Package io.permazen.util

Class AbstractXMLStreaming

java.lang.Object
io.permazen.util.AbstractXMLStreaming
Direct Known Subclasses:
SchemaItem, SchemaModel, XMLObjectSerializer, XMLSerializer
public abstract class AbstractXMLStreaming extends Object
Support superclass for classes that serialize and deserialize via XML.

  • Constructor Details

    • AbstractXMLStreaming

      protected AbstractXMLStreaming()

  • Method Details

    • expect

      protected boolean expect(XMLStreamReader reader, boolean closingOK, QName... names) throws XMLStreamException
      Scan forward until we see an opening or closing tag. If opening tag is seen, it must match one of names and then we return true, if not or if names is empty throw an exception; if a closing tag is seen, return false if closingOK, else throw exception.
      Parameters:
      reader - XML input
      closingOK - true if a closing tag is OK, otherwise false
      names - expected opening tag, or null if we expected a closing tag
      Returns:
      true if matching opening tag seen, false otherwise
      Throws:
      XMLStreamException - if something unexpected is encountered

    • next

      protected QName next(XMLStreamReader reader) throws XMLStreamException
      Skip forward until either the next opening tag is reached, or the currently open tag is closed.
      Parameters:
      reader - XML input
      Returns:
      the XML opening tag found, or null if a closing tag was seen first
      Throws:
      XMLStreamException - if no opening tag is found before the current tag closes
      XMLStreamException - if something unexpected is encountered

    • skip

      protected void skip(XMLStreamReader reader) throws XMLStreamException
      Skip over the remainder of the current XML element, including any nested elements, until the closing XML tag is seen and consumed.
      Parameters:
      reader - XML input
      Throws:
      XMLStreamException - if something unexpected is encountered

    • expectClose

      protected void expectClose(XMLStreamReader reader) throws XMLStreamException
      Scan forward expecting to see a closing tag.

      Equivalant to: expect(reader, true).

      Parameters:
      reader - XML input
      Throws:
      XMLStreamException - if something other than a closing tag is encountered

    • writeElement

      protected void writeElement(XMLStreamWriter writer, QName element, String content) throws XMLStreamException
      Write out a simple XML element containing the given content.
      Parameters:
      writer - XML output
      element - element name
      content - simple content
      Throws:
      XMLStreamException - if error occurs writing output

    • writeEmptyElement

      protected void writeEmptyElement(XMLStreamWriter writer, QName name) throws XMLStreamException
      Start an empty XML element.
      Parameters:
      writer - XML output
      name - element name
      Throws:
      XMLStreamException - if error occurs writing output

    • writeStartElement

      protected void writeStartElement(XMLStreamWriter writer, QName name) throws XMLStreamException
      Start a non-empty XML element.
      Parameters:
      writer - XML output
      name - element name
      Throws:
      XMLStreamException - if error occurs writing output

    • writeAttr

      protected void writeAttr(XMLStreamWriter writer, QName name, Object value) throws XMLStreamException
      Write out an attribute.
      Parameters:
      writer - XML output
      name - attribute qualified name
      value - attribute value
      Throws:
      XMLStreamException - if error occurs writing output

    • getAttr

      protected String getAttr(XMLStreamReader reader, QName name, boolean required) throws XMLStreamException
      Get an attribute from the current element.
      Parameters:
      reader - XML input
      name - attribute name
      required - whether attribute must be present
      Returns:
      attribute value, or null if not required and no attribute is present
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if required is true and no such attribute is found

    • getAttr

      protected String getAttr(XMLStreamReader reader, QName name) throws XMLStreamException
      Get a requried attribute from the current element. Equivalent to: getAttr(reader, name, true).
      Parameters:
      reader - XML input
      name - attribute name
      Returns:
      attribute value
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if no such attribute is found

    • getIntAttr

      protected Integer getIntAttr(XMLStreamReader reader, QName name, boolean required) throws XMLStreamException
      Get an attribute from the current element and parse as a decimal integer value.
      Parameters:
      reader - XML input
      name - attribute name
      required - whether attribute must be present
      Returns:
      attribute value, or null if not required and no attribute is present
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if required is true and no such attribute is found
      XMLStreamException - if attribute is not an integer value

    • getLongAttr

      protected Long getLongAttr(XMLStreamReader reader, QName name, boolean required) throws XMLStreamException
      Get an attribute from the current element and parse as a decimal long value.
      Parameters:
      reader - XML input
      name - attribute name
      required - whether attribute must be present
      Returns:
      attribute value, or null if not required and no attribute is present
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if required is true and no such attribute is found
      XMLStreamException - if attribute is not an integer value

    • getIntAttr

      protected int getIntAttr(XMLStreamReader reader, QName name) throws XMLStreamException
      Get a requried integer attribute from the current element. Equivalent to: getIntAttr(reader, name, true).
      Parameters:
      reader - XML input
      name - attribute name
      Returns:
      attribute value
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if no such attribute is found
      XMLStreamException - if attribute is not an integer value

    • getBooleanAttr

      protected Boolean getBooleanAttr(XMLStreamReader reader, QName name, boolean required) throws XMLStreamException
      Get an attribute from the current element and parse as a boolean value.
      Parameters:
      reader - XML input
      name - attribute name
      required - whether attribute must be present
      Returns:
      attribute value, or null if not required and no attribute is present
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if required is true and no such attribute is found
      XMLStreamException - if attribute is not "true" or "false"

    • getBooleanAttr

      protected boolean getBooleanAttr(XMLStreamReader reader, QName name) throws XMLStreamException
      Get a requried boolean attribute from the current element. Equivalent to: getBooleanAttr(reader, name, true).
      Parameters:
      reader - XML input
      name - attribute name
      Returns:
      attribute value
      Throws:
      IllegalStateException - if the current event is not a start element event
      XMLStreamException - if no such attribute is found
      XMLStreamException - if attribute is not "true" or "false"

    • newInvalidAttributeException

      protected XMLStreamException newInvalidAttributeException(XMLStreamReader reader, QName name, String description, Throwable... cause) throws XMLStreamException
      Build a XMLStreamException caused by invalid content in an attribute.
      Parameters:
      reader - XML input
      name - attribute name
      description - a description of the problem
      cause - optional underlying exception for chaining
      Returns:
      exception to throw
      Throws:
      IllegalArgumentException - if more than one cause is given
      XMLStreamException - if error occurs accessing the attribute value

    • newInvalidInputException

      protected XMLStreamException newInvalidInputException(XMLStreamReader reader, String format, Object... args)
      Build a XMLStreamException caused by invalid input.
      Parameters:
      reader - XML input
      format - format string for String.format()
      args - format arguments for String.format()
      Returns:
      exception to throw

    • newInvalidInputException

      protected XMLStreamException newInvalidInputException(XMLStreamReader reader, Throwable cause, String format, Object... args)
      Build a XMLStreamException caused by invalid input.

      This method exists to help workaround JDK-8322027.

      Parameters:
      reader - XML input
      cause - optional underlying exception for chaining, or null for none
      format - format string for String.format()
      args - format arguments for String.format()
      Returns:
      exception to throw