IllegalStateException

This implementation throws IllegalStateException if attempting to read the underlying stream multiple times.

Returns:

the input stream for the underlying resource (must not be null)

Throws:

FileNotFoundException - if the underlying resource does not exist

IOException - if the content stream could not be opened

IllegalStateException

See Also:

• Resource.isReadable()
• Resource.isOpen()

getDescription

public String getDescription()

This implementation returns a description that includes the passed-in description, if any.

See Also:

• Object.toString()

equals

public boolean equals(@Nullable
 Object other)

This implementation compares the underlying InputStream.

Overrides:

equals in class AbstractResource

See Also:

• Resource.getDescription()

hashCode

public int hashCode()

This implementation returns the hash code of the underlying InputStream.

Overrides:

hashCode in class AbstractResource

See Also:

• Resource.getDescription()