This document discusses best practices for logging and exception handling in Java. It recommends:
1. Logging method entries, exits, and root cause messages of handled exceptions.
2. Avoiding redundant intermediate logging and only logging at the exception origin.
3. Handling exceptions close to their origin by throwing a new exception relevant to that layer while maintaining the cause.
4. Logging exceptions only once close to the origin to avoid confusion from duplicated stack traces.
5. Not catching the base Exception class to avoid accidentally swallowing unchecked exceptions.
in this tutorial we will discuss about
exception handling in C#
Exception class
creating user-defined exception
throw keyword
finally keyword
with examples'
in this tutorial we will discuss about
exception handling in C#
Exception class
creating user-defined exception
throw keyword
finally keyword
with examples'
Object-oriented programming Undergraduate Course Presentations
java.io streams and files in Java
University of Vale do Itajaí
Univali
Incremental Tecnologia
English version
This talk introduces Spring's REST stack - Spring MVC, Spring HATEOAS, Spring Data REST, Spring Security OAuth and Spring Social - while refining an API to move higher up the Richardson maturity model
The presentation given at MSBTE sponsored content updating program on 'Advanced Java Programming' for Diploma Engineering teachers of Maharashtra. Venue: Guru Gobind Singh Polytechnic, Nashik
Date: 22/12/2010
Session: Java Network Programming
oops concept in java | object oriented programming in javaCPD INDIA
object oriented programming is a key concept for the development of application in windows as well as web based application environment. oops concept maps real world through its concept of classes, objects, inheritance, polymorphism which help in making a robust application.
Deadlocks-An Unconditional Waiting Situation in Operating System. We must make sure of This concept well before understanding deep in to Operating System. This PPT will understands you to get how the deadlocks Occur and how can we Detect, avoid and Prevent the deadlocks in Operating Systems.
Message and Stream Oriented CommunicationDilum Bandara
Message and Stream Oriented Communication in distributed systems. Persistent vs. Transient Communication. Event queues, Pub/sub networks, MPI, Stream-based communication, Multicast communication
Java Exception Handling, Assertions and LoggingRiccardo Cardin
This presentation introduces the java exception handling mechanisms. In detail, the main focus of the slides is to show how the language implements its exception handling polices, such as:
- Checked and uncheked exception
- Try / catch blocks
- Assertions
- Logging
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
Object-oriented programming Undergraduate Course Presentations
java.io streams and files in Java
University of Vale do Itajaí
Univali
Incremental Tecnologia
English version
This talk introduces Spring's REST stack - Spring MVC, Spring HATEOAS, Spring Data REST, Spring Security OAuth and Spring Social - while refining an API to move higher up the Richardson maturity model
The presentation given at MSBTE sponsored content updating program on 'Advanced Java Programming' for Diploma Engineering teachers of Maharashtra. Venue: Guru Gobind Singh Polytechnic, Nashik
Date: 22/12/2010
Session: Java Network Programming
oops concept in java | object oriented programming in javaCPD INDIA
object oriented programming is a key concept for the development of application in windows as well as web based application environment. oops concept maps real world through its concept of classes, objects, inheritance, polymorphism which help in making a robust application.
Deadlocks-An Unconditional Waiting Situation in Operating System. We must make sure of This concept well before understanding deep in to Operating System. This PPT will understands you to get how the deadlocks Occur and how can we Detect, avoid and Prevent the deadlocks in Operating Systems.
Message and Stream Oriented CommunicationDilum Bandara
Message and Stream Oriented Communication in distributed systems. Persistent vs. Transient Communication. Event queues, Pub/sub networks, MPI, Stream-based communication, Multicast communication
Java Exception Handling, Assertions and LoggingRiccardo Cardin
This presentation introduces the java exception handling mechanisms. In detail, the main focus of the slides is to show how the language implements its exception handling polices, such as:
- Checked and uncheked exception
- Try / catch blocks
- Assertions
- Logging
The presentation is took from the Java course I run in the bachelor-level informatics curriculum at the University of Padova.
