使用hadoop将XML转换为CSV

Question

guys i am trying in convert my xml file to csv using hadoop so i am using the following code in mapper class

   protected void map(LongWritable key, Text value,
                 @SuppressWarnings("rawtypes") Mapper.Context context)
  throws
  IOException, InterruptedException {
String document = value.toString();
System.out.println("‘" + document + "‘");
    try {
  XMLStreamReader reader =
      XMLInputFactory.newInstance().createXMLStreamReader(new
          ByteArrayInputStream(document.getBytes()));
  String propertyName = "";
  String propertyValue = "";
  String currentElement = "";
  while (reader.hasNext()) {
    int code = reader.next();
    switch (code) {
      case XMLStreamConstants.START_ELEMENT: //START_ELEMENT:
        currentElement = reader.getLocalName();
        break;
      case XMLStreamConstants.CHARACTERS:  //CHARACTERS:
        if (currentElement.equalsIgnoreCase("author")) {
          propertyName += reader.getText();
         } else if (currentElement.equalsIgnoreCase("price"))
        {
            String name=reader.getText();
            name.trim();
          propertyName += name;
          propertyName.trim();
         }
 }
        console.write(null,new Text(propertyName));
 }
 }

but the output i am getting is in this form

Gambardella, Matthew
      XML Developer's Guide
      44.95
      2000-10-01


Ralls, Kim
      Midnight Rain
      5.95
      2000-12-16

can u help me with this

Answer 1

The output of the program depends on how you are collecting/writing from mapper.

In this case you should be using TextOutputFormat & KeyOut will be NullWritable and ValueOut will be Text. The Value out should be a concatenation of the values which you extracted from CSV.

From your code it looks like you are writing output after reading each value from the XML.