Quirk CSV

A thread-safe library that allows you to parse and write csv files using java annotations quickly and efficiently!

Table of Contents

1. Maven Dependency
2. Demos
3. Quick Start
4. Reading(Parsing) CSV
5. Writing(Generating) CSV
6. Wrappers for handling Non-primitive types
7. Inheritance
8. Extending Apache commons-csv

Maven Dependency

<dependency>
  <groupId>io.github.bpoole6</groupId>
  <artifactId>quirk-csv</artifactId>
  <version>1.0.0</version>
</dependency>

DEMOS

ORDER | NAMED | INHERITANCE | WRAPPER | LARGE DATA PROCESSING

Quick Start

POJO

@CSVReadComponent(type = CSVType.NAMED)
@CSVWriteComponent(type = CSVType.ORDER)
public class Pojo {
	@CSVWriteBinding(order = 0)
	private String name;

	@CSVWriteBinding(order = 1)
	@CSVReadBinding(header = "age")
	private Integer age;

	@CSVWriteBinding(order = 2)
	@CSVReadBinding(header = "money")
	private Double money;

	@CSVReadBinding(header = "name")
	public void setA(String name) {
		this.name = name;
	}

	@Override
	public String toString() {

		return "Name: " + name + System.lineSeparator() + "\tAge: " + age + System.lineSeparator() + "\tMoney: "
				+ money;
	}

}

Main

import com.quirk.csv.processor.CSVProcessor;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.*;


public class SimpleMain {
    public static void main(String[] args) {
        String csv = "name,age,money" + System.lineSeparator() + "Michael Williams,34,39332.15";

        CSVProcessor processor = new CSVProcessor(Pojo.class);
        List<Pojo> list = new ArrayList<>();
        try {
            list.addAll(processor.parse(new StringReader(csv)));
			list.forEach(System.out::println);

            System.out.println();

            StringWriter sw = new StringWriter();
            processor.write(list, sw);
			System.out.println(sw.toString());
        } catch (IOException e) {
        }


    }
}

Reading CSV

There are two annotations you'll use when parsing a csv @CSVReadComponent and @CSVReadBinding. A CSV is either header based or order based.

If you are parsing a header based then you would set the CSVType to NAMED and @CSVReadBinding will need the header field set to the header it'll get its value from.

Example

import com.quirk.csv.annotation.*;

@CSVReadComponent(type = CSVType.NAMED)
public class Pojo {
	private String name;

	@CSVReadBinding(header = "age")
	private Integer age;

	@CSVReadBinding(header = "money")
	private Double money;

	@CSVReadBinding(header = "name")
	public void setA(String name) {
		this.name = name;
	}

	@Override
	public String toString() {

		return "Name: " + name + System.lineSeparator() + "\tAge: " + age + System.lineSeparator() + "\tMoney: "
				+ money;
	}

    public static void main(String[] args) {
		final String csv = "Marvin Nowell,34,20000.32" + System.lineSeparator() + "Dillian Lamour,22,2499";
		CSVProcessor<Pojo> processor = new CSVProcessor<>(Pojo.class);

		try {
			//Reading
			List<Pojo> list = processor.parse(new StringReader(csv));
			list.forEach(System.out::println);

		} catch (IOException e) {
		}

	}
}

Writing CSV

There are two annotations you'll use when writing a csv @CSVWriteComponent and CSVWriteBinding

Example

Write an ORDER based csv file. Meaning the CSV will not have headers when generated.

import com.quirk.csv.annotation.*;
import com.quirk.csv.processor.CSVProcessor;

import java.io.IOException;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.List;

@CSVWriteComponent(type = CSVType.ORDER)
public class Pojo {

	public Pojo(String name, Integer age, Double money) {
		this.name = name;
		this.age = age;
		this.money = money;
	}

	private String name;

	@CSVWriteBinding(order = 2)
	private Integer age;

	@CSVWriteBinding(order = 1)
	private Double money;


	@CSVWriteBinding(order = 3)
	public String getName() {
		return name;
	}
	
	public static void main(String[] args) {
		CSVProcessor<Pojo> processor = new CSVProcessor<>(Pojo.class);
		try {

			List<Pojo> list = Arrays.asList(new Pojo("Dillian Lamour",22,340.70));
			//Writing
			StringWriter sw = new StringWriter();
			processor.write(list,sw);
			System.out.println(sw.toString());
		} catch (IOException e) {
		}

	}
}

Wrappers Handling Non-primitive types

To handle parsing and reading non-primitive types, use ReadWrapper when parsering a csv and WriteWrapper when writing.

