Question: how can we convert html to well formed xhtml by using Http class api,if possible please give a
demonstration code....thanks

Answer: 
Have a look at J-Tidy: <http://jtidy.sourceforge.net/> It usually does a quite good job cleaning up messy html and converting it to xhtml.
You can use the following method to get xhtml from html

```
public static String getXHTMLFromHTML(String inputFile,
            String outputFile) throws Exception {

        File file = new File(inputFile);
        FileOutputStream fos = null;
        InputStream is = null;
        try {
            fos = new FileOutputStream(outputFile);
            is = new FileInputStream(file);
            Tidy tidy = new Tidy(); 
            tidy.setXHTML(true); 
            tidy.parse(is, fos);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }finally{
            if(fos != null){
                try {
                    fos.close();
                } catch (IOException e) {
                    fos = null;
                }
                fos = null;
            }
            if(is != null){
                try {
                    is.close();
                } catch (IOException e) {
                    is = null;
                }
                is = null;
            }
        }

        return outputFile;
    }

```