/redis-om-spring-skeleton-app

Redis OM Spring Skeleton App

Primary LanguageJava

🍀 Redis OM Spring Skeleton App

Redis OM Spring provides powerful repository and custom object-mapping abstractions built on top of the powerful Spring Data Redis (SDR) framework. This app is a simple started application using Redis OM Spring to map, manipulate and query some simple Spring Data models backed by RedisJSON documents.

Check out our workshop video for this project on YouTube.

Overview

The app provides a simple model Person:

  • id: An autogenerated String using ULIDs
  • firstName: A String representing their first or given name.
  • lastName: A String representing theirlast or surname.
  • age: An Integer representing their age in years.
  • personalStatement: A String representing a text personal statement containing facts or other biographical information.
  • homeLoc: A org.springframework.data.geo.Point representing the geo coordinates.
  • address: An entity of type Address representing the Person's postal address.
  • skills: A Set<String>, representing a collection of Strings representing skills the person has.

Mapping Entities to JSON

The Person model is annotated with @Document, this enables the models to be saved as RedisJSON documents. The individuals fields that will be used to create the entity search index are annotated with @Indexed or @Searchable (for full-text search capable text fields).

@Document
public class Person {
  @Id @Indexed
  private String id;

  @Indexed
  private String firstName;

  @Indexed
  private String lastName;

  @Indexed
  private Integer age;

  @Searchable
  private String personalStatement;

  @Indexed
  private Point homeLoc;

  @Indexed
  private Address address;

  @Indexed
  private Set<String> skills;
}

For example, saving the above object using a repository (see below) you'll get a JSON document under the Redis key com.redis.om.skeleton.models.Person:01FXD97WTHNYFQEA56YQ27BNQ6:

{
  "id": "01FXD97WTHNYFQEA56YQ27BNQ6",
  "firstName": "Elizabeth",
  "lastName": "Olsen",
  "age": 32,
  "personalStatement": "You Guys Know I Can Move Things With My Mind, Right?",
  "homeLoc": "40.6976701,-74.2598641",
  "address": {
    "houseNumber": "20",
    "street": "W 34th St",
    "city": "New York",
    "state": "NY",
    "postalCode": "10001",
    "country": "US"
  },
  "skills": [
    "loyalty",
    "magic"
  ]
}

The resulting JSON has a generated value for the id field using a ULIDs. Note that the homeLoc field is mapped to the lon-lat format expected by Redis, and the set of skills is mapped into a JSON array.

The SpringBoot App

Use the @EnableRedisDocumentRepositories annotation to scan for @Document annotated Spring models, Inject repositories beans implementing RedisDocumentRepository which you can use for CRUD operations and custom queries (all by declaring Spring Data Query Interfaces):

@SpringBootApplication
@EnableRedisDocumentRepositories(basePackages = "com.redis.om.skeleton.*")
public class SkeletonApplication {
}

🧰 The Repository

Redis OM Spring data repository's goal, like other Spring Data repositories, is to significantly reduce the amount of boilerplate code required to implement data access. Simply create a Java interface that extends RedisDocumentRepository that takes the domain class to manage as well as the ID type of the domain class as type arguments. RedisDocumentRepository extends Spring Data's PagingAndSortingRepository.

Declare query methods on the interface. You can both, expose CRUD methods or create declarations for complex queries that Redis OM Spring will fullfil at runtime:

public interface PeopleRepository extends RedisDocumentRepository<Person, String> {
  // Find people by age range
  Iterable<Person> findByAgeBetween(int minAge, int maxAge);

  // Draws a circular geofilter around a spot and returns all people in that radius
  Iterable<Person> findByHomeLoc(Point point, Distance distance);

  // Find people by their first and last name
  Iterable<Person> findByFirstNameAndLastName(String firstName, String lastName);

  // Performs full text search on a person's personal Statement
  Iterable<Person> searchByPersonalStatement(String text);

  // ...
}

The repository proxy has two ways to derive a store-specific query from the method name:

  • By deriving the query from the method name directly.
  • By using a manually defined query using the @Query or @Aggregation annotations.

