Package org.geotools.data.shapefile.dbf

Class DbaseFileHeader

Object
DbaseFileHeader
public class DbaseFileHeader extends Object
Class to represent the header of a Dbase III file. Creation date: (5/15/2001 5:15:30 PM)

  • Field Details

    • MILLIS_SINCE_4713

      public static long MILLIS_SINCE_4713
      Returns the number of millis at January 1st 4713 BC

      Calendar refCal = (Calendar) new GregorianCalendar(TimeZone.getTimeZone("UTC")); refCal.set(Calendar.ERA, GregorianCalendar.BC); refCal.set(Calendar.YEAR, 4713); refCal.set(Calendar.MONTH, Calendar.JANUARY); refCal.set(Calendar.DAY_OF_MONTH, 1); refCal.set(Calendar.HOUR, 12); refCal.set(Calendar.MINUTE, 0); refCal.set(Calendar.SECOND, 0); refCal.set(Calendar.MILLISECOND, 0); MILLIS_SINCE_4713 = refCal.getTimeInMillis() - 43200000L; //(43200000L: 12 hour correction factor taken from DBFViewer2000)

  • Constructor Details

    • DbaseFileHeader

      public DbaseFileHeader()

    • DbaseFileHeader

      public DbaseFileHeader(Charset charset)

  • Method Details

    • getFieldClass

      public Class<?> getFieldClass(int i)
      Determine the most appropriate Java Class for representing the data in the field. 
       All packages are java.lang unless otherwise specified.
 C (Character) -> String
 N (Numeric)   -> Integer or Long or Double (depends on field's decimal count and fieldLength)
 F (Floating)  -> Double
 L (Logical)   -> Boolean
 D (Date)      -> java.util.Date (Without time)
      Parameters:
      i - The index of the field, from 0 to getNumFields() - 1 .
      Returns:
      A Class which closely represents the dbase field type.

    • addColumn

      public void addColumn(String inFieldName, char inFieldType, int inFieldLength, int inDecimalCount) throws DbaseFileException
      Add a column to this DbaseFileHeader. The type is one of (C N L or D) character, number, logical(true/false), or date. The Field length is the total length in bytes reserved for this column. The decimal count only applies to numbers(N), and floating point values (F), and refers to the number of characters to reserve after the decimal point. Don't expect miracles from this... 
       Field Type MaxLength
 ---------- ---------
 C          254
 D          8
      Parameters:
      inFieldName - The name of the new field, must be less than 10 characters or it gets truncated.
      inFieldType - A character representing the dBase field, ( see above ). Case insensitive.
      inFieldLength - The length of the field, in bytes ( see above )
      inDecimalCount - For numeric fields, the number of decimal places to track.
      Throws:
      DbaseFileException - If the type is not recognized.

    • removeColumn

      public int removeColumn(String inFieldName)
      Remove a column from this DbaseFileHeader.
      Parameters:
      inFieldName - The name of the field, will ignore case and trim.
      Returns:
      index of the removed column, -1 if no found

    • getFieldLength

      public int getFieldLength(int inIndex)
      Returns the field length in bytes.
      Parameters:
      inIndex - The field index.
      Returns:
      The length in bytes.

    • getFieldDecimalCount

      public int getFieldDecimalCount(int inIndex)
      Get the decimal count of this field.
      Parameters:
      inIndex - The field index.
      Returns:
      The decimal count.

    • getFieldName

      public String getFieldName(int inIndex)
      Get the field name.
      Parameters:
      inIndex - The field index.
      Returns:
      The name of the field.

    • getFieldType

      public char getFieldType(int inIndex)
      Get the character class of the field.
      Parameters:
      inIndex - The field index.
      Returns:
      The dbase character representing this field.

    • getLastUpdateDate

      public Date getLastUpdateDate()
      Get the date this file was last updated.
      Returns:
      The Date last modified.

    • getNumFields

      public int getNumFields()
      Return the number of fields in the records.
      Returns:
      The number of fields in this table.

    • getNumRecords

      public int getNumRecords()
      Return the number of records in the file
      Returns:
      The number of records in this table.

    • getRecordLength

      public int getRecordLength()
      Get the length of the records in bytes.
      Returns:
      The number of bytes per record.

    • getHeaderLength

      public int getHeaderLength()
      Get the length of the header
      Returns:
      The length of the header in bytes.

    • readHeader

      public void readHeader(ReadableByteChannel channel) throws IOException
      Read the header data from the DBF file.
      Parameters:
      channel - A readable byte channel. If you have an InputStream you need to use, you can call java.nio.Channels.getChannel(InputStream in).
      Throws:
      IOException - If errors occur while reading.

    • readHeader

      public void readHeader(ByteBuffer in) throws IOException
      Read the header data from the DBF file.
      Parameters:
      in - The ByteBuffer to read the header from
      Throws:
      IOException - If errors occur while reading.

    • getLargestFieldSize

      public int getLargestFieldSize()
      Get the largest field size of this table.
      Returns:
      The largest field size in bytes.

    • setNumRecords

      public void setNumRecords(int inNumRecords)
      Set the number of records in the file
      Parameters:
      inNumRecords - The number of records.

    • writeHeader

      public void writeHeader(WritableByteChannel out) throws IOException
      Write the header data to the DBF file.
      Parameters:
      out - A channel to write to. If you have an OutputStream you can obtain the correct channel by using java.nio.Channels.newChannel(OutputStream out).
      Throws:
      IOException - If errors occur.

    • toString

      public String toString()
      Get a simple representation of this header.
      Overrides:
      toString in class Object
      Returns:
      A String representing the state of the header.

    • getLengthForRecords

      public long getLengthForRecords(int records)
      Returns the expected file size for the given number of records in the file