org.supercsv.util

Class Util

java.lang.Object

org.supercsv.util.Util

public final class Util
extends Object

Useful utility methods.

Author:

Kasper B. Graversen, James Bassett

Method Summary

Modifier and Type	Method and Description
static void	executeCellProcessors(List<Object> destination, List<?> source, CellProcessor[] processors, int lineNo, int rowNo) Processes each element in the source List (using the corresponding processor chain in the processors array) and adds it to the destination List.
static <T> void	filterListToMap(Map<String,T> destinationMap, String[] nameMapping, List<? extends T> sourceList) Converts a List to a Map using the elements of the nameMapping array as the keys of the Map.
static List<Object>	filterMapToList(Map<String,?> map, String[] nameMapping) Returns a List of all of the values in the Map whose key matches an entry in the nameMapping array.
static Object[]	filterMapToObjectArray(Map<String,?> values, String[] nameMapping) Converts a Map to an array of objects, adding only those entries whose key is in the nameMapping array.
static String[]	objectArrayToStringArray(Object[] objectArray) Converts an Object array to a String array (null-safe), by calling toString() on each element.
static String[]	objectListToStringArray(List<?> objectList) Converts an List<Object> to a String array (null-safe), by calling toString() on each element.

Methods inherited from class java.lang.Object

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

Method Detail

executeCellProcessors

public static void executeCellProcessors(List<Object> destination,
                                         List<?> source,
                                         CellProcessor[] processors,
                                         int lineNo,
                                         int rowNo)

Processes each element in the source List (using the corresponding processor chain in the processors array) and adds it to the destination List. A null CellProcessor in the array indicates that no processing is required and the element should be added as-is.

Parameters:

destination - the List to add the processed elements to (which is cleared before it's populated)

source - the List of source elements to be processed

processors - the array of CellProcessors used to process each element. The number of elements in this array must match the size of the source List. A null CellProcessor in this array indicates that no processing is required and the element should be added as-is.

lineNo - the current line number

rowNo - the current row number

Throws:

NullPointerException - if destination, source or processors is null

SuperCsvConstraintViolationException - if a CellProcessor constraint failed

SuperCsvException - if source.size() != processors.length, or CellProcessor execution failed

filterListToMap

public static <T> void filterListToMap(Map<String,T> destinationMap,
                                       String[] nameMapping,
                                       List<? extends T> sourceList)

Converts a List to a Map using the elements of the nameMapping array as the keys of the Map.

Type Parameters:

T - the type of the values in the map

Parameters:

destinationMap - the destination Map (which is cleared before it's populated)

nameMapping - the keys of the Map (corresponding with the elements in the sourceList). Cannot contain duplicates.

sourceList - the List to convert

Throws:

NullPointerException - if destinationMap, nameMapping or sourceList are null

SuperCsvException - if nameMapping and sourceList are not the same size

filterMapToList

public static List<Object> filterMapToList(Map<String,?> map,
                                           String[] nameMapping)

Returns a List of all of the values in the Map whose key matches an entry in the nameMapping array.

Parameters:

map - the map

nameMapping - the keys of the Map values to add to the List

Returns:

a List of all of the values in the Map whose key matches an entry in the nameMapping array

Throws:

NullPointerException - if map or nameMapping is null

filterMapToObjectArray

public static Object[] filterMapToObjectArray(Map<String,?> values,
                                              String[] nameMapping)

Converts a Map to an array of objects, adding only those entries whose key is in the nameMapping array.

Parameters:

values - the Map of values to convert

nameMapping - the keys to extract from the Map (elements in the target array will be added in this order)

Returns:

the array of Objects

Throws:

NullPointerException - if values or nameMapping is null

objectArrayToStringArray

public static String[] objectArrayToStringArray(Object[] objectArray)

Converts an Object array to a String array (null-safe), by calling toString() on each element.

Parameters:

objectArray - the Object array

Returns:

the String array, or null if objectArray is null

objectListToStringArray

public static String[] objectListToStringArray(List<?> objectList)

Converts an List<Object> to a String array (null-safe), by calling toString() on each element.

Parameters:

objectList - the List

Returns:

the String array, or null if objectList is null