This is the material that I prepared for gathering best practices in exception handling that we aim to follow. I used the content stated in the references section.
JAVA EXCEPTION HANDLING
N.V.Raja Sekhar Reddy
www.technolamp.co.in
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Best Coding Practices For Android Application DevelopmentKetan Raval
Learn how to make coding at the time of android application development. Best practices for coding for android app development. Points to take care at the time of development application.
Exceptions are a powerful mechanism for centralized processing of errors and exceptional situations. This mechanism replaces the procedure-oriented method of error handling in which each function returns a code indicating an error or a successful execution.
This presentation explains a team work model that can be applied to development projects to facilitate smooth functioning of the project even during sudden non-availability of a developer or in cases where a developer departs from the team.
This presentation explains how to play some team building activities that are important to the effective management and growth of teams and their objectives.
This is a presentation about XStream, the lightweight and easy-to-use open source Java™ library, used for serializing java objects into XML and de-serializing XML back into java objects.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Welocme to ViralQR, your best QR code generator.ViralQR
Welcome to ViralQR, your best QR code generator available on the market!
At ViralQR, we design static and dynamic QR codes. Our mission is to make business operations easier and customer engagement more powerful through the use of QR technology. Be it a small-scale business or a huge enterprise, our easy-to-use platform provides multiple choices that can be tailored according to your company's branding and marketing strategies.
Our Vision
We are here to make the process of creating QR codes easy and smooth, thus enhancing customer interaction and making business more fluid. We very strongly believe in the ability of QR codes to change the world for businesses in their interaction with customers and are set on making that technology accessible and usable far and wide.
Our Achievements
Ever since its inception, we have successfully served many clients by offering QR codes in their marketing, service delivery, and collection of feedback across various industries. Our platform has been recognized for its ease of use and amazing features, which helped a business to make QR codes.
Our Services
At ViralQR, here is a comprehensive suite of services that caters to your very needs:
Static QR Codes: Create free static QR codes. These QR codes are able to store significant information such as URLs, vCards, plain text, emails and SMS, Wi-Fi credentials, and Bitcoin addresses.
Dynamic QR codes: These also have all the advanced features but are subscription-based. They can directly link to PDF files, images, micro-landing pages, social accounts, review forms, business pages, and applications. In addition, they can be branded with CTAs, frames, patterns, colors, and logos to enhance your branding.
Pricing and Packages
Additionally, there is a 14-day free offer to ViralQR, which is an exceptional opportunity for new users to take a feel of this platform. One can easily subscribe from there and experience the full dynamic of using QR codes. The subscription plans are not only meant for business; they are priced very flexibly so that literally every business could afford to benefit from our service.
Why choose us?
ViralQR will provide services for marketing, advertising, catering, retail, and the like. The QR codes can be posted on fliers, packaging, merchandise, and banners, as well as to substitute for cash and cards in a restaurant or coffee shop. With QR codes integrated into your business, improve customer engagement and streamline operations.
Comprehensive Analytics
Subscribers of ViralQR receive detailed analytics and tracking tools in light of having a view of the core values of QR code performance. Our analytics dashboard shows aggregate views and unique views, as well as detailed information about each impression, including time, device, browser, and estimated location by city and country.
So, thank you for choosing ViralQR; we have an offer of nothing but the best in terms of QR code services to meet business diversity!
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
4. Logging using Log4j
Log4j - logging library for Java
Logging Levels (in lowest to highest order)
The standard levels of Log4j are ordered as
ALL < TRACE < DEBUG < INFO < WARN < ERROR <
FATAL < OFF
5. Logging using Log4j
Level
Description
ALL
The lowest possible rank and is intended to turn on all levels of
logging including custom levels.
TRACE
Introduced in log4j version 1.2.12, this level gives more detailed
information than the DEBUG level.
DEBUG
Designates fine-grained informational messages that are most
useful to debug an application.
INFO
Designates informational messages that highlight the progress of
the application at coarse-grained level.
