Exception Handling

/**
 * The base Azure service exception. This is the base class for all exceptions thrown by Azure SDK.
 */
class AzureException extends RuntimeException {
    /**
     * Constructs a new AzureException instance.
     */
    public AzureException();
    
    /**
     * Constructs a new AzureException instance with the specified detail message.
     * @param message The detail message (which is saved for later retrieval by the getMessage() method)
     */
    public AzureException(String message);
    
    /**
     * Constructs a new AzureException instance with the specified detail message and cause.
     * @param message The detail message (which is saved for later retrieval by the getMessage() method)
     * @param cause The cause (which is saved for later retrieval by the getCause() method)
     */
    public AzureException(String message, Throwable cause);
    
    /**
     * Constructs a new AzureException instance with the specified cause.
     * @param cause The cause (which is saved for later retrieval by the getCause() method)
     */
    public AzureException(Throwable cause);
    
    /**
     * Constructs a new AzureException instance.
     * @param message The detail message
     * @param cause The cause
     * @param enableSuppression Whether or not suppression is enabled or disabled
     * @param writableStackTrace Whether or not the stack trace should be writable
     */
    public AzureException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace);
}

/**
 * Exception thrown for an invalid response with custom error information.
 */
class HttpResponseException extends AzureException {
    /**
     * Initializes a new instance of the HttpResponseException class.
     * @param response The HTTP response associated with this exception
     */
    public HttpResponseException(HttpResponse response);
    
    /**
     * Initializes a new instance of the HttpResponseException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     */
    public HttpResponseException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the HttpResponseException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param value The deserialized response value
     */
    public HttpResponseException(String message, HttpResponse response, Object value);
    
    /**
     * Initializes a new instance of the HttpResponseException class.
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public HttpResponseException(HttpResponse response, Throwable cause);
    
    /**
     * Initializes a new instance of the HttpResponseException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception  
     * @param cause The Throwable which caused the creation of this exception
     */
    public HttpResponseException(String message, HttpResponse response, Throwable cause);
    
    /**
     * Initializes a new instance of the HttpResponseException class.
     * @param message The exception message
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     * @param enableSuppression Whether suppression is enabled or disabled
     * @param writableStackTrace Whether the stack trace should be writable
     */
    public HttpResponseException(String message, HttpResponse response, Throwable cause, boolean enableSuppression, boolean writableStackTrace);
    
    /**
     * Gets the HTTP response that caused the exception.
     * @return The HTTP response that caused the exception
     */
    public HttpResponse getResponse();
    
    /**
     * Gets the deserialized HTTP response value.
     * @return The deserialized HTTP response value
     */
    public Object getValue();
}

/**
 * Exception thrown when authentication fails.
 */
class ClientAuthenticationException extends HttpResponseException {
    /**
     * Initializes a new instance of the ClientAuthenticationException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     */
    public ClientAuthenticationException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the ClientAuthenticationException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param value The deserialized response value
     */
    public ClientAuthenticationException(String message, HttpResponse response, Object value);
    
    /**
     * Initializes a new instance of the ClientAuthenticationException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public ClientAuthenticationException(String message, HttpResponse response, Throwable cause);
}

/**
 * Exception thrown when a resource already exists.
 */
class ResourceExistsException extends HttpResponseException {
    /**
     * Initializes a new instance of the ResourceExistsException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     */
    public ResourceExistsException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the ResourceExistsException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param value The deserialized response value
     */
    public ResourceExistsException(String message, HttpResponse response, Object value);
    
    /**
     * Initializes a new instance of the ResourceExistsException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public ResourceExistsException(String message, HttpResponse response, Throwable cause);
}

/**
 * Exception thrown when a resource is not found.
 */
class ResourceNotFoundException extends HttpResponseException {
    /**
     * Initializes a new instance of the ResourceNotFoundException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     */
    public ResourceNotFoundException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the ResourceNotFoundException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param value The deserialized response value
     */
    public ResourceNotFoundException(String message, HttpResponse response, Object value);
    
    /**
     * Initializes a new instance of the ResourceNotFoundException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public ResourceNotFoundException(String message, HttpResponse response, Throwable cause);
}

