The InfluxDB 3 [`influxdb3-java` Java client library](https://github.com/InfluxCommunity/influxdb3-java) integrates
with Java application code to write and query data stored in {{% product-name %}}.

InfluxDB client libraries provide configurable batch writing of data to {{% product-name %}}.
Use client libraries to construct line protocol data, transform data from other formats
to line protocol, and batch write line protocol data to InfluxDB HTTP APIs.

InfluxDB 3 client libraries can query {{% product-name %}} using SQL or InfluxQL.
The `influxdb3-java` Java client library wraps the Apache Arrow `org.apache.arrow.flight.FlightClient`
in a convenient InfluxDB 3 interface for executing SQL and InfluxQL queries, requesting
server metadata, and retrieving data from {{% product-name %}} using the Flight protocol with gRPC.

- [Installation](#installation)
  - [Using Maven](#using-maven)
  - [Using Gradle](#using-gradle)
- [Importing the client](#importing-the-client)
- [API reference](#api-reference)
- [Classes](#classes)
- [InfluxDBClient interface](#influxdbclient-interface)
  - [Initialize with credential parameters](#initialize-with-credential-parameters)
  - [InfluxDBClient instance methods](#influxdbclient-instance-methods)
  - [InfluxDBClient.writePoint](#influxdbclientwritepoint)
  - [InfluxDBClient.query](#influxdbclientquery)
#### Example: write and query data

The following example shows how to use `influxdb3-java` to write and query data stored in {{% product-name %}}.

{{% code-placeholders "DATABASE_NAME | DATABASE_TOKEN" %}}

```java
package com.influxdata.demo;

import com.influxdb.v3.client.InfluxDBClient;
import com.influxdb.v3.client.Point;
import com.influxdb.v3.client.query.QueryOptions;
import com.influxdb.v3.client.query.QueryType;

import java.time.Instant;
import java.util.stream.Stream;

public class HelloInfluxDB {
  private static final String HOST_URL = "https://{{< influxdb/host >}}"; // your cluster URL
  private static final String DATABASE = "DATABASE_NAME"; // your InfluxDB database name 
  private static final char[] TOKEN = System.getenv("DATABASE_TOKEN"); // a local environment variable that stores your database token

  // Create a client instance that writes and queries data in your database.
  public static void main(String[] args) {
    // Instantiate the client with your InfluxDB credentials
    try (InfluxDBClient client = InfluxDBClient.getInstance(HOST_URL, TOKEN, DATABASE)) {
      writeData(client);
      queryData(client);
    }
    catch (Exception e) {
      System.err.println("An error occurred while connecting to InfluxDB!");
      e.printStackTrace();
    }
  }

  // Use the Point class to construct time series data.
  private static void writeData(InfluxDBClient client) {
    Point point = Point.measurement("temperature")
                       .setTag("location", "London")
                       .setField("value", 30.01)
                       .setTimestamp(Instant.now().minusSeconds(10));
    try {
      client.writePoint(point);
      System.out.println("Data is written to the database.");
    }
    catch (Exception e) {
      System.err.println("Failed to write data to the database.");
      e.printStackTrace();
    }
  }

  // Use SQL to query the most recent 10 measurements
  private static void queryData(InfluxDBClient client) {
    System.out.printf("--------------------------------------------------------%n");
    System.out.printf("| %-8s | %-8s | %-30s |%n", "location", "value", "time");
    System.out.printf("--------------------------------------------------------%n");

    String sql = "select time,location,value from temperature order by time desc limit 10";
    try (Stream<Object[]> stream = client.query(sql)) {
      stream.forEach(row -> System.out.printf("| %-8s | %-8s | %-30s |%n", row[1], row[2], row[0]));
    }
    catch (Exception e) {
      System.err.println("Failed to query data from the database.");
      e.printStackTrace();
    }
  }
}
```

{{% cite %}}Source: [suyashcjoshi/SimpleJavaInfluxDB](https://github.com/suyashcjoshi/SimpleJavaInfluxDB/) on GitHub{{% /cite %}}

{{% /code-placeholders %}}

Replace the following:

- {{% code-placeholder-key %}}`DATABASE_NAME`{{% /code-placeholder-key %}}:
  the name of your {{% product-name %}}
  [database](/influxdb3/version/admin/databases/) to read and write data to
- {{% code-placeholder-key %}}`DATABASE_TOKEN`{{% /code-placeholder-key %}}: a
  local environment variable that stores your
  [token](/influxdb3/version/admin/tokens/database/)--the token must have
  read and write permissions on the specified database.

