AWS/Java:如何从AWS Java API获取EC2实例

我试图通过aws java api以编程方式列出我的ec2实例.

public static void main(String[] args) {
    AWSCredentials awsCredentials = new BasicAWSCredentials(awsAccessKey, awsSecretKey);
    AmazonEC2AsyncClient amazonEC2AsyncClient = new AmazonEC2AsyncClient(awsCredentials);
    DescribeAvailabilityZonesRequest describeAvailabilityZonesRequest = new DescribeAvailabilityZonesRequest();
    Future describeAvailabilityZonesResultFuture = amazonEC2AsyncClient.describeAvailabilityZonesAsync(describeAvailabilityZonesRequest);
    try {
        DescribeAvailabilityZonesResult describeAvailabilityZonesResult = describeAvailabilityZonesResultFuture.get();
        System.out.println(describeAvailabilityZonesResult);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

这打印如下:

{AvailabilityZones: [
    {ZoneName: us-east-1a,State: available,RegionName: us-east-1,Messages: []}, 
    {ZoneName: us-east-1b,State: available,RegionName: us-east-1,Messages: []}, 
    {ZoneName: us-east-1c,State: available,RegionName: us-east-1,Messages: []}]}

但是,我知道我在us-west-2中有例子.当我将其添加到我的api查询中时

describeAvailabilityZonesRequest.withZoneNames("us-west-2");

我收到这个错误

java.util.concurrent.ExecutionException: com.amazonaws.AmazonServiceException: Status Code: 400, AWS Service: AmazonEC2, AWS Request ID: 38956486-2686-4466-b9e0-45ef12395676, AWS Error Code: InvalidParameterValue, 
AWS Error Message: Invalid availability zone: [us-west-2]
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:188)
    at com.pledgeling.platform.system.SystemAdmin.main(SystemAdmin.java:25)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: com.amazonaws.AmazonServiceException: Status Code: 400, AWS Service: AmazonEC2, AWS Request ID: 38956486-2686-4466-b9e0-45ef12395676, AWS Error Code: InvalidParameterValue, AWS Error Message: Invalid availability zone: [us-west-2]
    at com.amazonaws.http.AmazonHttpClient.handleErrorResponse(AmazonHttpClient.java:767)
    at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:414)
    at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:228)
    at com.amazonaws.services.ec2.AmazonEC2Client.invoke(AmazonEC2Client.java:7918)

我该怎么做才能解决这个问题？为什么我的us-west实例没有出现？