/**
 * Exception thrown when a resource has been modified.
 */
class ResourceModifiedException extends HttpResponseException {
    /**
     * Initializes a new instance of the ResourceModifiedException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     */
    public ResourceModifiedException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the ResourceModifiedException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param value The deserialized response value
     */
    public ResourceModifiedException(String message, HttpResponse response, Object value);
    
    /**
     * Initializes a new instance of the ResourceModifiedException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public ResourceModifiedException(String message, HttpResponse response, Throwable cause);
}

/**
 * Exception thrown when an HTTP request fails.
 */
class HttpRequestException extends AzureException {
    /**
     * Initializes a new instance of the HttpRequestException class.
     * @param message The exception message
     */
    public HttpRequestException(String message);
    
    /**
     * Initializes a new instance of the HttpRequestException class.
     * @param message The exception message
     * @param cause The Throwable which caused the creation of this exception
     */
    public HttpRequestException(String message, Throwable cause);
    
    /**
     * Initializes a new instance of the HttpRequestException class.
     * @param cause The Throwable which caused the creation of this exception
     */
    public HttpRequestException(Throwable cause);
}

/**
 * Exception thrown when decoding/deserializing fails.
 */
class DecodeException extends AzureException {
    /**
     * Initializes a new instance of the DecodeException class.
     * @param message The exception message
     */
    public DecodeException(String message);
    
    /**
     * Initializes a new instance of the DecodeException class.
     * @param message The exception message
     * @param cause The Throwable which caused the creation of this exception
     */
    public DecodeException(String message, Throwable cause);
    
    /**
     * Initializes a new instance of the DecodeException class.
     * @param cause The Throwable which caused the creation of this exception
     */
    public DecodeException(Throwable cause);
}

/**
 * Exception thrown when the response body length doesn't match the expected length.
 */
class UnexpectedLengthException extends HttpResponseException {
    /**
     * Initializes a new instance of the UnexpectedLengthException class.
     * @param message The exception message
     * @param response The HTTP response associated with this exception
     */
    public UnexpectedLengthException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the UnexpectedLengthException class.
     * @param message The exception message
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public UnexpectedLengthException(String message, HttpResponse response, Throwable cause);
}

/**
 * Exception thrown when too many redirects occur.
 */
class TooManyRedirectsException extends HttpResponseException {
    /**
     * Initializes a new instance of the TooManyRedirectsException class.
     * @param message The exception message
     * @param response The HTTP response associated with this exception
     */
    public TooManyRedirectsException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the TooManyRedirectsException class.
     * @param message The exception message
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public TooManyRedirectsException(String message, HttpResponse response, Throwable cause);
}

/**
 * Exception thrown for service response errors.
 */
class ServiceResponseException extends HttpResponseException {
    /**
     * Initializes a new instance of the ServiceResponseException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     */
    public ServiceResponseException(String message, HttpResponse response);
    
    /**
     * Initializes a new instance of the ServiceResponseException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param value The deserialized response value
     */
    public ServiceResponseException(String message, HttpResponse response, Object value);
    
    /**
     * Initializes a new instance of the ServiceResponseException class.
     * @param message The exception message or the response content if a message is not available
     * @param response The HTTP response associated with this exception
     * @param cause The Throwable which caused the creation of this exception
     */
    public ServiceResponseException(String message, HttpResponse response, Throwable cause);
}

import com.azure.core.exception.*;
import com.azure.core.http.HttpResponse;

public class ServiceClient {
    
    public void handleBasicExceptions() {
        try {
            // Service operation that may fail
            performServiceOperation();
        } catch (ClientAuthenticationException e) {
            // Handle authentication failures
            System.err.println("Authentication failed: " + e.getMessage());
            System.err.println("Status code: " + e.getResponse().getStatusCode());
            
            // Re-authenticate or prompt for new credentials
            handleAuthenticationFailure(e);
            
        } catch (ResourceNotFoundException e) {
            // Handle missing resources
            System.err.println("Resource not found: " + e.getMessage());
            
            // Create the resource or handle gracefully
            handleMissingResource(e);
            
        } catch (ResourceExistsException e) {
            // Handle resource conflicts
            System.err.println("Resource already exists: " + e.getMessage());
            
