Data Validator

About

Data Validator is a library that can be used to check the correctness of any input data.

Run checkstyle

make lint

Make JaCoCo Report

make report

Launch the Test

make test

Demo of the App

Validator validator = new Validator(); // only once create Validator and reuse it after

StringSchema

This schema validate String objects. To choose this schema write:

StringSchema schema = validator.string();

StringSchema has three validation methods:

• required() - makes the fields required and limits the possibility to use null or empty String.
• minLength() - adds a minimum length constraint for the String. The String must be equal or longer than a specified number. Requires an integer parameter of minimum length.
• contains() - adds a String content constraint. The String must contain a substring passed in the method parameter.

Usage example:

StringSchema schema = validator.string().required().minLength(5).contains("hex");
schema.isValid(""); // false
schema.isValid("hex"); // false
schema.isValid("telxeh"); // false
schema.isValid("hexlet"); // true

NumberSchema

This schema validate Integer objects. To choose this schema write:

NumberSchema schema = validator.number();

NumberSchema has three validation methods:

• required() - makes the fileds required and limits the possibility to use null.
• positive() - adds a constraint to use negative numbers.
• range() - adds a range constraint (inclusive). Requires two integer parameters of the first and the last numbers of range.

Usage example:

NumberSchema schema = validator.number().required().positive().range(2, 7);
schema.isValid(-5); // false
schema.isValid(8); // false
schema.isValid(5); // true
schema.isValid(7); // true

MapSchema

This schema validate Map objects. To schoose this schema write:

MapSchema schema = validator.map();

MapSchema has three validation methods:

• required() - makes the fields required and limits the possibility to use null.
• sizeOf() - adds a map size constraint. The K-V count must be equal to the number passed in the method parameter.
• shape() - adds constraints to map values. Accepts as a parameter a map of keys whose values need to be validated and schemas that would validate the values.

Usage example:

Map<String, BaseSchema<Integer>> schemas = new HashMap<>();
schemas.put("first", validator.number());
schemas.put("second", validator.number().positive());
schemas.put("third", validator.number().positive().range(3, 8));

schema.shape(schemas);

Map<String, Integer> number1 = new HashMap<>();
number1.put("first", 8);
number1.put("second", null);
number1.put("third", 5);
assertTrue(mapSchema.isValid(number1));

Map<String, Integer> number2 = new HashMap<>();
number2.put("first", 6);
number2.put("second", -5);
number1.put("third", 2);
assertFalse(mapSchema.isValid(number2));
}

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