Momento Java Client Library

⚠️ Experimental SDK ⚠️

This is an official Momento SDK, but the API is in an early experimental stage and subject to backward-incompatible changes. For more info, click on the experimental badge above.

Java client SDK for Momento Serverless Cache: a fast, simple, pay-as-you-go caching solution without any of the operational overhead required by traditional caching solutions!

Getting Started 🏃

Requirements

A Momento Auth Token is required, you can generate one using the Momento CLI
At least the java 8 run time installed
mvn or gradle for downloading the sdk

Examples

Ready to dive right in? Just check out the examples directory for complete, working examples of how to use the SDK.

Installation

Gradle

Add our mvn repository to your gradle.build.kts file and sdk as a dependency

buildscript {
    repositories {
        mavenCentral()
        
        maven("https://momento.jfrog.io/artifactory/maven-public")
    }

    dependencies {
            implementation("momento.sandbox:momento-sdk:0.20.0")
    }
}

Maven

Add our mvn repository to your pom.xml file and sdk as a dependency

<project>
    ...
    <repositories>
        <repository>
            <id>momento-sdk</id>
            <url>https://momento.jfrog.io/artifactory/maven-public</url>
        </repository>
    </repositories>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>momento.sandbox</groupId>
                <artifactId>momento-sdk</artifactId>
                <version>0.20.0</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
    ...
</project>

Usage

Checkout our examples directory for complete examples of how to use the SDK.

Here is a quickstart you can use in your own project:

package momento.client.example;

import java.util.Optional;
import momento.sdk.SimpleCacheClient;
import momento.sdk.exceptions.AlreadyExistsException;
import momento.sdk.messages.CacheGetResponse;
import momento.sdk.messages.CacheInfo;
import momento.sdk.messages.ListCachesResponse;

public class MomentoCacheApplication {

  private static final String MOMENTO_AUTH_TOKEN = System.getenv("MOMENTO_AUTH_TOKEN");
  private static final String CACHE_NAME = "cache";
  private static final String KEY = "key";
  private static final String VALUE = "value";
  private static final int DEFAULT_ITEM_TTL_SECONDS = 60;

  public static void main(String[] args) {
    printStartBanner();
    try (SimpleCacheClient simpleCacheClient =
        SimpleCacheClient.builder(MOMENTO_AUTH_TOKEN, DEFAULT_ITEM_TTL_SECONDS).build()) {

      createCache(simpleCacheClient, CACHE_NAME);

      listCaches(simpleCacheClient);

      System.out.println(String.format("Setting key=`%s` , value=`%s`", KEY, VALUE));
      simpleCacheClient.set(CACHE_NAME, KEY, VALUE);

      System.out.println(String.format("Getting value for key=`%s`", KEY));

      CacheGetResponse getResponse = simpleCacheClient.get(CACHE_NAME, KEY);
      System.out.println(String.format("Lookup resulted in: `%s`", getResponse.status()));
      System.out.println(
          String.format("Looked up value=`%s`", getResponse.string().orElse("NOT FOUND")));
    }
    printEndBanner();
  }

  private static void createCache(SimpleCacheClient simpleCacheClient, String cacheName) {
    try {
      simpleCacheClient.createCache(cacheName);
    } catch (AlreadyExistsException e) {
      System.out.println(String.format("Cache with name `%s` already exists.", cacheName));
    }
  }

  private static void listCaches(SimpleCacheClient simpleCacheClient) {
    System.out.println("Listing caches:");
    Optional<String> token = Optional.empty();
    do {
      ListCachesResponse listCachesResponse = simpleCacheClient.listCaches(token);
      for (CacheInfo cacheInfo : listCachesResponse.caches()) {
        System.out.println(cacheInfo.name());
      }
      token = listCachesResponse.nextPageToken();
    } while (token.isPresent());
  }

  private static void printStartBanner() {
    System.out.println("******************************************************************");
    System.out.println("*                      Momento Example Start                     *");
    System.out.println("******************************************************************");
  }

  private static void printEndBanner() {
    System.out.println("******************************************************************");
    System.out.println("*                       Momento Example End                      *");
    System.out.println("******************************************************************");
  }
}

Error Handling

Coming soon

Tuning