Example

import com.quirk.csv.annotation.*;
import com.quirk.csv.processor.CSVProcessor;
import com.quirk.csv.wrappers.read.ReadWrapper;
import com.quirk.csv.wrappers.write.WriteWrapper;
import org.apache.commons.csv.CSVFormat;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@CSVReadComponent(type = CSVType.ORDER)
@CSVWriteComponent(type = CSVType.NAMED, namedIsOrdered = true)
public class Pojo {

    @CSVReadBinding(order = 1, wrapper = LocalDateReadWrapper.class) //Specifying
    private LocalDate dob;

    @CSVWriteBinding(order = 0, header = "id")
    public LocalDate getDob() {
        return dob;
    }

    @Override
    public String toString() {
        return "Date Of Birth: " + dob + System.lineSeparator();
    }

    public static class LocalDateReadWrapper implements ReadWrapper<LocalDate> {

        @Override
        public LocalDate apply(String str) {
            DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyyMMdd");
            try {
                return LocalDate.parse(str, df);
            } catch (Exception e) {
                throw new IllegalArgumentException(e);
            }
        }
    }

    public static class LocalDateWriteWrapper implements WriteWrapper<LocalDate> {
        @Override
        public String apply(LocalDate ld) {
            DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyyMMdd");
            return df.format(ld);
        }
    }

    public static void main(String[] args) {
        final String csv = "Marvin Nowell,19820511,234" + System.lineSeparator() + "Dillian Lamour,19960111,21";
        Map<Class, WriteWrapper> m = new HashMap<>();
        m.put(LocalDate.class, new LocalDateWriteWrapper());
        CSVProcessor<Pojo> processor = new CSVProcessor<>(Pojo.class, new HashMap<>(),m);
        try {

            List<Pojo> list = processor.parse(new StringReader(csv), CSVFormat.DEFAULT);
            list.forEach(System.out::println);

            System.out.println();

            StringWriter sw = new StringWriter();
            processor.write(list,sw);

        } catch (IOException e) {
        }

    }
}

Inheritance

This is used when trying to utilize a parent class' annotations.

Example

import com.quirk.csv.annotation.*;
import com.quirk.csv.processor.CSVProcessor;
import org.apache.commons.csv.CSVFormat;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.List;

@CSVReadComponent(type = CSVType.ORDER)
@CSVWriteComponent(type = CSVType.NAMED)
public class PojoParent {
	@CSVWriteBinding(header = "name")
	private String name;

	@CSVReadBinding(order = 0)
	public void setName(String name) {
		this.name = name;
	}

	@Override
	public String toString() {

		return "Name: " + name;
	}

	// Make sure inheritSuper is TRUE
	@CSVReadComponent(type = CSVType.ORDER, inheritSuper = true)
	@CSVWriteComponent(type = CSVType.NAMED, inheritSuper = true)
	public static class PojoChild extends PojoParent {
		@CSVReadBinding(order = 1)
		@CSVWriteBinding(header = "nationality")
		private String nationality;

		@Override
		public String toString() {

			return super.toString() + System.lineSeparator() + "\tNationality: " + nationality;
		}
	}

	public static void main(String[] args) throws NoSuchMethodException, IOException {
		final String csv = "Marvin Nowell|USA" + System.lineSeparator() + "Dillian Lamour|France";
		CSVProcessor<PojoChild> processor = new CSVProcessor(PojoChild.class);
		try {
			//Reading
			CSVFormat format = CSVFormat.DEFAULT.withDelimiter('|');
			List<PojoChild> list = processor.parse(new StringReader(csv),format);
			list.forEach(System.out::println);

			System.out.println();

			//Writing
			StringWriter sw = new StringWriter();
			processor.write(list,sw);
			System.out.println(sw.toString());
		} catch (IOException e) {
		}


	}
}

CSVFormat

Extending commons-csv

This project is built on top of org.apache.commons:commons-csv and the parser allows you to pass in as an argument CSVFormat. This allows you to specify things such as if your csv file has a header, the delimiter exists as a possible value, and/or etc. For example if you had a csv that was pipe "|" delimited you'd modified the CSVFormat to include it.

CSVFormat format = CSVFormat.DEFAULT.withDelimiter('|');
List<PojoChild> list = processor.parse(new StringReader(csv),format);

Author

Austin Poole Java Developer