com.opencsv.bean

Interface FieldMap<I,K extends Comparable<K>,C extends ComplexFieldMapEntry<I,K,T>,T>

Type Parameters:

I - The initializer type used to build the many-to-one mapping

K - Type of the field identifier (key)

C - Type of the ComplexFieldMapEntry used. This is specified as a parameter so we can provide type safety and polymorphism through a generic interface on the one hand, and still extend specific implementations with methods needed for that type of complex mapping without having to add every such method to the generic interface.

T - The type of the bean

All Known Implementing Classes:

AbstractFieldMap, FieldMapByName, FieldMapByPosition

public interface FieldMap<I,K extends Comparable<K>,C extends ComplexFieldMapEntry<I,K,T>,T>

Defines the basic characteristics of a map between field identifiers and their associated BeanFields. Such a mapping requires a method of matching multiple fields. This method will require data to initialize itself. Such a mapping also requires a key to index the BeanField that is to be provided for a match.

Since:

4.2

Author:

Andrew Rucker Jones

Method Summary

Modifier and Type	Method and Description
String[]	generateHeader(T bean) This method generates a header that can be used for writing beans of the type provided back to a file.
BeanField<T,K>	get(K key) Gets the BeanField associated with this key.
BeanField<T,K>	put(K key, BeanField<T,K> value) Associates the given BeanField with the given key.
void	putComplex(I initializer, BeanField<T,K> value) Adds a BeanField to this map indexed by the data in initializer.
void	setErrorLocale(Locale errorLocale) Sets the locale to be used for error messages.
Collection<BeanField<T,K>>	values() Provides all values currently in the map.

Method Detail

generateHeader

String[] generateHeader(T bean)
                 throws CsvRequiredFieldEmptyException

This method generates a header that can be used for writing beans of the type provided back to a file. Whether or not this generated header is used is decided by the MappingStrategy in use. The ordering of the headers should be carefully considered by the implementing class.

Parameters:

bean - One perfect, shining example of how the bean to be written should look. The most crucial thing is, for fields that result from joining multiple fields on reading and thus need to be split on writing, the MultiValuedMap in question must have the complete structure of the header to be generated, even if some values are empty.

Returns:

An array of header names for the output file

Throws:

CsvRequiredFieldEmptyException - If a required header is missing while attempting to write. Since every other header is hard-wired through the bean fields and their associated annotations, this can only happen with multi-valued fields.

get

BeanField<T,K> get(K key)

Gets the BeanField associated with this key. If a key could possibly match both a regular, simple key (one added with put(Comparable, BeanField)), and a complex key (one added with putComplex(java.lang.Object, com.opencsv.bean.BeanField)), the simple key is always matched. If a key could match more than one complex key, the return value is undefined.

Parameters:

key - The key under which to search for a BeanField

Returns:

The BeanField found, or null if none is present

put

BeanField<T,K> put(K key,
                   BeanField<T,K> value)

Associates the given BeanField with the given key.

Parameters:

key - The key under which to index the provided BeanField

value - The BeanField to be indexed

Returns:

If there was a value previously associated with this key, it is returned

putComplex

void putComplex(I initializer,
                BeanField<T,K> value)

Adds a BeanField to this map indexed by the data in initializer. This is what makes this map special: It allows one to define characteristics of a method to match multiple keys.

Parameters:

initializer - Whatever data the implementation needs to match multiple keys

value - The BeanField that is to be returned on a later match

setErrorLocale

void setErrorLocale(Locale errorLocale)

Sets the locale to be used for error messages.

Parameters:

errorLocale - The locale to be used for error messages

values

Collection<BeanField<T,K>> values()

Provides all values currently in the map.

Returns:

The values in the map