Struct JsonItemReaderBuilder 

pub struct JsonItemReaderBuilder<I> { /* private fields */ }

Available on crate feature json only.

A builder for creating JSON item readers.

This builder provides a convenient way to configure and create a JsonItemReader with custom parameters like buffer capacity.

Examples

Reading from a string:

use spring_batch_rs::item::json::JsonItemReaderBuilder;
use spring_batch_rs::core::item::ItemReader;
use serde::Deserialize;
use std::io::Cursor;

#[derive(Debug, Deserialize)]
struct Person {
    name: String,
    age: u32,
    occupation: String,
}

// Sample JSON data
let json = r#"[
  {"name": "JohnDoe", "age": 30, "occupation": "SoftwareEngineer"},
  {"name": "JaneSmith", "age": 28, "occupation": "DataScientist"}
]"#;

// Create a reader
let cursor = Cursor::new(json);
let reader = JsonItemReaderBuilder::<Person>::new()
    .capacity(4096)  // Set a custom buffer capacity
    .from_reader(cursor);

// Read the items
let person1 = reader.read().unwrap().unwrap();
assert_eq!(person1.name, "JohnDoe");
assert_eq!(person1.age, 30);

let person2 = reader.read().unwrap().unwrap();
assert_eq!(person2.name, "JaneSmith");
assert_eq!(person2.occupation, "DataScientist");

The builder can also be used to read from files or any other source that implements the Read trait.

Implementations

impl<I: DeserializeOwned> JsonItemReaderBuilder<I>

pub fn new() -> JsonItemReaderBuilder<I>

Creates a new JSON item reader builder with default settings.

The default buffer capacity is 8 KB (8192 bytes).

Examples

use spring_batch_rs::item::json::JsonItemReaderBuilder;
use serde::Deserialize;

#[derive(Deserialize)]
struct Record {
    id: u32,
    value: String,
}

let builder = JsonItemReaderBuilder::<Record>::new();

pub fn capacity(self, capacity: usize) -> JsonItemReaderBuilder<I>

Sets the buffer capacity for the JSON reader.

A larger capacity can improve performance when reading large files, but uses more memory.

Examples

use spring_batch_rs::item::json::JsonItemReaderBuilder;
use serde::Deserialize;

#[derive(Deserialize)]
struct Record {
    id: u32,
    value: String,
}

// Create a builder with a 16 KB buffer
let builder = JsonItemReaderBuilder::<Record>::new()
    .capacity(16 * 1024);

pub fn from_reader<R: Read>(self, rdr: R) -> JsonItemReader<I, R>

Creates a JSON item reader from any source that implements the Read trait.

This allows reading from files, memory buffers, network connections, etc.

Examples

use spring_batch_rs::item::json::JsonItemReaderBuilder;
use spring_batch_rs::core::item::ItemReader;
use serde::Deserialize;
use std::io::Cursor;

#[derive(Debug, Deserialize)]
struct Order {
    id: String,
    customer: String,
    total: f64,
}

// Sample JSON data
let json = r#"[
  {"id": "ORD-001", "customer": "JohnDoe", "total": 125.50},
  {"id": "ORD-002", "customer": "JaneSmith", "total": 89.99}
]"#;

// Create a reader from a memory buffer
let cursor = Cursor::new(json);
let reader = JsonItemReaderBuilder::<Order>::new()
    .from_reader(cursor);

// Process the orders
let first_order = reader.read().unwrap().unwrap();
assert_eq!(first_order.id, "ORD-001");
assert_eq!(first_order.total, 125.50);

Trait Implementations

impl<I: Default> Default for JsonItemReaderBuilder<I>

fn default() -> JsonItemReaderBuilder<I>

Returns the “default value” for a type.