CODEWITHSUNDEEP
javahtmlswingparsingsax
Sybuser
Sybuser

Reputation: 1374

How do I load an HTML table to a swing JTable?

The HTML table input doesn't have TH for table headers and has TD with bold text instead

It looks like this:

<html>
<body>
<table>
<tr>
<td>
<b>column1</b>
</td>
<td>
<b>column2</b>
</td>
<td>
<b>column3</b>
</td>
</tr><tr>
<td>
value1
</td>
<td>
value2
</td>
<td>
value3
</td>
</tr>
</table>
</html>

So I would like the HTML table headers to processed as JTable columns and the other TDs after the first table row to be processed as JTable cells.

Upvotes: 1

Views: 323

Answers (2)

camickr
camickr

Reputation: 324118

If you want to use standard classes of the JDK you could do something like:

import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.text.*;
import javax.swing.text.html.*;
import javax.swing.text.html.parser.*;

public class ParserCallbackTable extends HTMLEditorKit.ParserCallback
{
    private boolean tableFound = false;

    private Vector<Object> columnNames;
    private Vector<Vector<Object>> data = new Vector<Vector<Object>>();

    private Vector<Object> row;

    public ParserCallbackTable(String uri)
    {
        try
        {
            Reader reader = getReader( uri );
            new ParserDelegator().parse(reader, this, true);
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    public void handleStartTag(HTML.Tag tag, MutableAttributeSet a, int pos)
    {
        if ("table".equals(tag.toString()))
            tableFound = true;

        if ("tr".equals(tag.toString()))
            row = new Vector<Object>();
    }

    public void handleEndTag(HTML.Tag tag, int pos)
    {
        if ("table".equals(tag.toString()))
            tableFound = false;

        if ("tr".equals(tag.toString()))
        {
            if (columnNames == null) // first row of data is the column names
                columnNames = row;
            else
                data.add( row );
        }
    }

    public void handleText(char[] data, int pos)
    {
        if (tableFound)
            row.add( new String(data) );
    }

    public TableModel getModel()
    {
        return new DefaultTableModel(data, columnNames);
    }

    private Reader getReader(String uri) throws IOException
    {
        if (uri.startsWith("http")) // Retrieve from Internet
        {
            URLConnection conn = new URL(uri).openConnection();
            return new InputStreamReader(conn.getInputStream());
        }
        else // Retrieve from file
        {
            return new FileReader(uri);
        }
    }

    public static void main(String[] args) throws IOException
    {
        ParserCallbackTable parser = new ParserCallbackTable( args[0] );
        JTable table = new JTable( parser.getModel() );

        JFrame frame = new JFrame("HTML to JTable");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add( new JScrollPane(table) );
        frame.pack();
        frame.setLocationByPlatform( true );
        frame.setVisible( true );
    }
}

Just pass the name of you HTML file for a quick test. For example:

java ParserCallbackTable table.html

Upvotes: 1

Sybuser
Sybuser

Reputation: 1374

I chose to use this parser as a maven dependency

        <dependency>
            <groupId>org.htmlparser</groupId>
            <artifactId>htmlparser</artifactId>
            <version>2.1</version>
        </dependency>

I invoked the SAX parser like this :

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;

import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class TestHTML {

    public static void main(String[] args) throws IOException, SAXException {
        org.xml.sax.XMLReader reader = org.xml.sax.helpers.XMLReaderFactory.createXMLReader("org.htmlparser.sax.XMLReader");
        HTMLTableContentHandler htmlTableContentHandler = new HTMLTableContentHandler();
        reader.setContentHandler(htmlTableContentHandler);
        String userDir = System.getProperty("user.home");
        byte[] contents = Files.readAllBytes(Paths.get(userDir, "test.html"));
        reader.parse(new InputSource(new ByteArrayInputStream(contents)));
        SwingUtilities.invokeLater(() -> {
            JFrame frame = new JFrame();
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.add(new JScrollPane(new JTable(htmlTableContentHandler.getRowData(), htmlTableContentHandler.getColumnNames())));
            frame.pack();
            frame.setVisible(true);
        });
    }
}

The content handler fills the arrays for the JTable as it goes through the SAX events:

import java.util.ArrayList;
import java.util.List;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class HTMLTableContentHandler extends DefaultHandler {

    private List<Object> columnNames = new ArrayList<>();
    private List<Object[]> rowData = new ArrayList<>();
    private StringBuilder content = new StringBuilder();
    private int rowIndex;
    private int colIndex;
    private boolean readingColumnName;
    private boolean readingCell;

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        if ("B".equals(localName) && rowIndex == 0) {
            if (readingColumnName) {
                columnNames.add(content.toString().trim());
                readingColumnName = false;
            } else {
                readingColumnName = true;
            }
        }
        if ("TD".equals(localName) && rowIndex > 0) {
            readingCell = true;
        }
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        if (readingColumnName || readingCell) {
            content.append(ch, start, length);
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if ("TR".equals(localName)) {
            rowIndex++;
            colIndex = 0;
        }
        if ("TD".equals(localName) && rowIndex > 0) {
            if (colIndex == 0) {
                rowData.add(new Object[columnNames.size()]);
            }
            rowData.get(rowIndex - 1)[colIndex++] = content.toString().trim();
            readingCell = false;
        }
        content.setLength(0);
    }

    public Object[] getColumnNames() {
        return columnNames.toArray();
    }

    public Object[][] getRowData() {
        return rowData.toArray(new Object[0][]);
    }
}

Upvotes: 1

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