Spring Resttemplate exception handling

You want to create a class that implements ResponseErrorHandler and then use an instance of it to set the error handling of your rest template:

public class MyErrorHandler implements ResponseErrorHandler {
  @Override
  public void handleError(ClientHttpResponse response) throws IOException {
    // your error handling here
  }

  @Override
  public boolean hasError(ClientHttpResponse response) throws IOException {
     ...
  }
}

[...]

public static void main(String args[]) {
  RestTemplate restTemplate = new RestTemplate();
  restTemplate.setErrorHandler(new MyErrorHandler());
}

Also, Spring has the class DefaultResponseErrorHandler, which you can extend instead of implementing the interface, in case you only want to override the handleError method.

public class MyErrorHandler extends DefaultResponseErrorHandler {
  @Override
  public void handleError(ClientHttpResponse response) throws IOException {
    // your error handling here
  }
}

Take a look at its source code to have an idea of how Spring handles HTTP errors.