WARN
Designates potentially harmful situations. This level can be used
to warn usage of deprecated APIs, poor use of API, ‘almost’
errors and other runtime situations that are undesirable or
unexpected, but not necessarily “wrong”.
6. Logging using Log4j
Level
Description
ERROR
Designates error events that might still allow the application to
continue running. This level can be used to inform about a
serious error which needs to be addressed and may result in
unstable state.
FATAL
Designates very severe error events that will presumably lead
the application to abort.
OFF
The highest possible rank and is intended to turn off logging.
7. How Logging Level works?
A logging request of a particular level is said to be enabled if that
level is higher than or equal to the level of its logger.
Example
import org.apache.log4j.*;
public class LogClass {
private static final org.apache.log4j.Logger LOGGER =
Logger.getLogger(LogClass.class);
public static void main(String[] args) {
LOGGER.setLevel(Level.WARN);
LOGGER.trace("Trace Message!");
LOGGER.debug("Debug Message!");
LOGGER.info("Info Message!");
LOGGER.warn("Warn Message!");
LOGGER.error("Error Message!");
LOGGER.fatal("Fatal Message!");
}
}
Output:
Warn Message!
Error Message!
Fatal Message!
9. Logging - Best Practices
Declare the logger to be both static and final to ensure
that every instance of a class shares the common logger
object.
Add code to check whether logging has been enabled at
the right level.
Use meaningful log messages that are relevant to the
context.
10. Logging - Best Practices
Better to use logging only to log the following,
method entry (optionally with the method’s input
parameter values)
method exit
root cause message of exceptions that are handled at
the exception’s origin point.
11. Logging - Best Practices
Any other intermediate redundant logging statements, which
are used just for the purpose of debugging can still be
avoided.
Example
try {
LOGGER.debug(“About to enter getSkuDescription method”);
// The above logging statement is not required,
// if getSkuDescription() method logs its method entry
String skuDesc = getSkuDescription(skuNumber);
LOGGER.debug(“Exited getSkuDescription method”);
// The above logging statement is not required,
// if getSkuDescription() method logs its method exit
} catch (ServiceException se) {
LOGGER.error(se.getErrorMessage());
throw se;
}
12. Logging - Best Practices
Avoid logging at ‘every’ place where a custom exception is
thrown and instead log the custom exceptions’ message
in its ‘catch’ handler.
Example
try {
if (null == skuNumber || skuNumber.isEmpty()) {
LOGGER.error(“Sku number is invalid”);
// The above logging statement is not required,
// since the catch handler logs the message
throw new ServiceException(“Sku number is invalid”);
}
13. Logging - Best Practices
try {
sku = Integer.parseInt(skuNumber);
} catch (NumberFormatException nfe) {
LOGGER.error(“Sku number is invalid and not a number”);
// The above logging statement is not required,
// since the catch handler logs the message
throw new ServiceException(“Sku number is invalid and
not a number”, nfe);
}
……
} catch (ServiceException se) {
LOGGER.error(se.getErrorMessage());
throw se;
}
15. Exception Handling - Best Practice #1
Handle Exceptions close to its origin
Does NOT mean “catch and swallow” (i.e. suppress or ignore
exceptions)
try {
// code that is capable of throwing a XyzException
} catch ( XyzException e) {
// do nothing or simply log and proceed
}
It means, “log and throw an exception relevant to that source
layer”
– DAO layer - DataAccessException
– Business layer - ApplicationException (example OUSException)
16. Exception Handling - Best Practice #1
Important Note
In applications using Web Services, the Web Service (a.k.a
Resource) layer,
should catch ALL exceptions and handle them by creating proper
error response and send it back to client.
should NOT allow any exception (checked or unchecked) to be
“thrown” to client.
should handle the Business layer exception and all other
unchecked exceptions separately.
