redisjson.md

RedisJSON Jedis Quick Start

Jedis supports RedisJSON and RediSearch.

The latest versions of RedisJSON let you store, manipulate, index, and query JSON. To use these features with Jedis, you'll need to use the UnifiedJedis interface or a sub-class of it.

Let's see how this works.

Connecting with UnifiedJedis

First, let's create a UnifiedJedis instance:

UnifiedJedis client = new JedisPooled(Protocol.DEFAULT_HOST, 6479);

Now we can start working with JSON. For these examples, we'll be using [GSON] (https://github.com/google/gson) to handle the serialization of POJOs to JSON.

Creating JSON documents

Suppose we're building an online learning platform, and we want to represent students. Let's create a POJO to represent our students:

private class Student {
    private String firstName;
    private String lastName;

    public Student(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public String getFirstName() {
      return firstName;
    }

    public String getLastName() {
      return lastName;
    }
}

Now we can create some students and store them in Redis as JSON":

Student maya = new Student("Maya", "Jayavant");
client.jsonSet("student:111", maya);

Student oliwia = new Student("Oliwia", "Jagoda");
client.jsonSet("student:112", oliwia);

Querying and indexing JSON

If we want to be able to query this JSON, we'll need to create an index. Let's create an index on the "firstName" and "lastName" fields.

1. We define which fields to index ("firstName" and "lastName").
2. We set up the index definition to recognize JSON and include only those documents whose key starts with "student:".
3. Then we actually create the index, called "student-index", by calling ftCreate ().

Schema schema = new Schema().addTextField("$.firstName", 1.0).addTextField("$" +
            ".lastName", 1.0);
IndexDefinition rule = new IndexDefinition(IndexDefinition.Type.JSON)
        .setPrefixes(new String[]{"student:"});
client.ftCreate("student-index",
            IndexOptions.defaultOptions().setDefinition(rule),
            schema);

With an index now defined, we can query our JSON. Let's find all students whose name begins with "maya":

Query q = new Query("@\\$\\" + ".firstName:maya*");
SearchResult mayaSearch = client.ftSearch("student-index", q);

We can then iterate over our search results:

List<Document> docs = mayaSearch.getDocuments();
for (Document doc : docs) {
   System.out.println(doc);
}

This example just scratches the surface. You can atomically manipulate JSON documents and query them in a variety of ways. See the RedisJSON docs, the RediSearch docs, and our course, "Querying, Indexing, and Full-text Search in Redis", for a lot more examples.