io.jenetics.xml.stream

Interface Writer<T>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Writer<T>

XML writer interface, used for writing objects in XML format. The following XML will show the marshaled representation of an IntegerChromosome.

 
 <int-chromosome length="3">
     <min>-2147483648</min>
     <max>2147483647</max>
     <alleles>
         <allele>-1878762439</allele>
         <allele>-957346595</allele>
         <allele>-88668137</allele>
     </alleles>
 </int-chromosome>
 

The XML has been written by the following Writer definition.

final Writer<IntegerChromosome> writer = elem("int-chromosome", attr("length").map(ch -> ch.length()), elem("min", Writer.<Integer>text().map(ch -> ch.getMin())), elem("max", Writer.<Integer>text().map(ch -> ch.getMax())), elem("alleles", elems("allele", Writer.<Integer>text()) .map(ch -> ch.toSeq().map(g -> g.getAllele())) ) );

How to write the XML writing is shown by the next code snippet.

final IntegerChromosome ch = IntegerChromosome.of(MIN_VALUE, MAX_VALUE, 3); try (AutoCloseableXMLStreamWriter xml = XML.writer(out, indent)) { write(ch, xml); }

Since:

3.9

Version:

3.9

Author:

Franz Wilhelmstötter

Method Summary

Modifier and Type	Method and Description
static <T> Writer<T>	attr(String name) Writes the attribute with the given name to the current outer element.
static <T> Writer<T>	attr(String name, Object value) Writes the attribute with the given name and a constant value to the current outer element.
static <T> Writer<T>	doc(Writer<? super T> writer) Adds a XML prolog element written by the given writer.
static <T> Writer<T>	elem(String name, Writer<? super T>... children) Create a new Writer, which writes a XML element with the given name and writes the given children into it.
static <T> Writer<Iterable<T>>	elems(String name, Writer<? super T> writer) Creates a new Writer, which writes the given children as sub-elements, defined by the given childWriter.
static <T> Writer<Iterable<T>>	elems(Writer<? super T> writer) Creates a new Writer, which writes the given children as sub-elements, defined by the given childWriter.
default <B> Writer<B>	map(Function<? super B,? extends T> mapper) Maps this writer to a different base type.
static <T> Writer<T>	text() Create a new text Writer, which writes the given data as string to the outer element.
void	write(XMLStreamWriter xml, T data) Write the data of type T to the given XML stream writer.

Method Detail

write

void write(XMLStreamWriter xml,
           T data)
    throws XMLStreamException

Write the data of type T to the given XML stream writer.

Parameters:

xml - the underlying XMLStreamWriter, where the value is written to

data - the value to write

Throws:

XMLStreamException - if writing the data fails

NullPointerException - if one of the arguments is null

map

default <B> Writer<B> map(Function<? super B,? extends T> mapper)

Maps this writer to a different base type. Mapping to a different data type is necessary when you are going to write sub-objects of your basic data type T. E.g. the chromosome length or the min and max value of an IntegerChromosome.

Type Parameters:

B - the new data type of returned writer

Parameters:

mapper - the mapper function

Returns:

a writer with changed type

attr

static <T> Writer<T> attr(String name)

Writes the attribute with the given name to the current outer element.

final Writer<String> writer1 = elem("element", attr("attribute"));

Type Parameters:

T - the writer base type

Parameters:

name - the attribute name

Returns:

a new writer instance

Throws:

NullPointerException - if the attribute name is null

See Also:

attr(String, Object)

attr

static <T> Writer<T> attr(String name,
                          Object value)

Writes the attribute with the given name and a constant value to the current outer element.

final Writer<MyObject> = elem("element", attr("version", "1.0"));

Type Parameters:

T - the writer base type

Parameters:

name - the attribute name

value - the attribute value

Returns:

a new writer instance

Throws:

NullPointerException - if one of the name is null

elem

@SafeVarargs
static <T> Writer<T> elem(String name,
                                       Writer<? super T>... children)

Create a new Writer, which writes a XML element with the given name and writes the given children into it.

Type Parameters:

T - the writer base type

Parameters:

name - the root element name

children - the XML child elements

Returns:

a new writer instance

Throws:

NullPointerException - if one of the arguments is null

text

static <T> Writer<T> text()

Create a new text Writer, which writes the given data as string to the outer element.

Type Parameters:

T - the data type, which is written as string to the outer element

Returns:

a new text writer

elems

static <T> Writer<Iterable<T>> elems(String name,
                                     Writer<? super T> writer)

Creates a new Writer, which writes the given children as sub-elements, defined by the given childWriter.

Type Parameters:

T - the writer base type

Parameters:

name - the enclosing element name used for each data value

writer - the sub-element writer

Returns:

a new writer instance

Throws:

NullPointerException - if one of the arguments is null

elems

static <T> Writer<Iterable<T>> elems(Writer<? super T> writer)

Creates a new Writer, which writes the given children as sub-elements, defined by the given childWriter.

Type Parameters:

T - the writer base type

Parameters:

writer - the sub-element writer

Returns:

a new writer instance

Throws:

NullPointerException - if one of the arguments is null

doc

static <T> Writer<T> doc(Writer<? super T> writer)

Adds a XML prolog element written by the given writer. The default values for encoding and version is set to "UTF-8" and "1.0", respectively.

 
 <?xml version="1.0" encoding="UTF-8"?>
 

Type Parameters:

T - the writer data type

Parameters:

writer - the root element writer

Returns:

a new writer instance