PDFStream (Apache FOP Core 2.11 API)
Date: 2025-04-24

org.apache.fop.pdf

## Class PDFStream

- java.lang.Object
- - org.apache.fop.pdf.PDFObject
  - - org.apache.fop.pdf.AbstractPDFStream
    - - org.apache.fop.pdf.PDFStream

- All Implemented Interfaces:
    PDFWritable
  Direct Known Subclasses:
    ObjectStream, PDFCMap, PDFEmbeddedFile, PDFICCStream, PDFMetadata

      public class PDFStream
      extends AbstractPDFStream

  Class representing a PDF stream.

  A derivative of the PDF Object, a PDF Stream has not only a dictionary but a stream of PDF commands. The stream of commands is where the real work is done, the dictionary just provides information like the stream length.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected StreamCache` | `data` The stream of PDF commands

    - ### Fields inherited from class org.apache.fop.pdf.PDFObject

      `log`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `PDFStream()` Create an empty stream object
    `PDFStream(boolean encodeOnTheFly)`
    `PDFStream(PDFDictionary dictionary)`
    `PDFStream(PDFDictionary dictionary, boolean encodeOnTheFly)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `add(String s)` Append data to the stream
    `void` | `add(StringBuffer sb)` Append data to the stream
    `OutputStream` | `getBufferOutputStream()` Returns an OutputStream that can be used to write to the buffer which is used to build up the PDF stream.
    `Writer` | `getBufferWriter()` Returns a Writer that writes to the OutputStream of the buffer.
    `int` | `getDataLength()` Returns the size of the content.
    `protected int` | `getSizeHint()` Returns a value that hints at the size of the encoded stream.
    `int` | `output(OutputStream stream)` Overload the base object method so we don't have to copy byte arrays around so much Write the PDF represention of this object
    `protected void` | `outputRawStreamData(OutputStream out)` Sends the raw stream data to the target OutputStream.
    `void` | `setData(byte[] data)` Used to set the contents of the PDF stream.
    `String` | `streamHashCode()`

    - ### Methods inherited from class org.apache.fop.pdf.AbstractPDFStream

      `encodeAndWriteStream, encodeStream, get, getChildren, getDefaultFilterName, getDictionary, getFilterList, multipleFiltersAllowed, outputStreamData, populateStreamDict, prepareImplicitFilters, put, registerChildren, setDocument, setupFilterList, supportsObjectStream`

    - ### Methods inherited from class org.apache.fop.pdf.PDFObject

      `contentEquals, encode, encodeBinaryToHexString, encodeString, encodeText, formatObject, getDocument, getDocumentSafely, getGeneration, getObjectID, getObjectNumber, getParent, hasObjectNumber, makeReference, outputInline, referencePDF, setObjectNumber, setObjectNumber, setObjectNumber, setParent, toPDF, toPDFString`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### data

          protected StreamCache data

      The stream of PDF commands

  - ### Constructor Detail

    - #### PDFStream

          public PDFStream()

      Create an empty stream object

    - #### PDFStream

          public PDFStream(PDFDictionary dictionary)

    - #### PDFStream

          public PDFStream(PDFDictionary dictionary,
                           boolean encodeOnTheFly)

    - #### PDFStream

          public PDFStream(boolean encodeOnTheFly)

  - ### Method Detail

    - #### add

          public void add(String s)

      Append data to the stream
      Parameters:
        `s` - the string of PDF to add

    - #### add

          public void add(StringBuffer sb)

      Append data to the stream
      Parameters:
        `sb` - the string buffer of PDF to add

    - #### getBufferWriter

          public Writer getBufferWriter()

      Returns a Writer that writes to the OutputStream of the buffer.
      Returns:
        the Writer

    - #### getBufferOutputStream

          public OutputStream getBufferOutputStream()
                                             throws IOException

      Returns an OutputStream that can be used to write to the buffer which is used to build up the PDF stream.
      Returns:
        the OutputStream
      Throws:
        `IOException` - In case of an I/O problem

    - #### setData

          public void setData(byte[] data)
                       throws IOException

      Used to set the contents of the PDF stream.
      Parameters:
        `data` - the contents as a byte array
      Throws:
        `IOException` - in case of an I/O problem

    - #### getDataLength

          public int getDataLength()

      Returns the size of the content.
      Returns:
        size of the content

    - #### getSizeHint

          protected int getSizeHint()
                             throws IOException

      Returns a value that hints at the size of the encoded stream. This is used to optimize buffer allocation so fewer buffer reallocations are necessary.
      Specified by:
        `getSizeHint` in class `AbstractPDFStream`
      Returns:
        an estimated size (0 if no hint can be given)
      Throws:
        `IOException` - in case of an I/O problem

    - #### outputRawStreamData

          protected void outputRawStreamData(OutputStream out)
                                      throws IOException

      Sends the raw stream data to the target OutputStream.
      Specified by:
        `outputRawStreamData` in class `AbstractPDFStream`
      Parameters:
        `out` - OutputStream to write to
      Throws:
        `IOException` - In case of an I/O problem

    - #### output

          public int output(OutputStream stream)
                     throws IOException

      Overload the base object method so we don't have to copy byte arrays around so much Write the PDF represention of this object
      Overrides:
        `output` in class `AbstractPDFStream`
      Parameters:
        `stream` - the stream to write the PDF to
      Returns:
        the number of bytes written
      Throws:
        `IOException` - if there is an error writing to the stream

    - #### streamHashCode

          public String streamHashCode()
                                throws IOException

      Throws:
        `IOException`

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