TFT

Convert Java Properties to TOML

Modernize Java configuration by converting .properties files to structured TOML. This tool interprets dot-notation keys, creating nested tables for better organization.

Properties to TOML Converter

How the Properties to TOML Converter Works

This tool converts Java .properties files into TOML configuration format. Paste your KEY=value pairs and get properly structured TOML with sections, appropriate types, and clean formatting.

The converter parses .properties syntax, handles escaped characters, and reconstructs hierarchy from dot-notation keys. Properties like database.host and database.port become a [database] table in TOML with host and port keys.

Output is valid TOML with proper quoting, type inference (numbers, booleans, strings), and section organization. Copy into your config.toml file or use it to migrate Java projects to modern TOML configuration.

When You'd Actually Use This

Modernizing Java application configs

Moving from .properties to TOML? Convert existing configs while maintaining settings. TOML offers better structure and readability than flat properties.

Migrating Spring Boot applications

Spring Boot supports multiple config formats. Convert application.properties to TOML for cleaner hierarchical configuration. Same settings, better organization.

Unifying configs across languages

Your polyglot project uses different config formats. Standardize on TOML. Convert Java .properties, YAML, JSON configs to one consistent format.

Improving config readability

Large .properties files are hard to navigate. Convert to TOML with sections. Related settings grouped together. Easier to find and modify configurations.

Creating config documentation

TOML supports comments and structure. Convert .properties to TOML, add documentation comments. Better than .properties for documenting configuration options.

Building migration tools

Creating a config migration tool? Use this converter as reference. Understand how .properties maps to TOML for building automated migration scripts.

What to Know Before Using

Dot notation becomes sections.Keys like db.connection.host become [db.connection] section with host key. The converter detects hierarchy from dot-separated keys.

Type inference from string values..properties values are all strings. The converter guesses types: "42" → integer, "true" → boolean. Review and adjust types as needed.

Comments are preserved..properties comments (# or !) transfer to TOML comments (#). Use comments to document what each setting does for future maintainers.

Unicode escapes are converted.Java \uXXXX escapes become actual Unicode characters in TOML. TOML supports UTF-8 natively. No need for escape sequences.

Pro tip: Review the generated TOML structure. You might want to reorganize sections for better logical grouping. TOML's flexibility lets you improve on the original .properties organization.

Common Questions

How are keys grouped into sections?

Common prefixes become sections. database.url, database.user → [database] with url and user keys. The converter detects shared prefixes automatically.

What about properties without dots?

Flat keys (no dots) become top-level TOML keys. They appear before any sections. Mix of flat and hierarchical keys is valid in TOML.

Can I convert back from TOML to .properties?

This tool does .properties to TOML. For TOML to .properties, flatten sections to dot-notation keys. Many TOML libraries can help with this.

How are lists handled?

Java .properties doesn't have native lists. Common patterns: comma-separated or indexed keys. Converter detects these and creates TOML arrays.

What about property value escapes?

Java escapes (\n, \t, \\) are converted to TOML equivalents. TOML uses different escape sequences. The converter handles the translation.

Does Spring Boot support TOML?

Not natively. You'd need a custom PropertySource loader. Consider YAML instead—Spring Boot supports it natively and preserves structure like TOML.

How do I load TOML in Java?

Use a TOML library like tomllib-java or toml4j. Load and parse TOML, then map to your configuration objects. More work than .properties but doable.