### Run the example to write and query data

1. Build an executable JAR for the project--for example, using Maven:
   
   <!--pytest.mark.skip-->

   ```bash
   mvn package
   ```
   
2. In your terminal, run the `java` command to write and query data in your database:

   <!--pytest.mark.skip-->

   ```bash
   java \
   --add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED \
   -jar target/PROJECT_NAME.jar
   ```

   Include the following in your command:

   - [`--add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED`](https://arrow.apache.org/docs/java/install.html#id3): with Java version 9 or later and Apache Arrow version 16 or later, exposes JDK internals for Arrow.
   For more options, see the [Apache Arrow Java install documentation](https://arrow.apache.org/docs/java/install.html).
   - `-jar target/PROJECT_NAME.jar`: your `.jar` file to run.

The output is the newly written data from your {{< product-name >}} database.

## Installation

Include `com.influxdb.influxdb3-java` in your project dependencies.

{{< code-tabs-wrapper >}}
{{% code-tabs %}}
[Maven pom.xml](#)
[Gradle dependency script](#)
{{% /code-tabs %}}
{{% code-tab-content %}}
```xml
<dependency>
  <groupId>com.influxdb</groupId>
  <artifactId>influxdb3-java</artifactId>
  <version>RELEASE</version>
</dependency>
```
{{% /code-tab-content %}}
{{% code-tab-content %}}
<!--pytest.mark.skip-->
```groovy
dependencies {

   implementation group: 'com.influxdb', name: 'influxdb3-java', version: 'latest.release'

}
```
{{% /code-tab-content %}}
{{< /code-tabs-wrapper >}}

## Importing the client

The `influxdb3-java` client library package provides
`com.influxdb.v3.client` classes for constructing, writing, and querying data
stored in {{< product-name >}}.

## API reference

- [Interface InfluxDBClient](#interface-influxdbclient)
  - [Initialize with credential parameters](#initialize-with-credential-parameters)
  - [InfluxDBClient instance methods](#influxdbclient-instance-methods)
  - [InfluxDBClient.writePoint](#influxdbclientwritepoint)
  - [InfluxDBClient.query](#influxdbclientquery)
## InfluxDBClient interface

`InfluxDBClient` provides an interface for interacting with InfluxDB APIs for writing and querying data.

The `InfluxDBClient.getInstance` constructor initializes and returns a client instance with the following:

- A _write client_ configured for writing to the database.
- An Arrow _Flight client_ configured for querying the database.

To initialize a client, call `getInstance` and pass your credentials as one of
the following types:

- [parameters](#initialize-with-credential-parameters)
- a [`ClientConfig`](https://github.com/InfluxCommunity/influxdb3-java/blob/main/src/main/java/com/influxdb/v3/client/config/ClientConfig.java)
- a [database connection string](#initialize-using-a-database-connection-string)

### Initialize with credential parameters

{{% code-placeholders "host | database | token" %}}

```java
static InfluxDBClient getInstance(@Nonnull final String host,
                           @Nullable final char[] token,
                           @Nullable final String database)
```

{{% /code-placeholders %}}

- {{% code-placeholder-key %}}`host`{{% /code-placeholder-key %}} (string): The host URL of the InfluxDB instance.
- {{% code-placeholder-key %}}`database`{{% /code-placeholder-key %}} (string): The [database](/influxdb3/version/admin/databases/) to use for writing and querying.
- {{% code-placeholder-key %}}`token`{{% /code-placeholder-key %}} (char array): A [database token](/influxdb3/version/admin/tokens/database/) with read/write permissions.

