org.apache.jorphan.collections
Class Data

java.lang.Object
  org.apache.jorphan.collections.Data

All Implemented Interfaces:

Serializable

public class Data
extends Object
implements Serializable

Use this class to store database-like data. This class uses rows and columns to organize its data. It has some convenience methods that allow fast loading and retrieval of the data into and out of string arrays. It is also handy for reading CSV files. WARNING: the class assumes that column names are unique, but does not enforce this.

See Also:

Serialized Form

Constructor Summary

Data()
Constructor - takes no arguments.

Method Summary

void	addColumnValue(String column, Object value) Adds a value into the Data set at the current row, using a column name to find the column in which to insert the new value.
void	addHeader(String s) Adds a header name to the Data object.
void	addRow()
void	append(Data d) Adds the rows of the given Data object to this Data object.
int	findValue(String column, Object value) Returns the row number where a certain value is.
String[]	getColumn(String columnName) This method will retrieve every entry in a certain column.
List<Object>	getColumnAsObjectArray(String columnName) This method will retrieve every entry in a certain column.
Object	getColumnValue(int column) Gets the value in the current row of the given column.
Object	getColumnValue(int column, int row)
Object	getColumnValue(String column) Gets the value in the current row of the given column.
int	getCurrentPos() Get the number of the current row.
String[]	getDataAsText() Returns all the data in the Data set as an array of strings.
static Data	getDataFromResultSet(ResultSet rs) Gets a Data object from a ResultSet.
int	getHeaderCount()
String[]	getHeaders() Returns a String array of the column headers.
boolean	hasHeader(String column) Checks to see if a column exists in the Data object.
boolean	next() Sets the current position of the Data set to the next row.
boolean	previous() Sets the current position of the Data set to the previous row.
void	removeColumn(int col)
void	removeRow() Removes the current row.
void	removeRow(int index)
void	replaceHeader(String oldHeader, String newHeader) Replaces the given header name with a new header name.
void	reset() Resets the current position of the data set to just before the first element.
void	setColumnData(int col, List<?> data)
void	setColumnData(String colName, Object value) Sets the data for every row in the column.
void	setColumnValue(String column, Object value) Sets the value in the Data set at the current row, using a column name to find the column in which to insert the new value.
void	setCurrentPos(int r) Sets the current pos.
void	setData(String[] contents, String delimiter) Use this method to set the entire data set.
void	setHeaders(String[] h) Sets the headers for the data set.
void	setLine(String[] line) Sets a row of data using an array of strings as input.
void	setLine(String[] line, String deflt) Sets a row of data using an array of strings as input.
int	size() Gets the number of rows in the Data object.
void	sort(String column, boolean asc) Sorts the data using a given row as the sorting criteria.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Data

public Data()

Constructor - takes no arguments.

Method Detail

replaceHeader

public void replaceHeader(String oldHeader,
                          String newHeader)

Replaces the given header name with a new header name.

Parameters:

oldHeader - Old header name.

newHeader - New header name.

append

public void append(Data d)

Adds the rows of the given Data object to this Data object.

Parameters:

d - data object to be appended to this one

getCurrentPos

public int getCurrentPos()

Get the number of the current row.

Returns:

integer representing the current row

removeRow

public void removeRow()

Removes the current row.

removeRow

public void removeRow(int index)

addRow

public void addRow()

setCurrentPos

public void setCurrentPos(int r)

Sets the current pos. If value sent to method is not a valid number, the current position is set to one higher than the maximum.

Parameters:

r - position to set to.

sort

public void sort(String column,
                 boolean asc)

Sorts the data using a given row as the sorting criteria. A boolean value indicates whether to sort ascending or descending.

Parameters:

column - name of column to use as sorting criteria.

asc - boolean value indicating whether to sort ascending or descending. True for asc, false for desc. Currently this feature is not enabled and all sorts are asc.

size

public int size()

Gets the number of rows in the Data object.

Returns:

number of rows in Data object.

addColumnValue

public void addColumnValue(String column,
                           Object value)

Adds a value into the Data set at the current row, using a column name to find the column in which to insert the new value.

