How do I create a java.io.File object from URL?

By Wayan in Apache Commons, Commons IO 0 Comment

The code snippet below uses the FileUtils.toFile(URL) method that can be found in the Apache Commons IO library to convert a URL into a File. The url protocol should be file or else null will be returned.

package org.kodejava.commons.io;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.util.Objects;

public class URLToFileObject {
    public static void main(String[] args) throws Exception {
        // FileUtils.toFile(URL url) convert from URL the File.
        String data = FileUtils.readFileToString(Objects.requireNonNull(
                        FileUtils.toFile(URLToFileObject.class.getResource("/data.txt"))),
                StandardCharsets.UTF_8);
        System.out.println("data = " + data);

        // Creates a URL with file protocol and convert it into File object.
        File file = FileUtils.toFile(URI.create("file:///D:/data.txt").toURL());
        data = FileUtils.readFileToString(file, StandardCharsets.UTF_8);
        System.out.println("data = " + data);
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.16.1</version>
</dependency>

Maven Central

How do I parse an XML file using SAX?

By Wayan in XML 0 Comment

This example show you how to read / parse an xml file using the SAX (Simple API for XML) parser. In the main class (SAXDemo) we create the instance of SAXParserFactory and the SAXParser. The SAXParser.parse() method will parse the given InputStream and handle the xml document using the SAXHandler class that we created.

package org.kodejava.xml;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.InputStream;

public class SAXDemo {
    public static void main(String[] args) throws Exception {
        // Creates a new instance of SAXParserFactory that in turn
        // creates a SAXParser.
        SAXParserFactory factory = SAXParserFactory.newInstance();
        SAXParser parser = factory.newSAXParser();

        // The handler that will listen to the SAX event during
        // the xml traversal.
        SAXHandler handler = new SAXHandler();
        InputStream data = SAXDemo.class.getResourceAsStream("/person.xml");
        parser.parse(data, handler);
    }
}

The SAXHandler class extended from the org.xml.sax.helpers.DefaultHandler class. The handler will listen to the event triggered by the SAXParser. This handler methods is defined by the interfaces such as the ContentHandler, ErrorHandler, DTDHandler, and EntityResolver.

For example to read the content of the XML file there are methods to listen to events such as startDocument, endDocument, startElement, endElement, etc, which defined by the ContentHandler interface.

package org.kodejava.xml;

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

public class SAXHandler extends DefaultHandler {
    @Override
    public void startDocument() throws SAXException {
        System.out.println("startDocument");
    }

    @Override
    public void endDocument() throws SAXException {
        System.out.println("endDocument");
    }

    @Override
    public void startElement(String uri, String localName,
                             String qName, Attributes attributes)
            throws SAXException {
        System.out.println("startElement: " + qName);
    }

    @Override
    public void endElement(String uri, String localName,
                           String qName) throws SAXException {
        System.out.println("endElement");
    }

    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {
        System.out.println("characters  : " + new String(ch, start, length));
    }
}

Here an example of the xml file will be read by our program:

<root>
    <persons>
        <person>
            <name>Foo</name>
        </person>
        <person>
            <name>Bar</name>
        </person>
    </persons>
</root>

Our program will print the following output:

startDocument
startElement: root
characters  : 

startElement: persons
characters  : 

startElement: person
characters  : 

startElement: name
characters  : Foo
endElement
characters  : 

endElement
characters  : 

startElement: person
characters  : 

startElement: name
characters  : Bar
endElement
characters  : 

endElement
characters  : 

endElement
characters  : 

endElement
endDocument

How do I create super / subscript in iText?

By Wayan in iText PDF 0 Comment

The following example you’ll see how to create a superscript and subscript text in the pdf document using iText. We can use the Chunk‘s class method called setTextRise(). A positive value will create a superscript text while a negative value will create a subscript text.

package org.kodejava.itextpdf;

import com.itextpdf.text.*;
import com.itextpdf.text.pdf.PdfWriter;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;

public class SuperSubscriptDemo {
    public static void main(String[] args) {
        Document doc = new Document();
        try {
            PdfWriter.getInstance(doc, new FileOutputStream("SuperSubscript.pdf"));
            doc.open();

            Font small = FontFactory.getFont(FontFactory.HELVETICA, 5, Font.ITALIC);

            // Add some chunks into the doc object.
            doc.add(new Chunk("The quick brown  "));

            Chunk superscript = new Chunk("fox ");
            superscript.setTextRise(5f);
            superscript.setFont(small);
            doc.add(superscript);

            doc.add(new Chunk("jumps over the lazy "));

            Chunk subscript = new Chunk("dog");
            subscript.setTextRise(-5f);
            subscript.setFont(small);
            doc.add(subscript);
        } catch (DocumentException | FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            doc.close();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.5.13.3</version>
</dependency>

Maven Central

How do I create an underlined or strike through chunk in iText?

By Wayan in iText PDF 2 Comments

You can use the Chunk‘s setUnderline(float thickness, float yPosition) method to add underline or strike through to a chunk. A negative value to the yPosition create an underline while a positive value will produce a strike through.

package org.kodejava.itextpdf;

import com.itextpdf.text.Chunk;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.PdfWriter;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;

public class UnderlineStrikeThroughDemo {
    public static void main(String[] args) {
        Document doc = new Document();
        try {
            PdfWriter.getInstance(doc, new FileOutputStream("UnderStrike.pdf"));
            doc.open();

            // Creates a chunk with an underline with 0.1 thickness
            Chunk underline = new Chunk("The quick brown fox ");
            underline.setUnderline(0.1f, -1f);
            doc.add(underline);

            // Creates a strike through chunk with 1 thickness
            Chunk strike = new Chunk("jumps over the lazy dog.");
            strike.setUnderline(1f, 3f);
            doc.add(strike);
        } catch (DocumentException | FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            doc.close();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.5.13.3</version>
</dependency>

Maven Central

How do I define a font for text object in iText?

By Wayan in iText PDF 0 Comment

We can set font style for text object such as Chunk, Phrase, Paragraph, etc. using the com.itextpdf.text.Font class. We can define the font face, size, style and its color using this class.

package org.kodejava.itextpdf;

import com.itextpdf.text.*;
import com.itextpdf.text.pdf.PdfWriter;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;

public class FontDemo {
    public static void main(String[] args) {
        Document doc = new Document();
        try {
            PdfWriter.getInstance(doc, new FileOutputStream("FontDemo.pdf"));
            doc.open();

            // Creates some fonts
            Font largeBold = new Font(Font.FontFamily.COURIER, 32,
                    Font.BOLD);
            Font smallItalic = new Font(Font.FontFamily.HELVETICA, 10,
                    Font.ITALIC);
            Font redFont = new Font(Font.FontFamily.TIMES_ROMAN, 12,
                    Font.ITALIC | Font.UNDERLINE, BaseColor.RED);

            // Creates chunk, phrase and paragraph with font
            // information.
            Chunk chunk = new Chunk("Hello World", largeBold);
            Phrase phrase =
                    new Phrase("The quick brown fox ", smallItalic);
            Paragraph paragraph =
                    new Paragraph("jumps over the lazy dog", redFont);

            doc.add(chunk);
            doc.add(phrase);
            doc.add(paragraph);
        } catch (DocumentException | FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            doc.close();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.5.13.3</version>
</dependency>

Maven Central