Package gov.nasa.pds.label

Class Label

  • public class Label
extends java.lang.Object
    Implements a mechanism for accessing labels and the objects they represent.

    For PDS4 labels, the user should load a label file and access the objects as follows: 

     Label label = Label.open(new File("labelfile.xml");

 // Get the tables in the data file.
 List<TableObject> tables = label.getObjects(TableObject.class);

 // Read the table record-by-record.
 TableObject table = tables.get(0);
 TableRecord record = table.readNext();
 while (record != null) {
     ... process this record ...
 }

 label.close();

    See the package gov.nasa.pds.object to see all the object types that can be represented in a PDS label.

    • Method Detail

      • close

        public void close()
        Closes the label. All further calls on the label may generate errors.

      • open

        public static Label open​(java.io.File labelFile)
                  throws ParseException
        Opens a label from a file.
        Parameters:
        labelFile - the label file
        Returns:
        the label
        Throws:
        ParseException - if there is an error reading the label from the file

      • open

        public static Label open​(java.net.URL label)
                  throws ParseException
        Opens a label from a url.
        Parameters:
        label - the label url
        Returns:
        the label
        Throws:
        ParseException - if there is an error reading the label from the url

      • getLabelStandard

        public LabelStandard getLabelStandard()
        Gets the label standard that the label conforms to.
        Returns:
        the label standard

      • getStandardVersion

        public java.lang.String getStandardVersion()
        Returns the version number of the label standard used by the product.
        Returns:
        the label standard version number, as a string

      • getProductClass

        public java.lang.Class<? extends Product> getProductClass()
        Gets the object class of the product.
        Returns:
        the product object class

      • getProductType

        public ProductType getProductType()
        Gets the type of the product, as an enumerated type.
        Returns:
        the product type

      • getObjects

        public java.util.List<DataObject> getObjects()
                                      throws java.lang.Exception
        Gets the data objects represented by the label.
        Returns:
        a list of data objects
        Throws:
        java.lang.Exception - if there is an error accessing the objects in the product

      • getObjects

        public <T extends DataObject> java.util.List<T> getObjects​(java.lang.Class<T> clazz)
                                                    throws java.lang.Exception
        Gets the data objects that are of a given class.
        Type Parameters:
        T - the class of the objects desired
        Parameters:
        clazz - the class object of the object class
        Returns:
        a list of data objects
        Throws:
        java.lang.Exception - if there is an error accessing the objects in the product