CSV Processing

CSV (Comma-Separated Values) is one of the most common data formats for batch processing. Spring Batch RS provides powerful tools for reading and writing CSV files with full support for headers, custom delimiters, and data transformation.

Quick Start

use spring_batch_rs::item::csv::{CsvItemReaderBuilder, CsvItemWriterBuilder};

// Read CSV with headers
let reader = CsvItemReaderBuilder::<Product>::new()
    .has_headers(true)
    .from_path("products.csv");

// Write CSV with headers
let writer = CsvItemWriterBuilder::<Product>::new()
    .has_headers(true)
    .from_path("output.csv");

Features

Header handling: Automatic header detection and generation
Custom delimiters: Support for comma, semicolon, tab, and any custom delimiter
Data transformation: Apply processors to transform data during processing
Fault tolerance: Skip invalid records with configurable limits
Type safety: Automatic deserialization into Rust structs using serde

Complete Example

The csv_processing example demonstrates:

Basic CSV to CSV: Copy CSV data with pass-through processing
CSV to JSON with transformation: Apply discounts during conversion
Custom delimiters: Process semicolon-separated files
Fault tolerance: Handle malformed records gracefully

Run the Example

cargo run --example csv_processing --features csv,json

API Reference

CsvItemReaderBuilder

Method	Description
`has_headers(bool)`	Enable/disable header row parsing (default: `false`)
`delimiter(u8)`	Set field delimiter (default: `,`)
`from_reader(R)`	Create reader from any `Read` source
`from_path(P)`	Create reader from file path

CsvItemWriterBuilder

Method	Description
`has_headers(bool)`	Include header row in output (default: `false`)
`delimiter(u8)`	Set field delimiter (default: `,`)
`from_writer(W)`	Create writer for any `Write` destination
`from_path(P)`	Create writer to file path

Common Patterns

Reading with Custom Delimiter

// European CSV format with semicolons
let reader = CsvItemReaderBuilder::<Record>::new()
    .has_headers(true)
    .delimiter(b';')
    .from_path("data.csv");

Writing Without Headers

// Raw data export without header row
let writer = CsvItemWriterBuilder::<Record>::new()
    .has_headers(false)
    .from_path("export.csv");

Error Handling with Skip Limit

let step = StepBuilder::new("csv-step")
    .chunk::<Input, Output>(100)
    .reader(&reader)
    .processor(&processor)
    .writer(&writer)
    .skip_limit(10)  // Allow up to 10 parsing errors
    .build();