filters-query

filters-query can translate your query string to JPA criteria, Lucene query and Java predicates, which empowers you build complex query API fast.

1.Syntax

filter by <criterias> [offset <number>] [limit <number>] [sort by <orders>]

Criterias

filters-query supports following operators:

• between: exampleField between [,130]
• empty, not empty: exampleField = empty, exampleField != empty
• starts with: exampleField startsWith "prefix"
• ends with: exampleField endsWith "suffix"
• like: exampleField like "asd"
• equal, not equal: =, !=
• gt, get: >, >=
• lt, let: <, <=
• in: exampleField in ("Value1", "Value2")

data types:

• number: 130, 130.22
• boolean: true, false
• string: "asd"
• null: null

bool expression: a = 123 and (b like "value" or c in [1,3,8])

Pagination

You can use limit and offset to do page query, like: filter by id > 10 offset 20 limit 10, this query means requesting the page 2 (index from 0).

Sorts

Examples:

• sort by id desc: sort by id desc
• sort by multiple fields: filter by () sort by id desc, name asc

2.Integrate with JPA

Maven Dep:

<dependency>
  <groupId>org.luncert.filters-query</groupId>
  <version>1.0-SNAPSHOT</version>
  <artifactId>jpa-impl</artifactId>
</dependency>

Define entity according to JPA requirements:

@Entity
class TestEntity {

  @Id
  private Long id;

  private String name;
}

Impl search engine:

import jakarta.persistence.EntityManager;
import org.luncert.filtersquery.jpaimpl.JpaFiltersQueryEngine;
import org.luncert.filtersquery.jpaimpl.model.LogHeader;
import org.springframework.stereotype.Component;

@Component
public class TestEntitySearchImpl extends JpaFiltersQueryEngine<TestEntity> {

  public LogHeaderSearchImpl(EntityManager em) {
    super(em);
  }
}

Process query:

searchEngine.searchPages("filter by id < 10 offset 5 limit 5");

3.Translate query to predicates

Maven Dep:

<dependency>
  <groupId>org.luncert.filters-query</groupId>
  <version>1.0-SNAPSHOT</version>
  <artifactId>predicate-impl</artifactId>
</dependency>

Define model:

class TestModel {

  private Long id;

  private String name;
}

Usage:

List<TestModel> input = ...;
Predicate<TestModel> predicate = PredicateFiltersQueryEngine
  .buildQuery(criteria, TestModel.class);
List<TestModel> filtered = data.stream().filter(predicate);