Struct CsvItemReader 

pub struct CsvItemReader<R: Read> { /* private fields */ }

Available on crate feature csv only.

A CSV item reader that implements the ItemReader trait.

This reader deserializes CSV data into Rust structs row by row using Serde’s deserialization capabilities. It can process CSV data from files, strings, or any source implementing the Read trait.

Type Parameters

• R: The type of reader providing the CSV data. Must implement Read.

Implementation Details

• Uses a RefCell to provide interior mutability for the CSV record iterator
• Requires DeserializeOwned for types that can be deserialized from CSV rows
• Automatically converts CSV parsing errors into Spring Batch errors
• Allows streaming data processing without loading the entire file into memory

Examples

use spring_batch_rs::item::csv::csv_reader::CsvItemReaderBuilder;
use spring_batch_rs::core::item::ItemReader;
use serde::Deserialize;

#[derive(Debug, Deserialize)]
struct Record {
    name: String,
    value: i32,
}

// Create a CSV string
let data = "\
name,value
foo,123
bar,456
";

// Build a reader
let reader = CsvItemReaderBuilder::<Record>::new()
    .has_headers(true)
    .from_reader(data.as_bytes());

// Read the first record
let record: Record = reader.read().unwrap().unwrap();
assert_eq!(record.name, "foo");
assert_eq!(record.value, 123);

// Read the second record
let record: Record = reader.read().unwrap().unwrap();
assert_eq!(record.name, "bar");
assert_eq!(record.value, 456);

// No more records - explicitly use Record type again
assert!(ItemReader::<Record>::read(&reader).unwrap().is_none());

Trait Implementations

impl<I: DeserializeOwned, R: Read> ItemReader<I> for CsvItemReader<R>

fn read(&self) -> ItemReaderResult<I>

Reads the next item from the CSV file.

This method reads and deserializes the next row from the CSV source. The row is converted to the specified type T using Serde’s deserialization.

Deserialization Process

1. Gets the next record from the CSV iterator
2. If no more records, returns Ok(None)
3. Deserializes the record to type T using serde
4. Wraps errors in the Spring Batch error system

Returns

• Ok(Some(record)) if a record is successfully read
• Ok(None) if there are no more records to read
• Err(BatchError::ItemReader(error)) if an error occurs during reading or deserialization

Examples

use spring_batch_rs::item::csv::csv_reader::CsvItemReaderBuilder;
use spring_batch_rs::core::item::ItemReader;
use serde::Deserialize;

#[derive(Debug, Deserialize)]
struct Person {
    name: String,
    age: u8,
}

let data = "name,age\nAlice,30\nBob,25";
let reader = CsvItemReaderBuilder::<Person>::new()
    .has_headers(true)
    .from_reader(data.as_bytes());

// Read all people
let mut people: Vec<Person> = Vec::new();
while let Some(person) = reader.read().unwrap() {
    people.push(person);
}

assert_eq!(people.len(), 2);
assert_eq!(people[0].name, "Alice");
assert_eq!(people[0].age, 30);