org.apache.jorphan.collections

Class Data

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.

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
getColumnAsObjectArray(String columnName)
This method will retrieve every entry in a certain column.
Object
getColumnValue(String column)
Gets the value in the current row of the given column.
Object
getColumnValue(int column)
Gets the value in the current row of the given column.
Object
getColumnValue(int column, int row)
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(String colName, Object value)
Sets the data for every row in the column.
void
setColumnData(int col, List data)
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()

Constructor Details

Data

public Data()
Constructor - takes no arguments.

Method Details

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.

addHeader

public void addHeader(String s)
Adds a header name to the Data object.
Parameters:
s - name of header.

addRow

public void addRow()

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

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.

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.

getColumnAsObjectArray

public List 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.

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)

getCurrentPos

public int getCurrentPos()
Get the number of the current row.
Returns:
integer representing the current row

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.

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

getHeaderCount

public int getHeaderCount()

getHeaders

public String[] getHeaders()
Returns a String array of the column headers.
Returns:
array of strings of the column headers.

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.

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.

removeColumn

public void removeColumn(int col)

removeRow

public void removeRow()
Removes the current row.

removeRow

public void removeRow(int index)

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.

reset

public void reset()
Resets the current position of the data set to just before the first element.

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)

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.

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.

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.

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

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.

size

public int size()
Gets the number of rows in the Data object.
Returns:
number of rows in Data object.

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.

toString

public String toString()

Copyright © 1998-2010 Apache Software Foundation. All Rights Reserved.