ucar.nc2.write

Class NcmlWriter

java.lang.Object

ucar.nc2.write.NcmlWriter

public class NcmlWriter
extends java.lang.Object

Helper class to write NcML.

See Also:

NetcdfFile, https://www.unidata.ucar.edu/software/netcdf/ncml/

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NcmlWriter.WriteVariablesWithNamesPredicate Predicate that returns true for variables whose names are specified to the constructor.

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.function.Predicate<? super Variable>	writeAllVariablesPredicate Predicate that always returns true.
static java.util.function.Predicate<? super Variable>	writeCoordinateVariablesPredicate Predicate that returns true for variables that are coordinate variables.
static java.util.function.Predicate<? super Variable>	writeMetadataVariablesPredicate Predicate that returns true for variables that are metadata variables.
static java.util.function.Predicate<? super Variable>	writeNoVariablesPredicate Predicate that always returns false.

Constructor Summary

Constructors

Constructor and Description
NcmlWriter() Constructor with default values
NcmlWriter(org.jdom2.Namespace namespace, org.jdom2.output.Format xmlFormat, java.util.function.Predicate<? super Variable> writeValuesPredicate) Constructor allows you to set parameters.

Method Summary

Modifier and Type	Method and Description
org.jdom2.Namespace	getNamespace() Gets the XML namespace for the elements in the NcML.
java.util.function.Predicate<? super Variable>	getWriteValuesPredicate() Gets the predicate that will be applied to variables to determine wither their values should be written in addition to their metadata.
org.jdom2.output.Format	getXmlFormat() Gets the object that encapsulates XML formatting options.
org.jdom2.Element	makeAttributeElement(Attribute attribute)
org.jdom2.Element	makeDimensionElement(Dimension dim)
org.jdom2.Element	makeEnumTypedefElement(EnumTypedef etd)
org.jdom2.Element	makeExplicitNetcdfElement(NetcdfFile ncFile, java.lang.String location)
org.jdom2.Element	makeGroupElement(Group group)
org.jdom2.Element	makeNetcdfElement(NetcdfFile ncFile, java.lang.String location)
org.jdom2.Element	makeValuesElement(Variable variable, boolean allowRegular) Creates a <values> element from the variable's data.
org.jdom2.Element	makeVariableElement(Variable var, boolean showValues)
void	writeToFile(org.jdom2.Element elem, java.io.File outFile) Writes an NcML element to an output file.
void	writeToStream(org.jdom2.Element elem, java.io.OutputStream outStream) Writes an NcML element to an output stream.
java.lang.String	writeToString(org.jdom2.Element elem) Writes an NcML element to a string.
void	writeToWriter(org.jdom2.Element elem, java.io.Writer writer) Writes an NcML element to a Writer.

Methods inherited from class java.lang.Object

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

Field Detail

writeAllVariablesPredicate

public static final java.util.function.Predicate<? super Variable> writeAllVariablesPredicate

Predicate that always returns true.

writeCoordinateVariablesPredicate

public static final java.util.function.Predicate<? super Variable> writeCoordinateVariablesPredicate

Predicate that returns true for variables that are coordinate variables.

writeMetadataVariablesPredicate

public static final java.util.function.Predicate<? super Variable> writeMetadataVariablesPredicate

Predicate that returns true for variables that are metadata variables. For such variables, the data is not actually present in the file, so we must include it in the NcML. It could be synthesized (i.e. generated by an IOSP) or specified in a element of the input NcML.

writeNoVariablesPredicate

public static final java.util.function.Predicate<? super Variable> writeNoVariablesPredicate

Predicate that always returns false.

Constructor Detail

NcmlWriter

public NcmlWriter()

Constructor with default values

NcmlWriter

public NcmlWriter(@Nullable
                  org.jdom2.Namespace namespace,
                  @Nullable
                  org.jdom2.output.Format xmlFormat,
                  @Nullable
                  java.util.function.Predicate<? super Variable> writeValuesPredicate)

Constructor allows you to set parameters. Any parameters may be null for default.

