https://github.com/iamteppei/json-rule
A dynamic json validation rule utility
https://github.com/iamteppei/json-rule
Last synced: 10 days ago
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A dynamic json validation rule utility
- Host: GitHub
- URL: https://github.com/iamteppei/json-rule
- Owner: iamteppei
- License: apache-2.0
- Created: 2026-06-01T01:28:46.000Z (12 days ago)
- Default Branch: main
- Last Pushed: 2026-06-01T03:02:13.000Z (11 days ago)
- Last Synced: 2026-06-01T03:22:28.495Z (11 days ago)
- Language: Java
- Size: 37.1 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Security: SECURITY.md
Awesome Lists containing this project
README
# json-rule
[](https://github.com/iamteppei/json-rule/actions/workflows/ci.yml)
[](https://search.maven.org/artifact/io.github.iamteppei/json-rule)
[](https://www.apache.org/licenses/LICENSE-2.0)
[](https://openjdk.org/projects/jdk/21/)
[](#development)
[](https://sonarcloud.io/summary/new_code?id=iamteppei_json-rule)
[](https://sonarcloud.io/summary/new_code?id=iamteppei_json-rule)
JSON-based rule engine for decision processing.
This library lets you define rules in JSON and evaluate them against JSON-like input maps. It is designed for policy checks, event filtering, and lightweight decision flows where rules should be data, not code.
## Features
- JSON rule parser with nested object support
- Logical composition with $all and $any
- Rich predicate set for numbers, strings, lists, existence, null checks, and regex
- Expression helper support for ${path.to.value}-style extraction
- JUnit 5 test suite with JaCoCo coverage checks
- GitHub Actions pipeline with build, test, Sonar scan, and Maven Central publish job
## Requirements
- Java 21
- Maven 3.9+
## Installation
If you consume from Maven Central, add this dependency:
```xml
io.github.iamteppei
json-rule
LATEST_RELEASE
```
For local development:
```bash
mvn -B -ntp clean install
```
## Quick Start
```java
import io.abc.feature.decision_engine.core.rule.api.Rule;
import io.abc.feature.decision_engine.core.rule.api.RuleParser;
import io.abc.feature.decision_engine.core.rule.impl.MapParser;
import java.util.Map;
public class QuickStart {
public static void main(String[] args) {
String ruleJson = """
{
"detail": {
"state": ["in", ["running", "initializing"]]
},
"source": ["eq_ignore_case", "aws.ec2"]
}
""";
String inputJson = """
{
"source": "AWS.EC2",
"detail": {
"state": "running"
}
}
""";
RuleParser ruleParser = new RuleParser();
MapParser mapParser = new MapParser();
Rule rule = ruleParser.parse(ruleJson);
Map input = mapParser.parse(inputJson);
boolean matched = rule.test(input);
System.out.println("Matched: " + matched);
}
}
```
## Rule Syntax
### Simple condition
```json
{
"detail": {
"state": ["eq", "running"]
}
}
```
### Any/All composition
```json
{
"$all": [
{
"source": ["eq", "aws.ec2"]
},
{
"$any": [
{ "detail": { "state": ["eq", "running"] } },
{ "detail": { "state": ["eq", "initializing"] } }
]
}
]
}
```
### Supported operators
| Operator | Meaning |
| ------------------- | ----------------------------------------- |
| eq | Equals |
| ne | Not equals |
| gt | Greater than (BigDecimal) |
| ge | Greater than or equal (BigDecimal) |
| lt | Less than (BigDecimal) |
| le | Less than or equal (BigDecimal) |
| in | Source is in expected list |
| not_in | Source is not in expected list |
| contains | Collection/String contains expected value |
| not_contains | Negated contains |
| start_with | String starts with expected prefix |
| end_with | String ends with expected suffix |
| anything_start_with | String starts with any expected prefix |
| anything_end_with | String ends with any expected suffix |
| eq_ignore_case | Case-insensitive equals |
| matches | Regex full match |
| email | Valid email and expected boolean true |
| exists | Property exists and expected boolean true |
| non_null | Source is not null and not unknown |
| is_null | Source is null |
## Development
Run compile:
```bash
mvn -B -ntp clean compile
```
Run tests:
```bash
mvn -B -ntp test
```
Run tests with coverage gate:
```bash
mvn -B -ntp verify
```
JaCoCo rules currently enforce:
- Line coverage >= 60%
- Branch coverage >= 40%
## Community and Governance
- Code of Conduct: see [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md)
- Security Policy: see [SECURITY.md](SECURITY.md)
- License: see [LICENSE](LICENSE)
## Contributing
Contributions are welcome.
1. Fork the repository.
2. Create a feature branch.
3. Add or update tests for your change.
4. Run verify locally with Java 21.
5. Open a pull request with a clear description.
## License
This project is licensed under Apache License 2.0. See [LICENSE](LICENSE) for details.