Parameters:

column - the name of the column to set.

value - value to set into column.

findValue

public int findValue(String column,
                     Object value)

Returns the row number where a certain value is.

Parameters:

column - column to be searched for value.

value - object in Search of.

Returns:

row # where value exists.

setColumnValue

public void setColumnValue(String column,
                           Object value)

Sets the value in the Data set at the current row, using a column name to find the column in which to insert the new value.

Parameters:

column - the name of the column to set.

value - value to set into column.

hasHeader

public boolean hasHeader(String column)

Checks to see if a column exists in the Data object.

Parameters:

column - Name of column header to check for.

Returns:

True or False depending on whether the column exists.

next

public boolean next()

Sets the current position of the Data set to the next row.

Returns:

True if there is another row. False if there are no more rows.

getDataFromResultSet

public static Data getDataFromResultSet(ResultSet rs)
                                 throws SQLException

Gets a Data object from a ResultSet.

Parameters:

rs - ResultSet passed in from a database query

Returns:

a Data object

Throws:

SQLException

previous

public boolean previous()

Sets the current position of the Data set to the previous row.

Returns:

True if there is another row. False if there are no more rows.

reset

public void reset()

Resets the current position of the data set to just before the first element.

getColumnValue

public Object getColumnValue(String column)

Gets the value in the current row of the given column.

Parameters:

column - name of the column.

Returns:

an Object which holds the value of the column.

getColumnValue

public Object getColumnValue(int column)

Gets the value in the current row of the given column.

Parameters:

column - index of the column (starts at 0).

Returns:

an Object which holds the value of the column.

getColumnValue

public Object getColumnValue(int column,
                             int row)

removeColumn

public void removeColumn(int col)

setHeaders

public void setHeaders(String[] h)

Sets the headers for the data set. Each header represents a column of data. Each row's data can be gotten with the column header name, which will always be a string.

Parameters:

h - array of strings representing the column headers. these must be distinct - duplicates will cause incorrect behaviour

getHeaders

public String[] getHeaders()

Returns a String array of the column headers.

Returns:

array of strings of the column headers.

getHeaderCount

public int getHeaderCount()

getColumnAsObjectArray

public List<Object> getColumnAsObjectArray(String columnName)

This method will retrieve every entry in a certain column. It returns an array of Objects from the column.

Parameters:

columnName - name of the column.

Returns:

array of Objects representing the data.

getColumn

public String[] getColumn(String columnName)

This method will retrieve every entry in a certain column. It returns an array of strings from the column. Even if the data are not strings, they will be returned as strings in this method.

Parameters:

columnName - name of the column.

Returns:

array of Strings representing the data.

setData

public void setData(String[] contents,
                    String delimiter)

Use this method to set the entire data set. It takes an array of strings. It uses the first row as the headers, and the next rows as the data elements. Delimiter represents the delimiting character(s) that separate each item in a data row.

Parameters:

contents - array of strings, the first element is a list of the column headers, the next elements each represent a single row of data.

delimiter - the delimiter character that separates columns within the string array.

setColumnData

public void setColumnData(String colName,
                          Object value)

Sets the data for every row in the column.

setColumnData

public void setColumnData(int col,
                          List<?> data)

addHeader

public void addHeader(String s)

Adds a header name to the Data object.

Parameters:

s - name of header.

setLine

public void setLine(String[] line)

Sets a row of data using an array of strings as input. Each value in the array represents a column's value in that row. Assumes the order will be the same order in which the headers were added to the data set.

Parameters:

line - array of strings representing column values.

setLine

public void setLine(String[] line,
                    String deflt)

Sets a row of data using an array of strings as input. Each value in the array represents a column's value in that row. Assumes the order will be the same order in which the headers were added to the data set.

Parameters:

line - array of strings representing column values.

deflt - default value to be placed in data if line is not as long as headers.

getDataAsText

public String[] getDataAsText()

Returns all the data in the Data set as an array of strings. Each array gives a row of data, each column separated by tabs.

Returns:

array of strings.

toString

public String toString()

Overrides:

toString in class Object