package ca.intelliware.ihtsdo.mlds.config.metrics; import java.util.LinkedHashMap; import java.util.Map; import org.apache.commons.lang.exception.ExceptionUtils; import org.springframework.boot.actuate.health.HealthIndicator; /** * A health indicator check for a component of your application */ public abstract class HealthCheckIndicator implements HealthIndicator<Map<String, HealthCheckIndicator.Result>> { private static final Result HEALTHY = new Result(true, null, null); /** * @return the name of the indicator */ protected abstract String getHealthCheckIndicatorName(); /** * Perform a check of the application component. * * @return if the component is healthy, a healthy Result; otherwise, an unhealthy Result * with a descriptive error message or/and exception * @throws Exception if there is an unhandled error during the health check; this will result in * a failed health check */ protected abstract Result check() throws Exception; @Override final public Map<String, Result> health() { Map<String, Result> results = new LinkedHashMap<>(); try { results.put(getHealthCheckIndicatorName(), check()); } catch (Exception e) { results.put(getHealthCheckIndicatorName(), unhealthy(e)); } return results; } /** * @return a healthy Result with no additional message */ public static Result healthy() { return HEALTHY; } /** * @param message an informative message * @return a healthy Result with an additional message */ public static Result healthy(String message) { return new Result(true, message, null); } /** * @param message an informative message describing how the health check indicator failed * @return an unhealthy Result with the given message */ public static Result unhealthy(String message) { return new Result(false, message, null); } /** * @param error an exception thrown during the health check * @return an unhealthy Result with the given error */ public static Result unhealthy(Throwable error) { return new Result(false, error.getMessage(), error); } /** * @param message an informative message describing how the health check indicator failed * @param error an exception thrown during the health check * @return an unhealthy Result with the given error */ public static Result unhealthy(String message, Throwable error) { return new Result(false, message, error); } /** * The result of a HealthCheckIndicator */ public static class Result { private boolean healthy; private String message; private Throwable exception; public Result(boolean healthy, String message) { this.healthy = healthy; this.message = message; } public Result(boolean healthy, String message, Throwable exception) { this.healthy = healthy; this.message = message; this.exception = exception; } public boolean isHealthy() { return healthy; } public String getMessage() { return message; } public String getException() { return ExceptionUtils.getFullStackTrace(exception); } } }