How do I call DaisyDiff to compare two HTML files?

I need to create a diff between two HTML documents in my app. I found a library called DaisyDiff that can do it. It has an API that looks like this:

/**
 * Diffs two html files, outputting the result to the specified consumer.
 */
public static void diffHTML(InputSource oldSource, InputSource newSource,
                            ContentHandler consumer, String prefix, Locale locale)
        throws SAXException, IOException

I know absolutely nothing about SAX and I can't figure out what to pass as the third argument. After poking through https://code.google.com/p/daisydiff/source/browse/trunk/daisydiff/src/java/org/outerj/daisy/diff/Main.java I wrote this method:

@Override
    protected String doInBackground(String... params)
    {
        try {
            String oldFileName = params[0],
                    newFileName = params[1];
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            FileInputStream oldis = null, newis = null;
            oldis = openFileInput(oldFileName);
            newis = openFileInput(newFileName);

            SAXTransformerFactory tf = (SAXTransformerFactory) TransformerFactory
                    .newInstance();

            TransformerHandler result = tf.newTransformerHandler();
            result.setResult(new StreamResult(os));
            DaisyDiff.diffHTML(new InputSource(oldis), new InputSource(newis), result, "", Locale.getDefault());

            Log.d("diff", "output length = " + os.size());
            return os.toString("Utf-8");

        }catch (Exception e){
            return e.toString();
        }
    }

I have no idea if that even makes sense. It doesn't work, nothing is written to the output. Please help me with this. Thanks in advance.

According to how HtmlTestFixture.diff is coded up (inside src/test/java of DaisyDiff, you need to give it instructions on how the result should be formatted. Have you tried adding the below setOutputProperty(...) calls?

@Test 
//@Test comes from TestNG and is not related to DaisyDiff
public void daisyDiffTest() throws Exception {
    String html1 = "<html><body>var v2</body></html>";
    String html2 = "<html>  \n  <body>  \n  Hello world  \n  </body>  \n  </html>";

    try {
        StringWriter finalResult = new StringWriter();
        SAXTransformerFactory tf = (SAXTransformerFactory) SAXTransformerFactory.newInstance(); 
        TransformerHandler result = tf.newTransformerHandler(); 
        result.getTransformer().setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); 
        result.getTransformer().setOutputProperty(OutputKeys.INDENT, "yes"); 
        result.getTransformer().setOutputProperty(OutputKeys.METHOD, "html"); 
        result.getTransformer().setOutputProperty(OutputKeys.ENCODING, "UTF-8"); 
        result.setResult(new StreamResult(finalResult)); 

        ContentHandler postProcess = result; 
        DaisyDiff.diffHTML(new InputSource(new StringReader(html1)), new InputSource(new StringReader(html2)), postProcess, "test", Locale.ENGLISH);
        System.out.println(finalResult.toString());
    } catch (SAXException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

Done this way, my output is as follows. Now I can stick this into an HTML file, include the right css and js files and have a pretty output.

var v2 Hello world 

来源：https://stackoverflow.com/questions/30508000/how-do-i-call-daisydiff-to-compare-two-html-files

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sax