GitHub - evanrupert/ExcelKt: Kotlin Wrapper over the Apache POI Excel Library that enables creating xlsx files with kotlin builders

An idiomatic Kotlin wrapper over the Apache POI Excel library for easily generating Excel xlsx files.

Key Features

Write idiomatic kotlin that looks clean and logical
Simple style system that allows you to use the Apache POI CellStyle system to stylize workbooks, sheets, rows, or specific cells
Very lightweight

Installation

Gradle

In your gradle build file add the following:

Kotlin DSL

repositories {
    mavenCentral()
}

dependencies {
    implementation("io.github.evanrupert:excelkt:1.0.2")
}

Groovy DSL

repositories {
    mavenCentral()
}

dependencies {
    implementation 'io.github.evanrupert:excelkt:1.0.2'
}

Maven

In your pom.xml file make sure you have the following in your repositories:

<repository>
    <id>mavenCentral</id>
    <url>https://repo1.maven.org/maven2/</url>
</repository>

Then add the following to your dependencies:

<dependency>
    <groupId>io.github.evanrupert</groupId>
    <artifactId>excelkt</artifactId>
    <version>1.0.2</version>
</dependency>

Legacy Installation

For older versions of ExcelKt (v0.1.2 and before), which run on kotlin version 1.3.x and apache poi version 3.9, add the following to your gradle build file:

Kotlin DSL

repositories {
    jcenter()
    maven(url = "https://jitpack.io")
}

dependencies {
    implementation("com.github.EvanRupert:ExcelKt:v0.1.2")
}

Groovy DSL

repositories {
    jcenter()
    maven { url 'https://jitpack.io' }
}

dependencies {
    implementation 'com.github.evanrupert:excelkt:v0.1.2'
}

And use import excelkt.* instead of import io.github.evanrupert.excelkt.*

Quick Example

import io.github.evanrupert.excelkt.*
import org.apache.poi.ss.usermodel.FillPatternType
import org.apache.poi.ss.usermodel.IndexedColors

data class Customer(
    val id: String,
    val name: String,
    val address: String,
    val age: Int
)

fun findCustomers(): List<Customer> = listOf(
    Customer("1", "Robert", "New York", 32),
    Customer("2", "Bobby", "Florida", 12)
)

fun main() {
    workbook {
        sheet {
            row {
                cell("Hello, World!")
            }
        }

        sheet("Customers") {
            customersHeader()

            for (customer in findCustomers())
                row {
                    cell(customer.id)
                    cell(customer.name)
                    cell(customer.address)
                    cell(customer.age)
                }
        }

    }.write("test.xlsx")
}

fun Sheet.customersHeader() {
    val headings = listOf("Id", "Name", "Address", "Age")

    val headingStyle = createCellStyle {
        setFont(createFont {
            fontName = "IMPACT"
            color = IndexedColors.PINK.index
        })

        fillPattern = FillPatternType.SOLID_FOREGROUND
        fillForegroundColor = IndexedColors.AQUA.index
    }

    row(headingStyle) {
        headings.forEach { cell(it) }
    }
}

Supported cell data types

Cells support the following content types:

Formula
Boolean
Number
Date
Calendar
LocalDate
LocalDateTime

All other types will be converted to strings.

Example of all data types in use:

row {
    cell(Formula("A1 + A2"))
    cell(true)
    cell(12.2)
    cell(Date())
    cell(Calendar.getInstance())
    cell(LocalDate.now())
    cell(LocalDateTime.now())
}

Note on Dates

By default, dates will display as numbers in Excel. In order to display them correctly, create a cell style with the dataFormat set to your preferred format. See the following example:

row {
    val cellStyle = createCellStyle {
        dataFormat = xssfWorkbook.creationHelper.createDataFormat().getFormat("m/d/yy h:mm")
    }

    cell(Date(), cellStyle)
}