17. Exception Handling - Best Practice #1
Example
try {
// code that is capable of throwing an ApplicationException
} catch (ApplicationException e) {
// form error response using the exception’s
// data – error code and/or error message
} catch (Exception e) {
// log the exception related message here, since this block is
// expected to get only the unchecked exceptions
// that had not been captured and logged elsewhere in the code.
// form error response using the exception’s
// data – error code and/or error message
}
The catch handler for ‘Exception’ in the Web Service layer is expected to
handle all unchecked exceptions thrown from within ‘try’ block
18. Exception Handling - Best Practice #2
Log Exceptions just once and log it close to its origin
Logging the same exception stack trace more than once can confuse
the programmer examining the stack trace about the original source
of exception.
try {
// code that is capable of throwing a XyzException
} catch (XyzException e) {
// log the exception specific information
// throw exception relevant to that source layer
}
19. Exception Handling - Best Practice #2
#1 - When catching an exception and throwing it through an
exception relevant to that source layer, make sure to use the
construct that passes the original exception’s cause. Otherwise,
CodePro will report "No cause specified when creating exception“.
try {
// code that is capable of throwing a SQLException
} catch (SQLException e) {
// log technical SQL Error messages, but do not pass
// it to the client. Use user-friendly message instead
LOGGER.error(“An error occurred when searching for the SKU
details” + e.getMessage());
throw new DataAccessException(“An error occurred when
searching for the SKU details”, e);
}
20. Exception Handling - Best Practice #2
#2 - There is an exception to this rule, in case of existing code that
may not have logged the exception details at its origin. In such
cases, it would be required to log the exception details in the first
method up the call stack that handles that exception. But care
should be taken not to COMPLETELY overwrite the original
exception’s message with some other message when logging.
Example
DAO Layer:
try {
// code that is capable of throwing a SQLException
} catch (SQLException e) {
// LOGGING missed here
throw new DataAccessException(“An error occurred
when processing the query.”, e);
}
21. Exception Handling - Best Practice #2
Processor Layer:
try {
// code that is capable of throwing a DataAccessException
} catch (DataAccessException e) {
// logging is mandated here as it was not logged
// at its source (DAO layer method)
LOGGER.error(e.getMessage());
throw new OUSException(e.getMessage(), e);
}
22. Exception Handling - Best Practice #3
Do not catch “Exception”
Accidentally swallowing RuntimeException
try {
doSomething();
} catch (Exception e) {
LOGGER.error(e.getMessage());
}
This code
1. also captures any RuntimeExceptions that might have been
thrown by doSomething,
2. ignores unchecked exceptions and
3. prevents them from being propagated.
23. Exception Handling - Best Practice #3
Important Note (about some common RuntimeExceptions)
NullPointerException – It is the developer’s responsibility to
ensure that no code can throw it. Run CodePro and add null
reference checks wherever it has been missed.
NumberFormatException, ParseException – Catch these and
create new exceptions specific to the layer from which it is thrown
(usually from business layer) using user-friendly and non technical
messages.
24. Exception Handling - Best Practice #3
Important Note (about some common RuntimeExceptions)
Example
try {
int sku = Integer.parseInt(skuNumber);
} catch (NumberFormatException nfe) {
LOGGER.error("SKU number is invalid and not a number");
throw new OUSException("SKU number is invalid and not a
number", nfe);
}
All other unchecked exceptions (RuntimeExceptions) will be
caught and handled by the Web Service layer (as explained in Best
Practice #1).
26. Fix to common CodePro errors
"Invalid exception parameter name"
Solution
Rename the parameter to “e”
Example
try {
// code that is capable of throwing a DataAccessException
} catch (DataAccessException e) {
throw new OUSException(e.getMessage(), e);
}
27. Fix to common CodePro errors
"No cause specified when creating exception" when wrapping
an exception into another exception.
Solution
Use the construct that passes the original exception’s cause
Example
try {
// code that is capable of throwing a SQLException
} catch (SQLException e) {
LOGGER.error(e.getMessage());
throw new DataAccessException(“An error occurred
when searching for the SKU details”, e);
}