Question

Well I am trying to connect to one remote server via socket, and I get big xml responses back from socket, delimited by a ‘\n’ character.

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <data>
       .......
       .......
    </data>
</Response>\n   <---- \n acts as delimiter 
<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <data>
        ....
        ....
    </data>
</Response>\n
..

I am trying to parse these xml using SAX Parser. Ideally I want to get one full response to a string by searching for ‘\n’ and give this response to parser. But since my single response is very large, I am getting outOfMemory Exception when holding such a large xml in string..So the only option remained was to stream the xml to SAX.

SAXParserFactory spfactory = SAXParserFactory.newInstance();
SAXParser saxParser = spfactory.newSAXParser();
XMLReader xmlReader = saxParser.getXMLReader();

xmlReader.setContentHandler(new MyDefaultHandler(context));

InputSource xmlInputSource  =   new InputSource(new    
                    CloseShieldInputStream(mySocket.getInputStream()));
xmlReader.parse(xmlInputSource);

I am using closeShieldInputStream to prevent SAX closing my socket stream on exception because of ‘\n’. I asked a previous question on that..

Now sometimes I am getting Parse Error

org.apache.harmony.xml.ExpatParser$ParseException: At line 1, column 8: not well-formed (invalid token)

I searched for it and found out this error normally comes when the encoding of actual xml is not same as what SAX expecting. I wrote a C program and print out the xml, and all my xml is encoded by UTF-8.

Now my question..

1. Is there any other reason for the above given error in xml parsing
   other than encoding issue
2. Is there any way to print (or write to any file) the input to SAX as
   it streams from socket?

After trying Hemal Pandya’s answer..

OutputStream log = new BufferedOutputStream(new FileOutputStream("log.txt"));
InputSource xmlInputSource  =   new InputSource(new CloseShieldInputStream(new   
                                    TeeInputStream(mReadStream, log)));
xmlReader.parse(xmlInputSource);

a new file with name log.txt getting created when I mount the SDCard but it is empty..Am I using this right?

Well Finally how I done it..

I worked it out with TeeInputStream itself..thanks Hemal Pandya for suggesting that..

//open a log file in append mode..
OutputStream log = new BufferedOutputStream(new FileOutputStream("log.txt",true));
InputSource xmlInputSource  =   new InputSource(new CloseShieldInputStream(new   
                                        TeeInputStream(mReadStream, log)));
try{
  xmlReader.parse(xmlInputSource);
  //flush content in the log stream to file..this code only executes if parsing completed successfully 
  log.flush();
}catch(SaxException e){
  //we want to get the log even if parsing failed..So we are making sure we get the log in either case..
  log.flush();
}

Answer 1

Is there any way to print (or write to any file) the input to SAX as
it streams from socket?

Apache Commons has a TeeInputStream that should be useful.

OutputStream log = new BufferedOutputStream(new FileOutputtStream("response.xml"));
InputSource xmlInputSource  =   new InputSource(new    
                    CloseShieldInputStream(new TeeInputStream(mySocket.getInputStream(), log)));

I haven’t used it, you might want to try it first in a standalone program to figure out close semantics, though looking at docs and your requirements it looks like you would want to close it separately at end.