Package org.orekit.files.sp3

Class NsgfV00Filter

java.lang.Object

org.orekit.files.sp3.NsgfV00Filter

All Implemented Interfaces:

DataFilter

public class NsgfV00Filter
extends Object
implements DataFilter

Filter for some non-official files from CDDIS.

Some files produced by UKRI/NERC/British Geological Survey Space Geodesy Facility (SGF) claim to be SP3c but are really SP3d since they have more than 4 comments lines. This filter can be used to parse them.

Since:

12.1

See Also:

SP3 precise orbit file is not compliant with SP3 format c (extra comment line)

Field Summary

Fields

Modifier and Type	Field	Description
static String	DEFAULT_V00_PATTERN	Default regular expression for NSGF V00 files.

Constructor Summary

Constructors

Constructor	Description
NsgfV00Filter()	Simple constructor.
NsgfV00Filter(String nameRegexp, Function<String,String> renaming)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
DataSource	filter(DataSource original)	Filter the data source.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_V00_PATTERN

public static final String DEFAULT_V00_PATTERN

Default regular expression for NSGF V00 files.

See Also:

Constant Field Values

Constructor Detail

NsgfV00Filter

public NsgfV00Filter(String nameRegexp,
                     Function<String,String> renaming)

Simple constructor.

Parameters:

nameRegexp - regular expression matching file names to which filtering should be applied

renaming - function to apply for renaming files (and avoid the filter to be applied in infinite recursion)

NsgfV00Filter

public NsgfV00Filter()

Simple constructor.

This uses DEFAULT_V00_PATTERN as the regular expression matching files that must be filtered, and replaces "v00" by "v70" to generate the filtered name.

Method Detail

filter

public DataSource filter(DataSource original)
                  throws IOException

Filter the data source.

Filtering is often based on suffix. For example a gzip compressed file will have an original name of the form base.ext.gz when the corresponding uncompressed file will have a filtered name base.ext.

A filter must never open the DataSource by itself, regardless of the fact it will return the original instance or a filtered instance. The rationale is that it is the upper layer that will decide to open (or not) the returned value and that a DataSource can be opened only once; this is the core principle of lazy-opening provided by DataSource.

Beware that as the data providers manager will attempt to pile all filters in a stack as long as their implementation of this method returns a value different from the original parameter. This implies that the filter, must perform some checks to see if it must be applied or not. If for example there is a need for a deciphering filter to be applied once to all data, then the filter should for example check for a suffix in the name and create a new filtered DataSource instance only if the suffix is present, removing the suffix from the filtered instance. Failing to do so and simply creating a filtered instance with one deciphering layer without changing the name would result in an infinite stack of deciphering filters being built, until a stack overflow or memory exhaustion exception occurs.

Specified by:

filter in interface DataFilter

Parameters:

original - original data source

Returns:

filtered data source, or original if this filter does not apply to this data source

Throws:

IOException - if filtered stream cannot be created