title	description	ms.service	author	ms.author	ms.subservice	ms.devlang	ms.topic	ms.date	ms.custom
Java app with Azure Cosmos DB Cassandra API using Java 4.0 SDK	This quickstart shows how to use the Azure Cosmos DB Cassandra API to create a profile application with the Azure portal and Java 4.0 SDK.	cosmos-db	TheovanKraay	thvankra	cosmosdb-cassandra	java	quickstart	05/18/2020	seo-java-august2019, seo-java-september2019, devx-track-java

Quickstart: Build a Java app to manage Azure Cosmos DB Cassandra API data (v4 Driver)

[!div class="op_single_selector"]

.NET

.NET Core

Java v3

Java v4

Node.js

Python

In this quickstart, you create an Azure Cosmos DB Cassandra API account, and use a Cassandra Java app cloned from GitHub to create a Cassandra database and container using the v4.x Apache Cassandra drivers for Java. Azure Cosmos DB is a multi-model database service that lets you quickly create and query document, table, key-value, and graph databases with global distribution and horizontal scale capabilities.

Prerequisites

An Azure account with an active subscription. Create one for free. Or try Azure Cosmos DB for free without an Azure subscription.
Java Development Kit (JDK) 8. Point your JAVA_HOME environment variable to the folder where the JDK is installed.
A Maven binary archive. On Ubuntu, run apt-get install maven to install Maven.
Git. On Ubuntu, run sudo apt-get install git to install Git.

Create a database account

Before you can create a document database, you need to create a Cassandra account with Azure Cosmos DB.

[!INCLUDE cosmos-db-create-dbaccount-cassandra]

Clone the sample application

Now let's switch to working with code. Let's clone a Cassandra app from GitHub, set the connection string, and run it. You'll see how easy it is to work with data programmatically.

Open a command prompt. Create a new folder named git-samples. Then, close the command prompt.
```
md "C:\git-samples"
```
Open a git terminal window, such as git bash, and use the cd command to change to the new folder to install the sample app.
```
cd "C:\git-samples"
```
Run the following command to clone the sample repository. This command creates a copy of the sample app on your computer.
```
git clone https://github.com/Azure-Samples/azure-cosmos-db-cassandra-java-getting-started-v4.git
```

Review the code

This step is optional. If you're interested to learn how the code creates the database resources, you can review the following snippets. Otherwise, you can skip ahead to Update your connection string. These snippets are all taken from the src/main/java/com/azure/cosmosdb/cassandra/util/CassandraUtils.java file.

The CqlSession connects to the Azure Cosmos DB Cassandra API and returns a session to access (Cluster object from v3 driver is now obsolete). Cassandra Host, Port, User name and password is set using the connection string page in the Azure portal.

    this.session = CqlSession.builder().withSslContext(sc)
            .addContactPoint(new InetSocketAddress(cassandraHost, cassandraPort)).withLocalDatacenter(region)
            .withAuthCredentials(cassandraUsername, cassandraPassword).build();

The following snippets are from the src/main/java/com/azure/cosmosdb/cassandra/repository/UserRepository.java file.

Drop the keyspace if it already exists from a previous run.

public void dropKeyspace() {
    String query = "DROP KEYSPACE IF EXISTS "+keyspace+"";
    session.execute(query);
    LOGGER.info("dropped keyspace '"+keyspace+"'");
}

A new keyspace is created.

public void createKeyspace() {
    String query = "CREATE KEYSPACE "+keyspace+" WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'datacenter1' : 1 }";
    session.execute(query);
    LOGGER.info("Created keyspace '"+keyspace+"'");
}

A new table is created.

 public void createTable() {
     String query = "CREATE TABLE "+keyspace+"."+table+" (user_id int PRIMARY KEY, user_name text, user_bcity text)";
     session.execute(query);
     LOGGER.info("Created table '"+table+"'");
 }

User entities are inserted using a prepared statement object.

public String prepareInsertStatement() {
    final String insertStatement = "INSERT INTO  "+keyspace+"."+table+" (user_id, user_name , user_bcity) VALUES (?,?,?)";
    return insertStatement;
}

public void insertUser(String preparedStatement, int id, String name, String city) {
    PreparedStatement prepared = session.prepare(preparedStatement);
    BoundStatement bound = prepared.bind(id, city, name).setIdempotent(true);
    session.execute(bound);
}

Query to get get all User information.

public void selectAllUsers() {
    final String query = "SELECT * FROM "+keyspace+"."+table+"";
    List<Row> rows = session.execute(query).all();

    for (Row row : rows) {
        LOGGER.info("Obtained row: {} | {} | {} ", row.getInt("user_id"), row.getString("user_name"), row.getString("user_bcity"));
    }
}

Query to get a single User information.

public void selectUser(int id) {
    final String query = "SELECT * FROM "+keyspace+"."+table+" where user_id = 3";
    Row row = session.execute(query).one();

    LOGGER.info("Obtained row: {} | {} | {} ", row.getInt("user_id"), row.getString("user_name"), row.getString("user_bcity"));
}

Update your connection string

Now go back to the Azure portal to get your connection string information and copy it into the app. The connection string details enable your app to communicate with your hosted database.

