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This article mainly introduces how to use JavaWeb DWR, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

We understand that things are used to connecting unknown from the known. First of all, let's compare it. The first thing we learn about is the waterfall model, so it is not agile. The waterfall development pattern divides the development into a series of stages, such as requirements, design, development, and testing, as shown in the following figure, which looks like a waterfall, so it is called waterfall development.

The question is, doesn't the delivery of requirements all go through these stages?

The essential problem of waterfall development is not stage, but batch. Requirements are designed in batches, followed by batch development, batch testing, delivery, and so on. What's wrong with the batch? First of all, volume delay value delivery, all requirements can be delivered in the final stage, value delivery is relatively late. Schmidt, executive chairman of Google, put forward the inverse Moore's Law, which states: "if in 18 months we can only sell the same thing as we do today, we will only get half the income." The delivery time of value will have a direct impact on revenue.

Agile goal 1:

The first goal of agile development is to deliver value faster, and fast here does not mean absolute speed, but earlier delivery.

At the end of the project, it must be the time to have the best knowledge of the product and the project. It is obvious that we have accumulated knowledge in the process of the project, especially when the product is delivered to the user, the user feedback: "that's not what I want, I'm talking about..."... " At this time, you suddenly soared your knowledge and sighed, "Why didn't you say so earlier?" . There may be communication problems, but it is more likely that users will be clear or able to describe what they want, and what's more, we may not be able to define exactly who the user is at first. Product and business development is a process of exploration, and it must be the most ignorant moment at the beginning.

Most of the decisions in the project must also be made at the beginning of the project, which will be a major paradox that, at the most ignorant moment, the most important and vast majority of decisions are made and used as a basis for subsequent implementation. In the face of uncertain technology and market environment, the traditional development model has been unable to meet the requirements, and the paradox is becoming more and more prominent.

Agile development will deal with this problem through iteration, making only initial decisions and setting a general direction. Constantly revise the product perception, incremental decision-making and adjustment through market feedback.

Agile goal 2:

In the process of product development, the technical environment, market environment, competitive strategy and team cognition will change. In the face of the changing environment, we must admit our ignorance, learn actively and effectively in the development process, constantly draw feedback, and adjust flexibly. This is also Agile's second business goal, to learn effectively and respond flexibly to change.

Agile process

Agile development is a method that takes people as the core and develops step by step in an iterative way. the process of software development is called "agile process".

In this process, the construction of the software project is divided into multiple sub-projects, and the success of each sub-project has been tested and has the characteristics of integration and operation.

In early 2001, some industry experts formed the Agile Alliance and drafted the Agile Software Development Manifesto. In view of the current situation of some enterprises, the declaration puts forward a number of values and principles that make software development teams have the ability to work quickly and respond quickly, including 4 simple values and 12 principles that agile development methods should follow.

The values of Agile Development

1. Individuals and interactions outweigh processes and tools.

two。 Software that can be run is better than comprehensive documentation.

3. Customer cooperation is better than contract negotiation.

4. It is better to respond to changes than to follow a plan.

12 principles to be followed in Agile Development

1. Customer satisfaction through the early and continuous delivery of valuable software.

two。 Even in the late stages of development, changes in requirements are welcome. Agile processes use change to create a competitive advantage for customers.

3. Submit runnable software as soon as possible and continuously on a cycle from weeks to months.

4. Business people and developers must work together every day throughout the development of the project.

5. Focus on positive employees, set up a project team, provide them with the environment and support they need, and have full trust in their work.

6. Within the team, the most effective and efficient way to convey information is face-to-face communication.

7. The primary basis for measuring the progress of a project is runnable software.

8. Agile processes promote sustainable development, and responsible people, developers, and users should strive to maintain a long-term and constant development speed.

9. Always pay attention to technical excellence and good design to enhance agility.

10. Simplicity is the most fundamental.

11. The best architecture, requirements, and design come from self-organizing teams.

twelve。 At regular intervals, the team reflects on how to work more effectively, and then adjusts its behavior accordingly.

There are three main overall frameworks of agile development models proposed by agile organizations:

Scrum, XP (eXtreme Programming), and OpenUP are three agile practices.

Principles of Agile Development

1. Unite the strength of people and work closely together. Including the relationships between business leaders, development teams, customers, and managers, all of which have been one of the causes of project crises in the past, we need these roles to work closely together in the agile era. maximize the power of each role.

two。 Focus on customer value and eliminate waste (how to focus on user value, that is, frequently deliver user workable software and receive user feedback quickly)

Agile team operation mechanism

1. A team has its own to-do list, which is small to deal with.

two。 Prioritize according to customer value, and the product manager is responsible for value ranking.

3. Small and stable, cross-functional team.

4. Multiple teams are loosely coupled (with low dependencies) to align iteration time and strategic goals.

Key team roles

Product owner

Scrum Supervisor (process Supervisor)

Development team

Product owner (Product Owner)

The only person in charge of managing the product backlog (to-do list)

Represent the client / project such as the responsible person

Define all the features of the product

Responsible for the input and output of products

Responsible for maximizing the value of product and development team work

Scrum Master (process Manager)

Play the role of a coach, lead the team to complete the practice of Scrum and demonstrate its value.

Eliminate the difficulties encountered by the team, make the team work closely, and make the team individual have the ability to work in many aspects.

Ensure that the team is competent and productive.

Protect the team from external unprovoked influence

Key team activities

Daily meeting: a simple meeting of about 5 minutes a day in which as many developers as possible participate in the discussion of critical issues.

Review meeting: it needs to be held on the last day of the iterative cycle, about 1 hour, and the customer is required to attend. If the customer cannot attend, the product manager is required to attend.

Iterative retrospective session: the iterative review will be conducted at the end of each iteration to summarize the experiences and lessons learned in the work. The time will be maintained within 30-60 minutes, and the entire team will need to participate (Scrum Master, Product Owner, development team, and customers). The iterative review will consist of two parts, the first part is quantitative analysis and the second part is qualitative analysis. The quantitative analysis includes whether the team has achieved the iterative goals, collecting and reviewing iterative metrics (including rate, iterative burnout diagram, iterative planned and actual completion stories, planned and actual release dates, customer satisfaction, team satisfaction, production environment Bug, production Bug resolution time, user stories, etc.). Qualitative analysis includes what work is good (should continue to be maintained) and which is not good (should be stopped)? What can be improved (the team chooses 1mi 2 to be implemented in the next iteration)?

Thank you for reading this article carefully. I hope the article "how to use JavaWeb DWR" shared by the editor will be helpful to everyone. At the same time, I also hope that you will support and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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