sdk-connection-java.java

/**
 * Couchbase SDK connection singleton — Java
 * Copy and adapt for your application.
 *
 * Dependencies (Maven):
 *   <dependency>
 *     <groupId>com.couchbase.client</groupId>
 *     <artifactId>java-client</artifactId>
 *     <version>3.7.4</version>
 *   </dependency>
 */
package com.example;

import com.couchbase.client.java.Cluster;
import com.couchbase.client.java.ClusterOptions;
import com.couchbase.client.java.Collection;
import com.couchbase.client.java.env.ClusterEnvironment;
import com.couchbase.client.core.env.TimeoutConfig;

import java.time.Duration;

public class CouchbaseConnection {

    // --- Configuration ---
    private static final String CB_HOST       = "localhost";          // or "cb.xxxxx.cloud.couchbase.com" for Capella
    private static final String CB_USER       = "app-service-user";
    private static final String CB_PASSWORD   = "AppSecret123!";
    private static final String CB_BUCKET     = "myapp";
    private static final String CB_SCOPE      = "_default";
    private static final String CB_COLLECTION = "_default";

    private static volatile Cluster    cluster;
    private static volatile Collection collection;

    private CouchbaseConnection() {}

    /** Return the singleton Collection, initializing the cluster on first call. */
    public static Collection getCollection() {
        if (collection == null) {
            synchronized (CouchbaseConnection.class) {
                if (collection == null) {
                    init();
                }
            }
        }
        return collection;
    }

    /** Return the singleton Cluster (needed for queries and transactions). */
    public static Cluster getCluster() {
        getCollection(); // ensures cluster is initialized
        return cluster;
    }

    private static void init() {
        ClusterEnvironment env = ClusterEnvironment.builder()
            .timeoutConfig(TimeoutConfig.builder()
                .connectTimeout(Duration.ofSeconds(10))
                .kvTimeout(Duration.ofMillis(2500))
                .queryTimeout(Duration.ofSeconds(75))
                .searchTimeout(Duration.ofSeconds(75))
                .build())
            .build();

        // Use "couchbases://" for TLS (required for Capella, recommended for production)
        cluster = Cluster.connect(
            CB_HOST,
            ClusterOptions.clusterOptions(CB_USER, CB_PASSWORD).environment(env)
        );
        cluster.waitUntilReady(Duration.ofSeconds(10));

        collection = cluster
            .bucket(CB_BUCKET)
            .scope(CB_SCOPE)
            .collection(CB_COLLECTION);
    }

    /** Call on application shutdown to release resources. */
    public static void close() {
        if (cluster != null) {
            cluster.disconnect();
        }
    }

    // --- Usage example ---
    public static void main(String[] args) {
        Collection col     = getCollection();
        Cluster    cluster = getCluster();

        // KV upsert
        col.upsert("doc_1", com.couchbase.client.java.json.JsonObject.create()
            .put("type", "example")
            .put("value", 42));

        // KV get
        var result = col.get("doc_1");
        System.out.println(result.contentAsObject());

        // SQL++ query
        var rows = cluster.query(
            "SELECT * FROM `myapp`._default._default WHERE type = $type LIMIT 5",
            com.couchbase.client.java.query.QueryOptions.queryOptions()
                .parameters(com.couchbase.client.java.json.JsonObject.create().put("type", "example"))
        );
        rows.rowsAsObject().forEach(System.out::println);

        close();
    }
}