            // Use existing resource or update it
            handleResourceConflict(e);
            
        } catch (HttpResponseException e) {
            // Handle other HTTP errors
            System.err.println("HTTP error: " + e.getMessage());
            System.err.println("Status code: " + e.getResponse().getStatusCode());
            
            // Log response details and handle appropriately
            handleGeneralHttpError(e);
            
        } catch (AzureException e) {
            // Handle all other Azure SDK exceptions
            System.err.println("Azure SDK error: " + e.getMessage());
            handleGeneralAzureError(e);
        }
    }
    
    private void performServiceOperation() {
        // Implementation
    }
    
    private void handleAuthenticationFailure(ClientAuthenticationException e) {
        // Implementation
    }
    
    private void handleMissingResource(ResourceNotFoundException e) {
        // Implementation
    }
    
    private void handleResourceConflict(ResourceExistsException e) {
        // Implementation
    }
    
    private void handleGeneralHttpError(HttpResponseException e) {
        // Implementation
    }
    
    private void handleGeneralAzureError(AzureException e) {
        // Implementation
    }
}

import com.azure.core.exception.*;
import reactor.core.publisher.Mono;
import reactor.util.retry.Retry;
import java.time.Duration;

public class ReactiveServiceClient {
    
    public Mono<String> getResourceWithRetry(String resourceId) {
        return performAsyncOperation(resourceId)
            .onErrorResume(ClientAuthenticationException.class, this::handleAuthError)
            .onErrorResume(ResourceNotFoundException.class, this::handleNotFound)
            .onErrorResume(TooManyRedirectsException.class, this::handleRedirectError)
            .retryWhen(Retry.backoff(3, Duration.ofSeconds(1))
                .filter(this::isRetryableException)
                .onRetryExhaustedThrow((retryBackoffSpec, retrySignal) -> {
                    return new RuntimeException("Retry exhausted after " + retrySignal.totalRetries() + " attempts");
                }));
    }
    
    private Mono<String> performAsyncOperation(String resourceId) {
        // Implementation
        return Mono.just("result");
    }
    
    private Mono<String> handleAuthError(ClientAuthenticationException e) {
        System.err.println("Authentication failed, attempting to refresh token");
        return refreshTokenAndRetry(e);
    }
    
    private Mono<String> handleNotFound(ResourceNotFoundException e) {
        System.err.println("Resource not found, creating default resource");
        return createDefaultResource();
    }
    
    private Mono<String> handleRedirectError(TooManyRedirectsException e) {
        System.err.println("Too many redirects, aborting operation");
        return Mono.error(new RuntimeException("Operation failed due to excessive redirects", e));
    }
    
    private boolean isRetryableException(Throwable e) {
        if (e instanceof HttpResponseException) {
            int statusCode = ((HttpResponseException) e).getResponse().getStatusCode();
            // Retry on server errors (5xx) and rate limiting (429)
            return statusCode >= 500 || statusCode == 429;
        }
        return e instanceof HttpRequestException || e instanceof DecodeException;
    }
    
    private Mono<String> refreshTokenAndRetry(ClientAuthenticationException e) {
        // Implementation to refresh authentication and retry
        return Mono.just("refreshed-result");
    }
    
    private Mono<String> createDefaultResource() {
        // Implementation to create a default resource
        return Mono.just("default-resource");
    }
}

import com.azure.core.exception.*;
import com.azure.core.http.HttpHeaders;

public class ExceptionAnalyzer {
    
    public void analyzeException(Exception e) {
        if (e instanceof HttpResponseException) {
            analyzeHttpResponseException((HttpResponseException) e);
        } else if (e instanceof AzureException) {
            analyzeAzureException((AzureException) e);
        } else {
            analyzeGeneralException(e);
        }
    }
    
    private void analyzeHttpResponseException(HttpResponseException e) {
        System.out.println("HTTP Response Exception Analysis:");
        System.out.println("Message: " + e.getMessage());
        
        HttpResponse response = e.getResponse();
        if (response != null) {
            System.out.println("Status Code: " + response.getStatusCode());
            System.out.println("Reason Phrase: " + response.getReasonPhrase());
            
