Java Enum Generator - from CSV files

Generates java Enums from CSV files

Goals

• enables seamless generation of Java enums for large datasets

Formating the CSV file

• the CSV file must be properly formatted in order for the generator to run properly
• the first line of the CSV consists of all the variable types/names
• one of the header cells must contain the word VALUE which indicates the column is reserved for the enum constant names
• example header: VALUE,String country,String code

Running from the Command Line

• The jar file is located in out/artificats/CsvEnumGenerator_jar
• Argument Ordering:
  1. CSV file to read from
  2. Name of the enum
  3. output file
• Running the generator from the command line: java -jar CsvEnumGenerator.jar csvFile.csv ENUMNAME enumname.java
• if using Intellij use Ctrl+Alt+L to reformat the enum source code

Sample parseable CSV

VALUE,String countryName,String alpha2,String alpha3
CANADA,Canada,CA,CAN
UNITED_STATES,United States,US,USA

• aside from the reserved VALUE cell header, all other headers must contain a space to separate the variable type and variable name

Generating with custom data types

• whenever a custom data type is used simply create an additional constructor after the enum is generated that parses the String and converts it to the specified object type

Custom data type example

VALUE,String countryName,LocalDate foundedOn
CANADA,Canada,1867-07-01
UNITED_STATES,United States of America,1776-07-04

Generated Enum: java -jar CsvEnumGenerator.jar countries.csv COUNTRY countries.java

public enum COUNTRY { 

  CANADA("Canada","1867-07-01"),
  UNITED_STATES("United States Of America","1776-07-04");

  private final String countryName;
  private final LocalDate foundedOn;


  COUNTRY(String countryName,LocalDate foundedOn) {
    this.countryName = countryName;
    this.foundedOn = foundedOn;
  }
  
  public String getCountryName() {
    return this.countryName;
  }

  public LocalDate getFoundedOn() {
    return this.foundedOn;
  }
}

Code to add:

 private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
 
 COUNTRY(String countryName, String foundedOn) {
  LocalDate date = LocalDate.parse(foundedOn, formatter);
  this(countryName, date);
 }

• As you can see for large data sets the csv-enum generator will signficantly reduce the manual work/number of lines a developer has to write

Technologies Used

• Java 8
• Maven
• Guava
• Lombok
• Apache Commons Lang
• Apache Commons CSV

Please feel free to reach out if there are any improvements that can be made or if you have any questions :)