Package org.docx4j.org.apache.poi.poifs.storage

Class DataInputBlock

java.lang.Object
org.docx4j.org.apache.poi.poifs.storage.DataInputBlock
public final class DataInputBlock
extends java.lang.Object
Wraps a byte array and provides simple data input access. Internally, this class maintains a buffer read index, so that for the most part, primitive data can be read in a data-input-stream-like manner.

Note - the calling class should call the available() method to detect end-of-buffer and move to the next data block when the current is exhausted. For optimisation reasons, no error handling is performed in this class. Thus, mistakes in calling code ran may raise ugly exceptions here, like ArrayIndexOutOfBoundsException, etc .

The multi-byte primitive input methods (readUShortLE(), readIntLE() and readLongLE()) have corresponding 'spanning read' methods which (when required) perform a read across the block boundary. These spanning read methods take the previous DataInputBlock as a parameter. Reads of larger amounts of data (into byte array buffers) must be managed by the caller since these could conceivably involve more than two blocks.

Author:
Josh Micich

  • Method Summary

    Modifier and Type Method Description
    int available()  
    void readFully​(byte[] buf, int off, int len)
    Reads len bytes from this block into the supplied buffer.
    int readIntLE()
    Reads an int which was encoded in little endian format.
    int readIntLE​(DataInputBlock prevBlock, int prevBlockAvailable)
    Reads an int which spans the end of prevBlock and the start of this block.
    long readLongLE()
    Reads a long which was encoded in little endian format.
    long readLongLE​(DataInputBlock prevBlock, int prevBlockAvailable)
    Reads a long which spans the end of prevBlock and the start of this block.
    int readUByte()  
    int readUShortLE()
    Reads a short which was encoded in little endian format.
    int readUShortLE​(DataInputBlock prevBlock)
    Reads a short which spans the end of prevBlock and the start of this block.

    Methods inherited from class java.lang.Object

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

  • Method Details

    • available

      public int available()

    • readUByte

      public int readUByte()

    • readUShortLE

      public int readUShortLE()
      Reads a short which was encoded in little endian format.

    • readUShortLE

      public int readUShortLE​(DataInputBlock prevBlock)
      Reads a short which spans the end of prevBlock and the start of this block.

    • readIntLE

      public int readIntLE()
      Reads an int which was encoded in little endian format.

    • readIntLE

      public int readIntLE​(DataInputBlock prevBlock, int prevBlockAvailable)
      Reads an int which spans the end of prevBlock and the start of this block.

    • readLongLE

      public long readLongLE()
      Reads a long which was encoded in little endian format.

    • readLongLE

      public long readLongLE​(DataInputBlock prevBlock, int prevBlockAvailable)
      Reads a long which spans the end of prevBlock and the start of this block.

    • readFully

      public void readFully​(byte[] buf, int off, int len)
      Reads len bytes from this block into the supplied buffer.