Parameters:

namespace - if null use ncmlDefaultNamespace.

xmlFormat - if null, use Format.getPrettyFormat().setLineSeparator(LineSeparator.UNIX).

writeValuesPredicate - if null, write a Variable's values if Variable.isMetadata(). This determines whether values should be written or not. The values will be contained within a <values> element. By default, the predicate will be writeMetadataVariablesPredicate. There could be data loss if the values of metadata variables aren't included in the NcML, so we recommend that you always use it, possibly as part of a compound predicate. For example, suppose you wanted to print the values of metadata and coordinate variables:

        Predicate compoundPred =
        Predicates.or(writeMetadataVariablesPredicate, writeCoordinateVariablesPredicate);
        ncmlWriter.setWriteVariablesPredicate(compoundPred);
        

Method Detail

getNamespace

public org.jdom2.Namespace getNamespace()

Gets the XML namespace for the elements in the NcML. By default, it is ncmlDefaultNamespace.

Returns:

the XML namespace.

getWriteValuesPredicate

public java.util.function.Predicate<? super Variable> getWriteValuesPredicate()

Gets the predicate that will be applied to variables to determine wither their values should be written in addition to their metadata. The values will be contained within a <values> element.

Returns:

the predicate.

getXmlFormat

public org.jdom2.output.Format getXmlFormat()

Gets the object that encapsulates XML formatting options. By default, the format is pretty with UNIX line separators.

Returns:

the XML formatting options.

makeAttributeElement

public org.jdom2.Element makeAttributeElement(Attribute attribute)

makeDimensionElement

public org.jdom2.Element makeDimensionElement(Dimension dim)
                                       throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

makeEnumTypedefElement

public org.jdom2.Element makeEnumTypedefElement(EnumTypedef etd)

makeExplicitNetcdfElement

public org.jdom2.Element makeExplicitNetcdfElement(NetcdfFile ncFile,
                                                   @Nullable
                                                   java.lang.String location)

makeGroupElement

public org.jdom2.Element makeGroupElement(Group group)

makeNetcdfElement

public org.jdom2.Element makeNetcdfElement(NetcdfFile ncFile,
                                           @Nullable
                                           java.lang.String location)

makeValuesElement

public org.jdom2.Element makeValuesElement(Variable variable,
                                           boolean allowRegular)
                                    throws java.io.IOException

Creates a <values> element from the variable's data.

Parameters:

variable - the variable to read values from

allowRegular - true if regular values should be represented with start, increment, and npts attributes instead of space-separated Element text. Has no effect if the data isn't regular.

Returns:

the <values> element.

Throws:

java.io.IOException - if there was an I/O error when reading the variable's data.

makeVariableElement

public org.jdom2.Element makeVariableElement(Variable var,
                                             boolean showValues)

writeToFile

public void writeToFile(org.jdom2.Element elem,
                        java.io.File outFile)
                 throws java.io.IOException

Writes an NcML element to an output file.

Parameters:

elem - an NcML element.

outFile - the file to write the NcML document to.

Throws:

java.io.IOException - if there's any problem writing.

writeToStream

public void writeToStream(org.jdom2.Element elem,
                          java.io.OutputStream outStream)
                   throws java.io.IOException

Writes an NcML element to an output stream.

Parameters:

elem - an NcML element.

outStream - the stream to write the NcML document to. Will be closed at end of the method.

Throws:

java.io.IOException - if there's any problem writing.

writeToString

public java.lang.String writeToString(org.jdom2.Element elem)

Writes an NcML element to a string.

Parameters:

elem - an NcML element.

Returns:

the string that represents the NcML document.

writeToWriter

public void writeToWriter(org.jdom2.Element elem,
                          java.io.Writer writer)
                   throws java.io.IOException

Writes an NcML element to a Writer.

Parameters:

elem - an NcML element.

writer - the Writer to write the NcML document to. Will be closed at end of the method.

Throws:

java.io.IOException - if there's any problem writing.