# Tutorial: Using the AWS Health API with Java examples
<a name="code-sample-java"></a>

The following Java code examples demonstrate how to initialize an AWS Health client and retrieve information about events and entities.

## Step 1: Initialize credentials
<a name="step-1"></a>

Valid credentials are required to communicate with the AWS Health API. You can use the key pair of any IAM user associated with the AWS account.

Create and initialize an [AWSCredentials](https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/auth/AWSCredentials.html) instance:

```
AWSCredentials credentials = null;
try {
       credentials = new ProfileCredentialsProvider("default").getCredentials();
} catch (Exception e) {
throw new AmazonClientException(
   "Cannot load the credentials from the credential profiles file. "
   + "Please make sure that your credentials file is at the correct "
   + "location (/home/username/.aws/credentials), and is in valid format.", e);
}
```

## Step 2: Initialize an AWS Health API client
<a name="step-2"></a>

Use the initialized credentials object from the previous step to create an AWS Health client:

```
import com.amazonaws.services.health.AWSHealthClient;

AWSHealth awsHealthClient = new AWSHealthClient(credentials);
```

## Step 3: Use AWS Health API operations to get event information
<a name="step-3"></a>

**DescribeEvents**

```
import com.amazonaws.services.health.model.DescribeEventsRequest;
import com.amazonaws.services.health.model.DescribeEventsResult;
import com.amazonaws.services.health.model.Event;
import com.amazonaws.services.health.model.EventFilter;

DescribeEventsRequest request = new DescribeEventsRequest();

EventFilter filter = new EventFilter();
// Filter on any field from the supported AWS Health EventFilter model. 
// Here is an example for Region us-east-1 events from the EC2 service.
filter.setServices(singletonList("EC2"));
filter.setRegions(singletonList("us-east-1"));
request.setFilter(filter);

DescribeEventsResult response = awsHealthClient.describeEvents(request);
List<Event> resultEvents = response.getEvents();

Event currentEvent = null;
for (Event event : resultEvents) {
    // Display result event data; here is a subset.
    System.out.println(event.getArn());
    System.out.println(event.getService());
    System.out.println(event.getRegion());
    System.out.println(event.getAvailabilityZone());
    System.out.println(event.getStartTime());
    System.out.println(event.getEndTime());
 }
```

**DescribeEventAggregates**

```
import com.amazonaws.services.health.model.DescribeEventAggregatesRequest;
import com.amazonaws.services.health.model.DescribeEventAggregatesResult;
import com.amazonaws.services.health.model.EventAggregate;
import com.amazonaws.services.health.model.EventFilter;

DescribeEventAggregatesRequest request = new DescribeEventAggregatesRequest();
// set the aggregation field
request.setAggregateField("eventTypeCategory");

// filter more on result if needed
EventFilter filter = new EventFilter();
filter.setRegions(singleton("us-east-1"));
request.setFilter(filter);

DescribeEventAggregatesResult response = awsHealthClient.describeEventAggregates(request);

// print event count for each eventTypeCategory
for (EventAggregate aggregate: response.getEventAggregates()) {
    System.out.println("Event Category:" + aggregate.getAggregateValue());
    System.out.println("Event Count:" + aggregate.getCount());
 }
```

**DescribeEventDetails**

```
import com.amazonaws.services.health.model.DescribeEventDetailsRequest;
import com.amazonaws.services.health.model.DescribeEventDetailsResult;
import com.amazonaws.services.health.model.Event;
import com.amazonaws.services.health.model.EventDetails;


DescribeEventDetailsRequest describeEventDetailsRequest = new DescribeEventDetailsRequest();
// set event ARN and local value

describeEventDetailsRequest.setEventArns(singletonList("arn:aws:health:us-east-1::event/service/eventTypeCode/eventId"));
describeEventDetailsRequest.setLocale("en-US");
filter.setEventArns
DescribeEventDetailsResult describeEventDetailsResult = awsHealthClient.describeEventDetails(request);
EventDetails eventDetail = describeEventDetailsResult.getSuccessfulSet().get(0);

// check event-related fields
Event event = eventDetail.getEvent();
System.out.println(event.getService());
System.out.println(event.getRegion());
System.out.println(event.getAvailabilityZone());
System.out.println(event.getStartTime());
System.out.println(event.getEndTime());

// print out event description
System.out.println(eventDetail.getEventDescription().getLatestDescription());
```

**DescribeAffectedEntities**

```
import com.amazonaws.services.health.model.AffectedEntity;
import com.amazonaws.services.health.model.DateTimeRange;
import com.amazonaws.services.health.model.DescribeAffectedEntitiesRequest;
import com.amdescribeEventDetailsRequestazonaws.services.health.model.DescribeAffectedEntitiesResult;

DescribeAffectedEntitiesRequest request = new DescribeAffectedEntitiesRequest();
EntityFilter filter = new EntityFilter();

filter.setEventArns(singletonList("arn:aws:health:us-east-1::event/service/eventTypeCode/eventId"));

DescribeAffectedEntitiesResult response = awsHealthClient.describeAffectedEntities(request);

for (AffectedEntity affectedEntity: response.getEntities()) {
    System.out.println(affectedEntity.getEntityValue());
    System.out.println(affectedEntity.getAwsAccountId());
    System.out.println(affectedEntity.getEntityArn());
 }
```

**DescribeEntityAggregates**

```
import com.amazonaws.services.health.model.DescribeEntityAggregatesRequest;
import com.amazonaws.services.health.model.DescribeEntityAggregatesResult;
import com.amazonaws.services.health.model.EntityAggregate;

DescribeEntityAggregatesRequest request = new DescribeEntityAggregatesRequest();

request.setEventArns(singletonList("arn:aws:health:us-east-1::event/service/eventTypeCode/eventId"));

DescribeEntityAggregatesResult response = awsHealthClient.describeEntityAggregates(request);

for (EntityAggregate entityAggregate : response.getEntityAggregates()) {
    System.out.println(entityAggregate.getEventArn());
    System.out.println(entityAggregate.getCount());
 }
```