#### Example: initialize with credential parameters

{{% code-placeholders "DATABASE_NAME | DATABASE_TOKEN" %}}

```java
package com.influxdata.demo;

import com.influxdb.v3.client.InfluxDBClient;
import com.influxdb.v3.client.Point;
import com.influxdb.v3.client.query.QueryOptions;
import com.influxdb.v3.client.query.QueryType;

import java.time.Instant;
import java.util.stream.Stream;

public class HelloInfluxDB {
  private static final String HOST_URL = "https://{{< influxdb/host >}}";
  private static final String DATABASE = "DATABASE_NAME";
  private static final char[] TOKEN = System.getenv("DATABASE_TOKEN");

  // Create a client instance, and then write and query data in InfluxDB.
  public static void main(String[] args) {
    try (InfluxDBClient client = InfluxDBClient.getInstance(HOST_URL, DATABASE_TOKEN, DATABASE)) {
      writeData(client);
      queryData(client);
    }
    catch (Exception e) {
      System.err.println("An error occurred while connecting to InfluxDB!");
      e.printStackTrace();
    }
  }
}
```

{{% /code-placeholders %}}

Replace the following:

- {{% code-placeholder-key %}}`DATABASE_NAME`{{% /code-placeholder-key %}}:
  your {{% product-name %}} [database](/influxdb3/version/admin/databases/)
- {{% code-placeholder-key %}}`DATABASE_TOKEN`{{% /code-placeholder-key %}}: a
  [database token](/influxdb3/version/admin/tokens/database/) that has
  the necessary permissions on the specified database.

#### Default tags

To include default [tags](/influxdb3/version/reference/glossary/#tag) in
all written data, pass a `Map` of tag keys and values.

```java
InfluxDBClient getInstance(@Nonnull final String host,
                                      @Nullable final char[] token,
                                      @Nullable final String database,
                                      @Nullable Map<String, String> defaultTags)
```

### Initialize using a database connection string

{{% code-placeholders "DATABASE_NAME | API_TOKEN" %}}

```java
"https://{{< influxdb/host >}}"
+ "?token=DATABASE_TOKEN&amp;database=DATABASE_NAME"
```

{{% /code-placeholders %}}

Replace the following:

- {{% code-placeholder-key %}}`DATABASE_NAME`{{% /code-placeholder-key %}}:
  your {{% product-name %}} [database](/influxdb3/version/admin/databases/)
- {{% code-placeholder-key %}}`DATABASE_TOKEN`{{% /code-placeholder-key %}}: a
  [database token](/influxdb3/version/admin/tokens/database/) that has
  the necessary permissions on the specified database.

### InfluxDBClient instance methods

#### InfluxDBClient.writePoint

To write points as line protocol to a database:

1. [Initialize the `client`](#initialize-with-credential-parameters)--your
   token must have write permission on the specified database.
2. Use the `com.influxdb.v3.client.Point` class to create time series data.
3. Call the `client.writePoint()` method to write points as line protocol in your
   database.

```java
  // Use the Point class to construct time series data.
  // Call client.writePoint to write the point in your database.
  private static void writeData(InfluxDBClient client) {
    Point point = Point.measurement("temperature")
                       .setTag("location", "London")
                       .setField("value", 30.01)
                       .setTimestamp(Instant.now().minusSeconds(10));
    try {
      client.writePoint(point);
      System.out.println("Data written to the database.");
    }
    catch (Exception e) {
      System.err.println("Failed to write data to the database.");
      e.printStackTrace();
    }
  }
```

#### InfluxDBClient.query

To query data and process the results:

1. [Initialize the `client`](#initialize-with-credential-parameters)--the
   token must have read permission on the database you want to query.
2. Call `client.query()` and provide your SQL query as a string.
3. Use the result stream's built-in iterator to process row data. 

```java
  // Query the latest 10 measurements using SQL
  private static void queryData(InfluxDBClient client) {
    System.out.printf("--------------------------------------------------------%n");
    System.out.printf("| %-8s | %-8s | %-30s |%n", "location", "value", "time");
    System.out.printf("--------------------------------------------------------%n");

    String sql = "select time,location,value from temperature order by time desc limit 10";
    try (Stream<Object[]> stream = client.query(sql)) {
      stream.forEach(row -> System.out.printf("| %-8s | %-8s | %-30s |%n", row[1], row[2], row[0]));
    }
    catch (Exception e) {
      System.err.println("Failed to query data from the database.");
      e.printStackTrace();
    }
  }
```

<a class="btn" href="https://github.com/InfluxCommunity/influxdb3-java/" target="\_blank">View the InfluxDB 3 Java client library</a>