java-design-patterns | Design patterns implemented in Java | Architecture library

by iluwatar Java Version: 1.25.0 License: Non-SPDX

kandi X-RAY | java-design-patterns Summary

java-design-patterns is a Java library typically used in Architecture applications. java-design-patterns has no bugs, it has no vulnerabilities, it has build file available and it has medium support. However java-design-patterns has a Non-SPDX License. You can download it from GitHub.

Design patterns are the best, formalized practices a programmer can use to solve common problems when designing an application or system. Design patterns can speed up the development process by providing tested, proven development paradigms. Reusing design patterns help prevent subtle issues that cause major problems, and it also improves code readability for coders and architects who are familiar with the patterns.

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java-design-patterns has a medium active ecosystem.
It has 79243 star(s) with 24525 fork(s). There are 3827 watchers for this library.
It had no major release in the last 6 months.
There are 187 open issues and 652 have been closed. On average issues are closed in 543 days. There are 15 open pull requests and 0 closed requests.
It has a neutral sentiment in the developer community.
The latest version of java-design-patterns is 1.25.0

java-design-patterns Support

Best in #Architecture

Average in #Architecture

java-design-patterns Support

Best in #Architecture

Average in #Architecture

quality kandi Quality

java-design-patterns has 0 bugs and 0 code smells.

java-design-patterns Quality

Best in #Architecture

Average in #Architecture

java-design-patterns Quality

Best in #Architecture

Average in #Architecture

security Security

java-design-patterns has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
java-design-patterns code analysis shows 0 unresolved vulnerabilities.
There are 0 security hotspots that need review.

java-design-patterns Security

Best in #Architecture

Average in #Architecture

java-design-patterns Security

Best in #Architecture

Average in #Architecture

license License

java-design-patterns has a Non-SPDX License.
Non-SPDX licenses can be open source with a non SPDX compliant license, or non open source licenses, and you need to review them closely before use.

java-design-patterns License

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Average in #Architecture

java-design-patterns License

Best in #Architecture

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build Reuse

java-design-patterns releases are not available. You will need to build from source code and install.
Build file is available. You can build the component from source.
Installation instructions are available. Examples and code snippets are not available.
java-design-patterns saves you 24174 person hours of effort in developing the same functionality from scratch.
It has 51260 lines of code, 4363 functions and 1743 files.
It has low code complexity. Code complexity directly impacts maintainability of the code.

java-design-patterns Reuse

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java-design-patterns Reuse

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Top functions reviewed by kandi - BETA

kandi has reviewed java-design-patterns and discovered the below as its top functions. This is intended to give you an instant insight into java-design-patterns implemented functionality, and help decide if they suit your requirements.

init data .

Handle usage processing event

Create the view .

Executes a new bake for the given parameters .

Round round .

Generates an iterable that returns the last element of the iterable .

Creates a promotion .

Handles incoming message .

Setup the panel .

Process event loop .

Get all kandi verified functions for this library.

java-design-patterns Key Features

Design patterns implemented in Java

java-design-patterns Examples and Code Snippets

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Community Discussions

Trending Discussions on java-design-patterns

How to properly implement Optimistic Locking at the application layer?

Trending Discussions on java-design-patterns

QUESTION

How to properly implement Optimistic Locking at the application layer?

Asked 2021-Mar-03 at 22:15

I am a little confused as to why Optimistic Locking is actually safe. If I am checking the version at the time of retrieval with the version at the time of update, it seems like I can still have two requests enter the update block if the OS issues an interrupt and swaps the processes before the commit actually occurs. For example:

latestVersion = vehicle.getVersion();
if (vehicle.getVersion() == latestVersion) {
    // update record in database
} else {
    // don't update record 
}

In this example, I am trying to manually use Optimistic Locking in a Java application without using JPA / Hibernate. However, it seems like two requests can enter the if block at the same time. Can you please help me understand how to do this properly? For context, I am also using Java Design Patterns website as an example.

ANSWER

Answered 2021-Mar-03 at 22:15

Well... that's the optimistic part. The optimism is that it is safe. If you have to be certain it's safe, then that's not optimistic.

The example you show definitely is susceptible to a race condition. Not only because of thread scheduling, but also due to transaction isolation level.

A simple read in MySQL, in the default transaction isolation level of REPEATABLE READ, will read the data that was committed at the time your transaction started.

Whereas updating data will act on the data that is committed at the time of the update. If some other concurrent session has updated the row in the database in the meantime, and committed it, then your update will "see" the latest committed row, not the row viewed by your get method.

The way to avoid the race condition is to not be optimistic. Instead, force exclusive access to the record. Doveryai, no proveryai.

If you only have one app instance, you might use a critical section for this.

If you have multiple app instances, critical sections cannot coordinate other instances, so you need to coordinate in the database. You can do this by using pessimistic locking. Either read the record using a locking read query, or else you can use MySQL's user-defined locks.

Source https://stackoverflow.com/questions/66465456

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install java-design-patterns

This site showcases Java Design Patterns. The solutions have been developed by experienced programmers and architects from the open-source community. The patterns can be browsed by their high-level descriptions or by looking at their source code. The source code examples are well commented and can be thought of as programming tutorials on how to implement a specific pattern. We use the most popular battle-proven open-source Java technologies. Before you dive into the material, you should be familiar with various Software Design Principles. All designs should be as simple as possible. You should start with KISS, YAGNI, and Do The Simplest Thing That Could Possibly Work principles. Complexity and patterns should only be introduced when they are needed for practical extensibility. Once you are familiar with these concepts you can start drilling down into the available design patterns by any of the following approaches. Hopefully, you find the object-oriented solutions presented on this site useful in your architectures and have as much fun learning them as we had while developing them.
Search for a specific pattern by name. Can't find one? Please report a new pattern here.
Using tags such as Performance, Gang of Four or Data access.
Using pattern categories, Creational, Behavioral, and others.

Support

If you are willing to contribute to the project you will find the relevant information in our developer wiki. We will help you and answer your questions in the Gitter chatroom.

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