Package uk.ac.starlink.table

Class AbstractStarTable

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static int checkedLongToInt​(long lval)
      Convenience method to get an int value from a long.
      void close()
      The AbstractStarTable implementation of this method does nothing.
      java.lang.Object getCell​(long irow, int icol)
      The AbstractStarTable implementation of this method throws an UnsupportedOperationException, since unless otherwise provided there is no random access.
      java.util.List<ValueInfo> getColumnAuxDataInfos()
      Goes through the table columns (ColumnInfo objects) and picks out all the AuxData items which exist, generalising where necessary and returning a union of them in alphabetical order by name.
      abstract int getColumnCount()
      Returns the number of columns in this table.
      abstract ColumnInfo getColumnInfo​(int icol)
      Returns the object describing the data in a given column.
      java.lang.String getName()
      Returns the name of this table, if it has one.
      java.util.List<DescribedValue> getParameters()
      Returns a list of table parameters, that is metadata items which pertain to the entire table.
      java.lang.Object[] getRow​(long irow)
      The AbstractStarTable implementation of this method constructs a row by repeated invocation of getCell(long, int).
      RowAccess getRowAccess()
      Returns an object which can provide random access to this table's data, if random access is implemented.
      abstract long getRowCount()
      Returns the number of rows in this table, if known.
      abstract RowSequence getRowSequence()
      Returns an object which can iterate over all the rows in the table sequentially.
      RowSplittable getRowSplittable()
      Returns a default splittable which relies on table random access if available, or otherwise provides only sequential access (no splits).
      java.net.URL getURL()
      Returns the URL of this table, if it has one.
      boolean isRandom()
      The AbstractStarTable implementation of this method returns false.
      void setName​(java.lang.String name)
      Sets the name for this table.
      void setParameters​(java.util.List<DescribedValue> parameters)
      Sets the list of table parameters, that is items which pertain to the entire table.
      void setURL​(java.net.URL url)
      Sets the URL for this table.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • AbstractStarTable

        public AbstractStarTable()

    • Method Detail

      • getColumnAuxDataInfos

        public java.util.List<ValueInfo> getColumnAuxDataInfos()
        Goes through the table columns (ColumnInfo objects) and picks out all the AuxData items which exist, generalising where necessary and returning a union of them in alphabetical order by name. Subclasses should override this if they can do better, for instance providing an order for the keys.
        Specified by:
        getColumnAuxDataInfos in interface StarTable
        Returns:
        a list of all the auxiliary metadata ValueInfo items which in fact crop up in column metadata
        See Also:
        DefaultValueInfo.getAuxData()

      • getParameters

        public java.util.List<DescribedValue> getParameters()
        Description copied from interface: StarTable
        Returns a list of table parameters, that is metadata items which pertain to the entire table.
        Specified by:
        getParameters in interface StarTable
        Returns:
        a List of DescribedValue objects constituting table-wide metadata not covered elsewhere in this interface

      • setParameters

        public void setParameters​(java.util.List<DescribedValue> parameters)
        Sets the list of table parameters, that is items which pertain to the entire table. Each element of the provided list parameters should be a DescribedValue object.
        Parameters:
        parameters - a List of DescribedValues pertaining to this table

      • getName

        public java.lang.String getName()
        Description copied from interface: StarTable
        Returns the name of this table, if it has one. The meaning of the name is not defined, but it will typically be a short string of text indicating the identity of this table.
        Specified by:
        getName in interface StarTable
        Returns:
        a name for this table, or null if no suitable one exists

      • setName

        public void setName​(java.lang.String name)
        Sets the name for this table.
        Specified by:
        setName in interface StarTable
        Parameters:
        name - the table name - may be null

      • getURL

        public java.net.URL getURL()
        Description copied from interface: StarTable
        Returns the URL of this table, if it has one. A non-null return from this method indicates that this table is in some sense persistent.
        Specified by:
        getURL in interface StarTable
        Returns:
        the URL of this table, or null if none is known

      • setURL

        public void setURL​(java.net.URL url)
        Sets the URL for this table.
        Specified by:
        setURL in interface StarTable
        Parameters:
        url - the URL where this table lives - may be null

      • checkedLongToInt

        public static int checkedLongToInt​(long lval)
        Convenience method to get an int value from a long. Invokes Tables.checkedLongToInt(long).

      • isRandom

        public boolean isRandom()
        The AbstractStarTable implementation of this method returns false.
        Specified by:
        isRandom in interface StarTable
        Returns:
        true if table random access methods are available

      • getRowAccess

        public RowAccess getRowAccess()
                       throws java.io.IOException
        Description copied from interface: StarTable
        Returns an object which can provide random access to this table's data, if random access is implemented. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
        Specified by:
        getRowAccess in interface StarTable
        Returns:
        new RowAccess
        Throws:
        java.io.IOException - if there is an error setting up access

      • getRowSplittable

        public RowSplittable getRowSplittable()
                               throws java.io.IOException
        Returns a default splittable which relies on table random access if available, or otherwise provides only sequential access (no splits).

        It is often possible to provide a better implementation than this.

        Specified by:
        getRowSplittable in interface StarTable
        Returns:
        Tables.getDefaultRowSplittable(this)
        Throws:
        java.io.IOException
        See Also:
        RowRunner

      • getCell

        public java.lang.Object getCell​(long irow,
                                int icol)
                         throws java.io.IOException
        The AbstractStarTable implementation of this method throws an UnsupportedOperationException, since unless otherwise provided there is no random access.
        Specified by:
        getCell in interface StarTable
        Parameters:
        irow - the index of the cell's row
        icol - the index of the cell's column
        Returns:
        the contents of this cell
        Throws:
        java.io.IOException - if there is an error reading the data

      • getRow

        public java.lang.Object[] getRow​(long irow)
                          throws java.io.IOException
        The AbstractStarTable implementation of this method constructs a row by repeated invocation of getCell(long, int).
        Specified by:
        getRow in interface StarTable
        Parameters:
        irow - the index of the row to retrieve
        Returns:
        an array of the objects in each cell in row irow
        Throws:
        java.io.IOException - if there is an error reading the data

      • close

        public void close()
           throws java.io.IOException
        The AbstractStarTable implementation of this method does nothing.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in interface StarTable
        Throws:
        java.io.IOException

      • getColumnInfo

        public abstract ColumnInfo getColumnInfo​(int icol)
        Description copied from interface: StarTable
        Returns the object describing the data in a given column.
        Specified by:
        getColumnInfo in interface StarTable
        Parameters:
        icol - the column for which header information is required
        Returns:
        a ValueInfo object for column icol

      • getColumnCount

        public abstract int getColumnCount()
        Description copied from interface: StarTable
        Returns the number of columns in this table.
        Specified by:
        getColumnCount in interface StarTable
        Returns:
        the number of columns

      • getRowCount

        public abstract long getRowCount()
        Description copied from interface: StarTable
        Returns the number of rows in this table, if known. If the number of rows cannot be (easily) determined, a value of -1 will be returned.
        Specified by:
        getRowCount in interface StarTable
        Returns:
        the number of rows, or -1

      • getRowSequence

        public abstract RowSequence getRowSequence()
                                    throws java.io.IOException
        Description copied from interface: StarTable
        Returns an object which can iterate over all the rows in the table sequentially. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
        Specified by:
        getRowSequence in interface StarTable
        Returns:
        new RowSequence
        Throws:
        java.io.IOException - if there is an error providing access