CRUD Operations

You can inject a Repository and perform the basic CRUD operations as well as any custom queries you've defined:

@Autowired
PeopleRepository repo;

@PostMapping("new")
Person create(@RequestBody Person newPerson) {
  return repo.save(newPerson);
}

🚤 Querying with Entity Streams

Redis OM Spring Entity Streams provides a Java 8 Streams interface to Query Redis JSON documents using RediSearch. Entity Streams allow you to process data in a typesafe declarative way similar to SQL statements. Streams can be used to express a query as a chain of operations.

Entity Streams in Redis OM Spring provide the same semantics as Java 8 streams. Streams can be made of Redis Mapped entities (@Document) or one or more properties of an Entity. Entity Streams progressively build the query until a terminal operation is invoked (such as collect). Whenever a Terminal operation is applied to a Stream, the Stream cannot accept additional operations to its pipeline and it also means that the Stream is started.

Let's start with a simple example, a Spring @Service which includes EntityStream to query for instances of the mapped class Person:

package com.redis.om.skeleton.services;

import java.util.stream.Collectors;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.redis.om.skeleton.models.Person;
import com.redis.om.skeleton.models.Person$;
import com.redis.om.spring.search.stream.EntityStream;

@Service
public class PeopleService {
  @Autowired
  EntityStream entityStream;

  // Find all people
  public Iterable<Person> findAllPeople(int minAge, int maxAge) {
    return entityStream //
        .of(Person.class) //
        .collect(Collectors.toList());
  }

}

The EntityStream is injected into the PeopleService using @Autowired. We can then get a stream for Person objects by using entityStream.of(Person.class). At this point the stream represents the equivalent of a SELECT * FROM Person on a relational database. The call to collect will then execute the underlying query and return a collection of all Person objects in Redis.

👭 Entity Meta-model

To produce more elaborate queries, you're provided with a generated meta-model, which is a class with the same name as your model but ending with a dollar sign. In the example below, our entity model is Person therefore we get a meta-model named Person$. With the meta-model you have access to the operations related to the underlying search engine field. For example, in the example we have an age property which is an integer. Therefore our metamodel has an AGE property which has numeric operations we can use with the stream's filter method such as between.

// Find people by age range
public Iterable<Person> findByAgeBetween(int minAge, int maxAge) {
  return entityStream //
      .of(Person.class) //
      .filter(Person$.AGE.between(minAge, maxAge)) //
      .sorted(Person$.AGE, SortOrder.ASC) //
      .collect(Collectors.toList());
}

In this example we also make use of the Streams sorted method to declare that our stream will be sorted by the Person$.AGE in ASCending order.

💾 Get the Source Code

Clone the repository from GitHub:

$ git clone https://github.com/redis-developer/redis-om-spring-skeleton-app
$ cd redis-om-spring-skeleton-app

🚀 Launch Redis

🥞Redis Stack on Docker Locally

Redis OM Spring relies on the power of the [RediSearch][redisearch-url] and [RedisJSON][redis-json-url] modules. We have provided a docker compose YAML file for you to quickly get started. To launch the docker compose application, on the command line (or via Docker Desktop), clone this repository and run (from the root folder):

docker compose up

This launches Redis Stack; Redis Stack Server on port 6379, and Redis Insight 8001.

🌥️Redis Cloud

If you're using Redis Enterprise Cloud, you'll need the hostname, port number, and password for your database. Use these to set the application.properties configuration like this:

spring.data.redis.host=<host>
spring.data.redis.port=<port>
spring.data.redis.password=<password>
spring.data.redis.username=<username>

For example if your Redis Enterprise Cloud database is at port 9139 on host enterprise.redis.com and your password is 5uper53cret then you'd set REDIS_OM_URL as follows:

spring.data.redis.host=enterprise.redis.com
spring.data.redis.port=9139
spring.data.redis.password=5uper53cret
spring.data.redis.username=default

📝 Prerequisites

  • Java 17 or higher
  • Spring Boot 3.0.2
  • A Redis database with the RediSearch module version TODO or higher installed. We've provided a docker-compose.yml with Redis Stack for this. You can also sign up for a free 30Mb database with Redis Enterprise Cloud - be sure to check the box to configure a Redis Stack instance, follow this guide.
  • curl, or Postman - to send HTTP requests to the application. We'll provide examples using curl in this document.
  • Optional: RedisInsight, a free data visualization and database management tool for Redis. When downloading RedisInsight, be sure to select version 2.x.

🏃Run the App

./mvnw spring-boot:run

🧭Interact with the API

You can interact with the API directly with CURL or through the Swagger interface.