            // Analyze headers
            HttpHeaders headers = response.getHeaders();
            System.out.println("Headers:");
            headers.forEach((name, value) -> 
                System.out.println("  " + name + ": " + value));
            
            // Get response body if available
            try {
                String body = response.getBodyAsString().block();
                System.out.println("Response Body: " + body);
            } catch (Exception bodyException) {
                System.out.println("Could not read response body: " + bodyException.getMessage());
            }
        }
        
        // Check for deserialized response value
        Object value = e.getValue();
        if (value != null) {
            System.out.println("Deserialized Value Type: " + value.getClass().getSimpleName());
            System.out.println("Deserialized Value: " + value.toString());
        }
        
        // Determine exception type and provide specific guidance
        if (e instanceof ClientAuthenticationException) {
            System.out.println("Recommendation: Check credentials and token expiration");
        } else if (e instanceof ResourceNotFoundException) {
            System.out.println("Recommendation: Verify resource exists and path is correct");
        } else if (e instanceof ResourceExistsException) {
            System.out.println("Recommendation: Use PUT for updates or check if resource should be replaced");
        } else if (e instanceof TooManyRedirectsException) {
            System.out.println("Recommendation: Check for redirect loops or increase redirect limit");
        }
    }
    
    private void analyzeAzureException(AzureException e) {
        System.out.println("Azure Exception Analysis:");
        System.out.println("Message: " + e.getMessage());
        System.out.println("Type: " + e.getClass().getSimpleName());
        
        if (e.getCause() != null) {
            System.out.println("Root Cause: " + e.getCause().getMessage());
            System.out.println("Root Cause Type: " + e.getCause().getClass().getSimpleName());
        }
        
        // Print stack trace for debugging
        e.printStackTrace();
    }
    
    private void analyzeGeneralException(Exception e) {
        System.out.println("General Exception Analysis:");
        System.out.println("Message: " + e.getMessage());
        System.out.println("Type: " + e.getClass().getSimpleName());
        e.printStackTrace();
    }
}

import com.azure.core.exception.*;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;

public class CustomExceptionHandler {
    private final Map<Class<? extends Exception>, Function<Exception, String>> handlers = new ConcurrentHashMap<>();
    
    public CustomExceptionHandler() {
        setupDefaultHandlers();
    }
    
    private void setupDefaultHandlers() {
        // Register specific handlers for different exception types
        handlers.put(ClientAuthenticationException.class, this::handleAuthenticationException);
        handlers.put(ResourceNotFoundException.class, this::handleResourceNotFoundException);
        handlers.put(ResourceExistsException.class, this::handleResourceExistsException);
        handlers.put(ResourceModifiedException.class, this::handleResourceModifiedException);
        handlers.put(TooManyRedirectsException.class, this::handleTooManyRedirectsException);
        handlers.put(UnexpectedLengthException.class, this::handleUnexpectedLengthException);
        handlers.put(DecodeException.class, this::handleDecodeException);
        handlers.put(HttpRequestException.class, this::handleHttpRequestException);
        handlers.put(HttpResponseException.class, this::handleHttpResponseException);
        handlers.put(AzureException.class, this::handleAzureException);
    }
    
    public String handleException(Exception e) {
        Function<Exception, String> handler = findHandler(e.getClass());
        return handler != null ? handler.apply(e) : handleUnknownException(e);
    }
    
    private Function<Exception, String> findHandler(Class<? extends Exception> exceptionClass) {
        // Try exact match first
        Function<Exception, String> handler = handlers.get(exceptionClass);
        if (handler != null) {
            return handler;
        }
        
        // Try to find handler for parent classes
        for (Map.Entry<Class<? extends Exception>, Function<Exception, String>> entry : handlers.entrySet()) {
            if (entry.getKey().isAssignableFrom(exceptionClass)) {
                return entry.getValue();
            }
        }
        
        return null;
    }
    
    private String handleAuthenticationException(Exception e) {
        ClientAuthenticationException authEx = (ClientAuthenticationException) e;
        return String.format("Authentication failed (Status: %d). Please check your credentials and ensure they have not expired.",
            authEx.getResponse().getStatusCode());
    }
    
