// Create an EDIInputFactory
EDIInputFactory factory = EDIInputFactory.newFactory();

// Obtain an InputStream of the EDI document to read.
InputStream stream = new FileInputStream(...);

// Create an EDIStreamReader from the stream using the factory
EDIStreamReader reader = factory.createEDIStreamReader(stream);

// First event - EDIStreamEvent.START_INTERCHANGE
EDIStreamEvent event = reader.next();

// Second event - EDIStreamEvent.START_SEGMENT
event = reader.next();

// Object the event text (segment tag for EDIStreamEvent.START_SEGMENT)
String segmentName = reader.getText();

// Continue processing the stream...

EDIInputFactory factory = EDIInputFactory.newFactory();

// Obtain Stream to the EDI document to read.
InputStream stream = new FileInputStream(...);

EDIStreamReader reader = factory.createEDIStreamReader(stream);

while (reader.hasNext()) {
  switch (reader.next()) {
  case START_INTERCHANGE:
    /* Retrieve the standard - "X12", "EDIFACT", or "TRADACOMS" */
    String standard = reader.getStandard();

    /*
     * Retrieve the version string array. An array is used to support
     * the componentized version element used in the EDIFACT standard.
     *
     * e.g. [ "00501" ] (X12) or [ "UNOA", "3" ] (EDIFACT)
     */
    String[] version = reader.getVersion();
    break;

  case START_SEGMENT:
    // Retrieve the segment name - e.g. "ISA" (X12), "UNB" (EDIFACT), or "STX" (TRADACOMS)
    String segmentName = reader.getText();
    break;

  case END_SEGMENT:
    break;

  case START_COMPOSITE:
    break;

  case END_COMPOSITE:
    break;

  case ELEMENT_DATA:
    // Retrieve the value of the current element
    String data = reader.getText();
    break;
  }
}

reader.close();
stream.close();

// Create an EDIInputFactory
EDIInputFactory factory = EDIInputFactory.newFactory();
factory.setProperty(EDIInputFactory.EDI_VALIDATE_CONTROL_CODE_VALUES, false);

// Obtain an InputStream of the EDI document to read.
InputStream stream = new FileInputStream(...);

// Create an EDIStreamReader from the stream using the factory
EDIStreamReader reader = factory.createEDIStreamReader(stream);

// Continue processing with the reader...

EDIOutputFactory factory = EDIOutputFactory.newFactory();

// Obtain Stream write the EDI document.
OutputStream stream = new FileOutputStream(...);

EDIStreamWriter writer = factory.createEDIStreamWriter(stream);
int groupCount = 0;

writer.startInterchange();

// Write interchange header segment
writer.writeStartSegment("ISA")
      .writeElement("00")
      .writeElement("          ")
      .writeElement("00")
      .writeElement("          ")
      .writeElement("ZZ")
      .writeElement("ReceiverID     ")
      .writeElement("ZZ")
      .writeElement("Sender         ")
      .writeElement("203001")
      .writeElement("1430")
      .writeElement("^")
      .writeElement("00501")
      .writeElement("000000001")
      .writeElement("0")
      .writeElement("P")
      .writeElement(":")
      .writeEndSegment();

// Write functional group header segment
groupCount++;
writer.writeStartSegment("GS");
writer.writeStartElement();

// Continue writing remainder of functional group

writer.writeStartSegment("IEA")
      .writeElement(String.valueOf(groupCount))
      .writeElement("000000001")
      .writeEndSegment();

writer.endInterchange();

writer.close();
stream.close();