In your Azure Cosmos DB account in the Azure portal, select Connection String.

:::image type="content" source="./media/create-cassandra-java/copy-username-connection-string-azure-portal.png" alt-text="View and copy a username from the Azure portal, Connection String page":::
Use the :::image type="icon" source="./media/create-cassandra-java/copy-button-azure-portal.png"::: button on the right side of the screen to copy the CONTACT POINT value.
Open the config.properties file from the C:\git-samples\azure-cosmosdb-cassandra-java-getting-started\java-examples\src\main\resources folder.
Paste the CONTACT POINT value from the portal over <Cassandra endpoint host> on line 2.

Line 2 of config.properties should now look similar to

cassandra_host=cosmos-db-quickstart.cassandra.cosmosdb.azure.com
Go back to the portal and copy the USERNAME value. Past the USERNAME value from the portal over <cassandra endpoint username> on line 4.

Line 4 of config.properties should now look similar to

cassandra_username=cosmos-db-quickstart
Go back to the portal and copy the PASSWORD value. Paste the PASSWORD value from the portal over <cassandra endpoint password> on line 5.

Line 5 of config.properties should now look similar to

cassandra_password=2Ggkr662ifxz2Mg...==
On line 6, if you want to use a specific TLS/SSL certificate, then replace <SSL key store file location> with the location of the TLS/SSL certificate. If a value is not provided, the JDK certificate installed at <JAVA_HOME>/jre/lib/security/cacerts is used.
If you changed line 6 to use a specific TLS/SSL certificate, update line 7 to use the password for that certificate.
Note that you will need to add the default region (e.g. West US) for the contact point, e.g.

region=West US

This is because the v.4x driver only allows one local DC to be paired with the contact point. If you want to add a region other than the default (which is the region that was given when the Cosmos DB account was first created), you will need to use regional suffix when adding contact point, e.g. host-westus.cassandra.cosmos.azure.com.
Save the config.properties file.

Run the Java app

In the git terminal window, cd to the azure-cosmosdb-cassandra-java-getting-started-v4 folder.
```
cd "C:\git-samples\azure-cosmosdb-cassandra-java-getting-started-v4"
```
In the git terminal window, use the following command to generate the cosmosdb-cassandra-examples.jar file.
```
mvn clean install
```
In the git terminal window, run the following command to start the Java application.
```
java -cp target/cosmosdb-cassandra-examples.jar com.azure.cosmosdb.cassandra.examples.UserProfile
```
The terminal window displays notifications that the keyspace and table are created. It then selects and returns all users in the table and displays the output, and then selects a row by ID and displays the value.

Press Ctrl+C to stop execution of the program and close the console window.
In the Azure portal, open Data Explorer to query, modify, and work with this new data.

:::image type="content" source="./media/create-cassandra-java/view-data-explorer-java-app.png" alt-text="View the data in Data Explorer - Azure Cosmos DB":::

Review SLAs in the Azure portal

[!INCLUDE cosmosdb-tutorial-review-slas]

Clean up resources

[!INCLUDE cosmosdb-delete-resource-group]

Next steps

In this quickstart, you learned how to create an Azure Cosmos DB account with Cassandra API, and run a Cassandra Java app that creates a Cassandra database and container. You can now import additional data into your Azure Cosmos DB account.

[!div class="nextstepaction"] Import Cassandra data into Azure Cosmos DB

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create-cassandra-java-v4.md

create-cassandra-java-v4.md

Quickstart: Build a Java app to manage Azure Cosmos DB Cassandra API data (v4 Driver)

Prerequisites

Create a database account

Clone the sample application

Review the code

Update your connection string

Run the Java app

Review SLAs in the Azure portal

Clean up resources

Next steps

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create-cassandra-java-v4.md

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create-cassandra-java-v4.md

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Quickstart: Build a Java app to manage Azure Cosmos DB Cassandra API data (v4 Driver)

Prerequisites

Create a database account

Clone the sample application

Review the code

Update your connection string

Run the Java app

Review SLAs in the Azure portal

Clean up resources

Next steps