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Feature Flags Reference

Spring Batch RS uses feature flags to enable optional functionality. This keeps the core library lean while allowing you to opt into specific capabilities.

Core Features (Always Available)

Section titled “Core Features (Always Available)”

These features are always included and require no feature flags:

Core Traits

ItemReader, ItemWriter, ItemProcessor, Tasklet

Job & Step

JobBuilder, StepBuilder, execution management

Error Handling

BatchError, fault tolerance, skip/retry logic

Logger Writer

LoggerWriter for debugging output

File Format Features

Section titled “File Format Features”

CSV

Section titled “CSV”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["csv"] }

Provides:

  • CsvItemReader<R> - Read CSV files and strings
  • CsvItemWriter<O, W> - Write CSV files

Use for:

  • Comma/tab/custom-delimited files
  • Headers or headerless CSV
  • Data import/export pipelines

Dependencies:

  • csv crate

JSON

Section titled “JSON”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["json"] }

Provides:

  • JsonItemReader<I, R> - Streaming JSON array reader
  • JsonItemWriter<O, W> - JSON array writer with pretty-printing

Use for:

  • REST API data processing
  • Configuration file manipulation
  • JSON data transformation

Dependencies:

  • serde_json crate

XML

Section titled “XML”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["xml"] }

Provides:

  • XmlItemReader<R, I> - Extract elements by tag name
  • XmlItemWriter<O, W> - Generate XML documents

Use for:

  • SOAP/XML API integration
  • RSS/Atom feed processing
  • Legacy XML data migration

Dependencies:

  • quick-xml crate
  • serde-xml-rs crate

Database Features

Section titled “Database Features”

PostgreSQL

Section titled “PostgreSQL”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["rdbc-postgres"] }
sqlx = { version = "0.7", features = ["runtime-tokio-native-tls", "postgres"] }

Provides:

  • PostgresRdbcItemReader<I> - Paginated PostgreSQL queries
  • PostgresItemWriter<O> - Bulk PostgreSQL inserts

Use for:

  • Reading from PostgreSQL tables
  • ETL from PostgreSQL to other systems
  • Bulk data loading

Dependencies:

  • sqlx with PostgreSQL support
  • tokio async runtime

MySQL

Section titled “MySQL”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["rdbc-mysql"] }
sqlx = { version = "0.7", features = ["runtime-tokio-native-tls", "mysql"] }

Provides:

  • MysqlRdbcItemReader<I> - Paginated MySQL queries
  • MysqlItemWriter<O> - Bulk MySQL inserts

Use for:

  • MySQL/MariaDB data extraction
  • Database migrations
  • Reporting queries

Dependencies:

  • sqlx with MySQL support
  • tokio async runtime

SQLite

Section titled “SQLite”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["rdbc-sqlite"] }
sqlx = { version = "0.7", features = ["runtime-tokio-native-tls", "sqlite"] }

Provides:

  • SqliteRdbcItemReader<I> - Paginated SQLite queries
  • SqliteItemWriter<O> - Bulk SQLite inserts

Use for:

  • Embedded database processing
  • Local data stores
  • Testing and development

Dependencies:

  • sqlx with SQLite support
  • tokio async runtime

NoSQL Features

Section titled “NoSQL Features”

MongoDB

Section titled “MongoDB”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["mongodb"] }
mongodb = "2.8"

Provides:

  • MongodbItemReader<I> - Cursor-based MongoDB queries
  • MongodbItemWriter<O> - Bulk MongoDB inserts

Use for:

  • Document database processing
  • MongoDB data migration
  • Collection transformations

Dependencies:

  • mongodb official driver
  • Requires WithObjectId trait implementation

ORM Feature

Section titled “ORM Feature”

SeaORM

Section titled “SeaORM”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["orm"] }
sea-orm = { version = "0.12", features = ["sqlx-postgres", "runtime-tokio-native-tls"] }

Provides:

  • OrmItemReader<I> - Read using SeaORM entities
  • OrmItemWriter<O> - Write using SeaORM entities

Use for:

  • Type-safe database access
  • Working with existing SeaORM models
  • Complex query building

Dependencies:

  • sea-orm with appropriate database backend

Tasklet Features

Section titled “Tasklet Features”

