Question

I’m working on a project and have encountered a problem. I am trying to parse html using html cleaner and then use xpath to return a string. I made it return a stacktrace if it found an error (Which it did). I really have no idea how to go about debugging it based on the stack trace. Here’s the code.

package ru.habrahabr.stackparser;

import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.htmlcleaner.TagNode;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.*;

public class stackParser extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button button = (Button) findViewById(R.id.parse);
    button.setOnClickListener(myListener);
}


private ProgressDialog pd;

private OnClickListener myListener = new OnClickListener() {
    public void onClick(View v) {
        pd = ProgressDialog.show(stackParser.this, "Working...",
                "request to server", true, false);
        new parseSite()
                .execute("http://wiki.teamliquid.net/starcraft2/3_Gate_Robo");
    }
};

private class parseSite extends AsyncTask<String, Void, String> {
    protected String doInBackground(String... arg) {
        String output = new String();
        try {
            htmlHelper hh = new htmlHelper(new URL(arg[0]));
            output = hh.htmlHelper(arg[0]);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return output;
    }


    protected void onPostExecute(String output) {
        pd.dismiss();
        TextView view = (TextView) findViewById(R.id.tv1);
        view.setText(output);

    }
}

Here’s my HTML helper class

package ru.habrahabr.stackparser;

import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.htmlcleaner.CleanerProperties;
import org.htmlcleaner.HtmlCleaner;
import org.htmlcleaner.TagNode;
import org.htmlcleaner.XPatherException;

public class htmlHelper {
TagNode rootNode;

public htmlHelper(URL url) {
    // TODO Auto-generated constructor stub
}

public String htmlHelper(String arg) throws IOException, XPatherException
{
    CleanerProperties props = new CleanerProperties();

    // set some properties to non-default values
    props.setTranslateSpecialEntities(true);
    props.setTransResCharsToNCR(true);
    props.setOmitComments(true);

    HtmlCleaner cleaner = new HtmlCleaner(props);
    rootNode = cleaner.clean(arg);

    Object[] nodes = rootNode.evaluateXPath("//h1[@id='firstHeading']");

    String things = nodes.toString();

    return things;
}

The UI and loading bar work fine but the TextView keeps returning [Ljava.lang.Object;@42455a88

I’d really appreciate some help with this…i’ve wrestled with it all day and can’t seem to figure it out. Thanks!

Answer 1

I figured it out. The Xpath query was referring to the DOM tree in the XML document. So, in order to avoid a throws, the DOM tree needs to be initialized after cleaning. Then the Xpath will work.