    private String handleResourceNotFoundException(Exception e) {
        ResourceNotFoundException notFoundEx = (ResourceNotFoundException) e;
        return String.format("The requested resource was not found (Status: %d). Please verify the resource identifier and try again.",
            notFoundEx.getResponse().getStatusCode());
    }
    
    private String handleResourceExistsException(Exception e) {
        ResourceExistsException existsEx = (ResourceExistsException) e;
        return String.format("The resource already exists (Status: %d). Use PUT to update or check if the operation is idempotent.",
            existsEx.getResponse().getStatusCode());
    }
    
    private String handleResourceModifiedException(Exception e) {
        ResourceModifiedException modifiedEx = (ResourceModifiedException) e;
        return String.format("The resource has been modified (Status: %d). Please refresh and retry with updated information.",
            modifiedEx.getResponse().getStatusCode());
    }
    
    private String handleTooManyRedirectsException(Exception e) {
        return "Too many redirects encountered. This may indicate a redirect loop or misconfigured service endpoint.";
    }
    
    private String handleUnexpectedLengthException(Exception e) {
        return "Response body length did not match expected length. The data may be corrupted or truncated.";
    }
    
    private String handleDecodeException(Exception e) {
        return "Failed to decode response data. The response format may be invalid or unsupported.";
    }
    
    private String handleHttpRequestException(Exception e) {
        return "HTTP request failed. Please check network connectivity and service availability.";
    }
    
    private String handleHttpResponseException(Exception e) {
        HttpResponseException httpEx = (HttpResponseException) e;
        int statusCode = httpEx.getResponse().getStatusCode();
        
        if (statusCode >= 400 && statusCode < 500) {
            return String.format("Client error (Status: %d). Please check the request parameters and authentication.", statusCode);
        } else if (statusCode >= 500) {
            return String.format("Server error (Status: %d). The service may be temporarily unavailable.", statusCode);
        } else {
            return String.format("Unexpected HTTP response (Status: %d).", statusCode);
        }
    }
    
    private String handleAzureException(Exception e) {
        return String.format("Azure SDK error: %s. Please check the operation parameters and try again.", e.getMessage());
    }
    
    private String handleUnknownException(Exception e) {
        return String.format("An unexpected error occurred: %s. Please contact support if the issue persists.", e.getMessage());
    }
    
    // Allow users to register custom handlers
    public <T extends Exception> void registerHandler(Class<T> exceptionClass, Function<Exception, String> handler) {
        handlers.put(exceptionClass, handler);
    }
}

import com.azure.core.exception.*;
import com.azure.core.util.logging.ClientLogger;
import java.time.Instant;
import java.util.HashMap;
import java.util.Map;

public class ExceptionReporter {
    private static final ClientLogger LOGGER = new ClientLogger(ExceptionReporter.class);
    
    public void reportException(Exception e, String operationName, String clientName) {
        Map<String, Object> telemetryData = new HashMap<>();
        telemetryData.put("timestamp", Instant.now().toString());
        telemetryData.put("operation", operationName);
        telemetryData.put("client", clientName);
        telemetryData.put("exceptionType", e.getClass().getSimpleName());
        telemetryData.put("message", e.getMessage());
        
        if (e instanceof HttpResponseException) {
            HttpResponseException httpEx = (HttpResponseException) e;
            HttpResponse response = httpEx.getResponse();
            
            telemetryData.put("statusCode", response.getStatusCode());
            telemetryData.put("reasonPhrase", response.getReasonPhrase());
            
            // Add request ID if available
            String requestId = response.getHeaderValue("x-ms-request-id");
            if (requestId != null) {
                telemetryData.put("requestId", requestId);
            }
            
            // Add correlation ID if available
            String correlationId = response.getHeaderValue("x-ms-correlation-request-id");
            if (correlationId != null) {
                telemetryData.put("correlationId", correlationId);
            }
        }
        
        // Log the exception with telemetry data
        LOGGER.error("Operation failed: {}", telemetryData, e);
        
        // Send to telemetry system (implementation-specific)
        sendToTelemetrySystem(telemetryData);
    }
    
    private void sendToTelemetrySystem(Map<String, Object> telemetryData) {
        // Implementation would send data to Application Insights, custom telemetry system, etc.
        System.out.println("Telemetry: " + telemetryData);
    }
}