i have set environment variable for google credentials but i don't know what is the next step. Please help me to solve this error
The Application Default Credentials are not available. They are available if running in Google Compute Engine. Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS must be defined pointing to a file defining the credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.
at com.google.auth.oauth2.DefaultCredentialsProvider.getDefaultCredentials(DefaultCredentialsProvider.java:119)
at com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(GoogleCredentials.java:127)
at com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(GoogleCredentials.java:100)
at com.google.api.gax.core.GoogleCredentialsProvider.getCredentials(GoogleCredentialsProvider.java:53)
at com.google.api.gax.rpc.ClientContext.create(ClientContext.java:134)
at com.google.cloud.vision.v1.stub.GrpcImageAnnotatorStub.create(GrpcImageAnnotatorStub.java:61)
at com.google.cloud.vision.v1.stub.ImageAnnotatorStubSettings.createStub(ImageAnnotatorStubSettings.java:93)
at com.google.cloud.vision.v1.ImageAnnotatorClient.<init>(ImageAnnotatorClient.java:131)
at com.google.cloud.vision.v1.ImageAnnotatorClient.create(ImageAnnotatorClient.java:112)
at com.google.cloud.vision.v1.ImageAnnotatorClient.create(ImageAnnotatorClient.java:103)
at com.example.vision.QuickstartSample.main(QuickstartSample.java:42)