ZIP Compression

Section titled “ZIP Compression”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["zip"] }

Provides:

  • ZipTasklet - Compress files and directories

Capabilities:

  • Configurable compression levels (0-9)
  • File filtering with glob patterns
  • Directory structure preservation
  • Single file or directory compression

Use for:

  • Backup operations
  • Log file archival
  • Report packaging

Dependencies:

  • zip crate

FTP Transfers

Section titled “FTP Transfers”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["ftp"] }

Provides:

  • FtpTasklet - Upload/download via FTP/FTPS

Capabilities:

  • FTP and FTPS (TLS) support
  • Upload and download operations
  • Authentication support
  • Connection management

Use for:

  • File distribution
  • Remote backup
  • Legacy system integration

Dependencies:

  • ftp crate

Testing Feature

Section titled “Testing Feature”

Fake Data Generation

Section titled “Fake Data Generation”
[dependencies]
spring-batch-rs = { version = "0.1", features = ["fake"] }

Provides:

  • PersonReader - Generate fake person data
  • Person struct with realistic test data

Use for:

  • Testing batch jobs
  • Development without real data
  • Performance testing

Dependencies:

  • fake crate

Feature Combinations

Section titled “Feature Combinations”

Common Combinations

Section titled “Common Combinations”

File Processing 

features = ["csv", "json", "xml"]

Process all common file formats

Database ETL 

features = ["rdbc-postgres", "rdbc-mysql", "csv", "json"]

Database to file exports and imports

Complete Pipeline 

features = ["csv", "json", "rdbc-postgres", "zip", "ftp"]

End-to-end data pipeline with delivery

NoSQL Processing 

features = ["mongodb", "json", "csv"]

MongoDB data transformation

Dependency Impact

Section titled “Dependency Impact”

Compile Time

Section titled “Compile Time”
Feature CombinationAdditional Compile Time
Core onlyBaseline
+ csv, json, xml+10-15 seconds
+ Single database+30-45 seconds (sqlx)
+ All databases+45-60 seconds
+ mongodb+20-30 seconds
+ All features+60-90 seconds

Binary Size

Section titled “Binary Size”
Feature CombinationApproximate Size (Release)
Core only~1 MB
+ File formats~2 MB
+ Single database~4-5 MB
+ All databases~7-9 MB
+ All features~10-12 MB

Advanced Configuration

Section titled “Advanced Configuration”

Feature-Gated Code

Section titled “Feature-Gated Code”

Use conditional compilation for feature-specific code:

#[cfg(feature = "csv")]
use spring_batch_rs::item::csv::CsvItemReaderBuilder;


#[cfg(feature = "rdbc-postgres")]
use spring_batch_rs::item::rdbc::postgres::PostgresItemWriterBuilder;


fn create_reader() -> Box<dyn ItemReader<MyType>> {
    #[cfg(feature = "csv")]
    {
        Box::new(CsvItemReaderBuilder::new().from_path("data.csv").unwrap())
    }


    #[cfg(not(feature = "csv"))]
    {
        panic!("CSV feature not enabled")
    }
}

Runtime Feature Detection

Section titled “Runtime Feature Detection”

Check available features at runtime:

fn check_features() {
    println!("CSV support: {}", cfg!(feature = "csv"));
    println!("JSON support: {}", cfg!(feature = "json"));
    println!("PostgreSQL support: {}", cfg!(feature = "rdbc-postgres"));
}

Migration Guide

Section titled “Migration Guide”

Upgrading from Minimal to Full Features

Section titled “Upgrading from Minimal to Full Features”

Before:

[dependencies]
spring-batch-rs = "0.1"

After:

[dependencies]
spring-batch-rs = { version = "0.1", features = ["csv", "json", "rdbc-postgres"] }
sqlx = { version = "0.7", features = ["runtime-tokio-native-tls", "postgres"] }

Removing Unused Features

Section titled “Removing Unused Features”

If your project grows and you want to optimize:

  1. Audit your imports and identify which readers/writers you use
  2. Map them to feature flags using the tables above
  3. Remove unused features from Cargo.toml
  4. Run cargo clean and rebuild

Feature Request Guidelines

Section titled “Feature Request Guidelines”

Can’t find a feature you need? We welcome contributions!

See Also

Section titled “See Also”