com.topcoder.file.split
Class Metadata

java.lang.Object
  com.topcoder.file.split.Metadata

public final class Metadata
extends java.lang.Object

This is a final class for encapsulating metadata information used by the file splitter and joiner components. It consists of data members for the information stored in the header, and has methods for writing itself to an output stream and initializing itself by reading metadata from an input stream.

The following is an excerpt of the metadata header format:

The first split file also contains a header with metadata:

• Signature identifying this as a split file: the four character sequence "SPLT" encoded with UTF-8 encoding (four bytes)
• Major and minor format version (each one unsigned byte)
• Length of the rest of the header (unsigned big-endian four-byte value)
• Length of original file name (unsigned big-endian two-byte value)
• Original file name without path (UTF-8 encoding)
• Length of the split format string (unsigned big-endian two-byte value)
• Split format string (UTF-8 encoding)
• Number of split files (unsigned big-endian two-byte value)

Version:

1.0

Author:

npe

See Also:

FileSplitter, FileJoiner

Constructor Summary

Metadata()

Method Summary

short	getMajorVersion()
short	getMinorVersion()
int	getNumSplitFiles()
java.lang.String	getOriginalFileName()
long	getSize()
java.lang.String	getSplitFileFormatString()
void	read(java.io.InputStream is) Initializes this metadata object by reading a series of bytes from an input stream.
void	setMajorVersion(short majorVersion)
void	setMinorVersion(short minorVersion)
void	setNumSplitFiles(int numSplitFiles)
void	setOriginalFileName(java.lang.String originalFileName)
void	setSplitFileFormatString(java.lang.String splitFileFormatString)
void	write(java.io.OutputStream os) Writes this metadata object as a formatted series of bytes to an output stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

Metadata

public Metadata()

Method Detail

getMajorVersion

public short getMajorVersion()

Returns:

The metadata format major version number.

setMajorVersion

public void setMajorVersion(short majorVersion)

Parameters:

majorVersion - Sets the metadata format major version number.

getMinorVersion

public short getMinorVersion()

Returns:

The metadata format minor version number.

setMinorVersion

public void setMinorVersion(short minorVersion)

Parameters:

minorVersion - Sets the metadata format minor version number.

getOriginalFileName

public java.lang.String getOriginalFileName()

Returns:

The name of the original file.

setOriginalFileName

public void setOriginalFileName(java.lang.String originalFileName)

Parameters:

originalFileName - The name of the original file.

getSplitFileFormatString

public java.lang.String getSplitFileFormatString()

Returns:

The split file format string, which is the pattern used in a MessageFormat object. This string must contain {0} and {1} placeholders for formatting, although that is not validated here.

setSplitFileFormatString

public void setSplitFileFormatString(java.lang.String splitFileFormatString)

Parameters:

splitFileFormatString - The split file format string, which is the pattern used in a MessageFormat object. This string must contain {0} and {1} placeholders for formatting, although that is not validated here.

getNumSplitFiles

public int getNumSplitFiles()

Returns:

The number of split files.

setNumSplitFiles

public void setNumSplitFiles(int numSplitFiles)

Parameters:

numSplitFiles - The number of split files.

getSize

public long getSize()
             throws java.io.IOException

Returns:

The size of this metadata object in number of bytes. This value is the length of the signature and format version, plus the length of the remaining variable length data header.

Throws:

java.io.IOException

write

public void write(java.io.OutputStream os)
           throws java.io.IOException

Writes this metadata object as a formatted series of bytes to an output stream. The format is described in the JavaDocs for this class. This is used to write a header to the first split file.

Parameters:

os - The output stream to write the metadata header to.

Throws:

java.io.IOException - If an error occurs while writing the metadata header.

See Also:

FileSplitter

read

public void read(java.io.InputStream is)
          throws java.io.IOException,
                 InvalidSplitFileHeaderException

Initializes this metadata object by reading a series of bytes from an input stream. As the bytes are read they are validated to ensure that they conform to the metadata format, which is described in the JavaDocs for this class. This method is used to read metadata information from the first split file in order to join the split files together.

Parameters:

is - The input stream containing the metadata header.

Throws:

java.io.IOException - If an error occurs while reading the metadata.

InvalidSplitFileHeaderException - If the metadata read doesn't conform to the split file format.

See Also:

FileJoiner