> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metlo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Java

Currently Metlo's Java Agent supports 1 framework:

* Spring (and by extension Spring Boot)

Its available for download from
[maven central](https://repo1.maven.org/maven2/com/metlo/spring/)

### Installation

You can add Metlo via either Maven or Gradle:

Gradle:

```Gradle Gradle theme={null}
dependencies {
    ...
    implementation com.metlo.spring:0.3
}
```

Maven:

```XML XML theme={null}
<dependencies>
    ....
    <dependency>
        <groupId>com.metlo</groupId>
        <artifactId>spring</artifactId>
        <version>0.3</version>
        <scope>compile</scope>
    </dependency>
</dependencies>
```

### Usage

Metlo for Spring/Boot provides a lightweight filter for spring based
applications and can be included as any other filter would. The filter needs to
be provided with the METLO collector url, and the METLO API Key as parameters.

#### Example

```java Java theme={null}
package com.example.demo;

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

// Metlo imported here import com.metlo.spring.Metlo;

@Configuration public class FilterConfig {

    @Bean
    public FilterRegistrationBean<Metlo> loggingFilter() {
        FilterRegistrationBean<Metlo> registrationBean = new FilterRegistrationBean<>();

        // Metlo registered as a filter here
        registrationBean.setFilter(new Metlo("http://<YOUR_METLO_HOST>:8081", "<YOUR_METLO_API_KEY>"));
        registrationBean.setOrder(2);
        return registrationBean;
    }

}
```

#### Configuration

#### Rate Limiting

Metlo rate limits itself to 10 requests/s by default. In case the system has the
capacity to handle more and/or a larger number of traces needs to be reported
for some reason, that can be customised in the constructor with the signature:

```java Java theme={null}
public Metlo(String host, String api_key, Integer rps)
```