Other Libraries - Learn Java by Examples

How do I create DateTime object in Joda-Time?

By I Wayan Saryada in Joda-Time Last modified: June 2, 2023 0 Comment

The following example show you a various way to create an instance of Joda-Time’s DateTime class. By using the default constructor we will create an object with the current system date time. We can also create the object by passing the information like year, month, day, hour, minutes and second.

Joda can also use an instance from JDK’s java.util.Date and java.util.Calendar to create the DateTime. This means that the date object of JDK and Joda can be used to work together in our application.

package org.kodejava.joda;

import org.joda.time.DateTime;
import org.joda.time.format.DateTimeFormat;

import java.util.Calendar;
import java.util.Date;

public class DateTimeDemo {

    public static void main(String[] args) {
        // Creates DateTime object using the default constructor will
        // give you the current system date.
        DateTime date = new DateTime();
        System.out.println("date = " + date);

        // Or simply calling the now() method.
        date = DateTime.now();
        System.out.println("date = " + date);

        // Creates DateTime object with information like year, month,
        // day, hour, minute, second and milliseconds
        date = new DateTime(2021, 10, 29, 0, 0, 0, 0);
        System.out.println("date = " + date);

        // Create DateTime object from milliseconds.
        date = new DateTime(System.currentTimeMillis());
        System.out.println("date = " + date);

        // Create DateTime object from Date object.
        date = new DateTime(new Date());
        System.out.println("date = " + date);

        // Create DateTime object from Calendar object.
        Calendar calendar = Calendar.getInstance();
        date = new DateTime(calendar);
        System.out.println("date = " + date);

        // Create DateTime object from string. The format of the
        // string  should be precise.
        date = new DateTime("2021-10-29T06:30:00.000+08:00");
        System.out.println("date = " + date);
        date = DateTime.parse("2021-10-29");
        System.out.println("date = " + date);
        date = DateTime.parse("29/10/2021",
                DateTimeFormat.forPattern("dd/MM/yyyy"));
        System.out.println("date = " + date);
    }
}

The result of our code snippet:

date = 2021-10-29T06:30:01.068+08:00
date = 2021-10-29T06:30:01.147+08:00
date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T06:30:01.148+08:00
date = 2021-10-29T06:30:01.148+08:00
date = 2021-10-29T06:30:01.166+08:00
date = 2021-10-29T06:30:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00

Maven Dependencies

<dependency>
    <groupId>joda-time</groupId>
    <artifactId>joda-time</artifactId>
    <version>2.12.5</version>
</dependency>

How do I use Joda-Time’s DateMidnight class?

By I Wayan Saryada in Joda-Time Last modified: June 2, 2023 0 Comment

The org.joda.time.DateMidnight class represent a date time information with the time value set to midnight. The following snippet show you how to instantiate this class.

package org.kodejava.joda;

import org.joda.time.DateMidnight;
import org.joda.time.format.DateTimeFormat;

public class DateMidnightDemo {
    public static void main(String[] args) {
        // Create DateMidnight object of the current system date.
        DateMidnight date = new DateMidnight();
        System.out.println("date = " + date);

        // Or using the now().
        date = DateMidnight.now();
        System.out.println("date = " + date);

        // Create DateMidnight object by year, month and day.
        date = new DateMidnight(2021, 10, 29);
        System.out.println("date = " + date);

        // Create DateMidnight object from milliseconds.
        date = new DateMidnight(System.currentTimeMillis());
        System.out.println("date = " + date);

        // Parse a date from string.
        date = DateMidnight.parse("2021-10-29");
        System.out.println("date = " + date);

        // Parse a date from string of specified patter.
        date = DateMidnight.parse("29/10/2021", 
                DateTimeFormat.forPattern("dd/MM/yyyy"));
        System.out.println("date = " + date);
    }
}

The result of our code snippet:

date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00
date = 2021-10-29T00:00:00.000+08:00

Maven Dependencies

<dependency>
    <groupId>joda-time</groupId>
    <artifactId>joda-time</artifactId>
    <version>2.12.5</version>
</dependency>

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

By I Wayan Saryada in Apache Commons, Commons IO Last modified: June 4, 2024 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>

How do I create super / subscript in iText?

By I Wayan Saryada in iText PDF Last modified: June 2, 2023 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>

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

By I Wayan Saryada in iText PDF Last modified: June 2, 2023 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>