847www色视频日本,国产gaysexchina男同gay

Article Tags

All
web3.0
- All
Backend Development
Web Front-end
Database
- All
- Mysql Tutorial
- navicat
- SQL
- Redis
- phpMyAdmin
- Oracle
- MongoDB
Operation and Maintenance
- All
- Mac OS
- Linux Operation and Maintenance
- Apache
- Nginx
- CentOS
- Docker
Development Tools
- All
- VSCode
- sublime
- notepad
- git
- composer
PHP Framework
- All
- Laravel
- YII
Common Problem
- All
Other
- All
- IIS
- SEO
- Premiere
Tech
- All
- AI
- It Industry
CMS Tutorial
- All
- WordPress
Java
- All
- javaTutorial
System Tutorial
- All
- Windows Series
- LINUX
- MAC
Computer Tutorials
Hardware Tutorial
Mobile Tutorial
- All
- Mobile News
- iPhone
- Android Phone
Software Tutorial
Mobile Game Tutorial

Home

Technical Articles

Java

javaTutorial

What is the Decorator design pattern in Java?

TheDecoratordesignpatterninJavaallowsdynamicallyaddingbehaviorstoanobjectwithoutmodifyingitscodebywrappingitwithdecoratorobjectsthatextendfunctionality.1.Itusesasharedinterface(Component)forboththecoreobject(ConcreteComponent)anddecorators.2.Theabstr

Aug 23, 2025 pm 12:06 PM

JavaFX: Control the stacking order of shapes for visual effects

This document is intended to guide developers on how to control the stacking order of shapes in JavaFX applications to achieve specific visual effects, such as highlighting the location of the snake biting to itself in a gluttonous snake game. We will explore how to use the setViewOrder property to adjust the drawing order of shapes, thereby solving the problem of the toFront() method failure. Through this article, you will learn how to flexibly control the cascade relationships of JavaFX nodes in the scene and apply them to real projects.

Aug 23, 2025 am 11:51 AM

Traps and solutions for this reference and circular dependency in Java constructor

This article explores in-depth compilation errors that may cause reference to this in Java inheritance class constructors "cannot reference this before calling the superclass constructor". Focus on analyzing the cause of this error, that is, this object is in a state of incomplete initialization before the construction chain is completed. The article will use specific cases to reveal the conflict between cyclic dependencies and final fields between classes, and provide practical solutions to unblock circular dependencies and optimize the order of object construction, such as relaxing the final restrictions of fields, adopting a static factory approach, or re-examining the design pattern.

Aug 23, 2025 am 11:27 AM

Methods to access parent Activity data in child Activity in Android

This article describes how a child activity accesses data in the parent activity that started it in Android application development. Through the ViewModel method, the shared data and logic are extracted into the ViewModel, so that different activities and Fragments can access and modify these data, thereby realizing data sharing and decoupling.

Aug 23, 2025 am 11:09 AM

Spring Boot application not connected to the configuration center troubleshooting and solutions

This article aims to solve the problem that Spring Boot applications cannot get configuration from Configuration Center. By adding necessary dependencies, configuring client connection information, and checking the availability of the Configuration Center, helping developers quickly locate and resolve common causes of configuration load failures, ensuring that applications can correctly read remote configurations.

Aug 23, 2025 am 11:06 AM

Automatically assemble dependencies with Mock injection using JMockit

This article describes how to use the JMockit framework to automatically assemble dependencies with Mock injection in a test class. With @Tested and @Injectable annotations, JMockit can automatically create instances and inject Mock objects, simplifying the writing of unit tests. The article provides detailed code examples and considerations to help readers understand and apply JMockit's auto-assembly capabilities.

Aug 23, 2025 am 11:03 AM

Best practices in Java Stream for finding elements and handling default situations

This article explores in-depth ways to efficiently find matching elements and elegantly handle unfinished cases in the Java Stream API. By combining filter(), findFirst() and ifPresentOrElse(), we can implement the search logic of traditional loops in a concise and declarative way, and execute preset default behavior when elements do not exist, thereby improving the readability and robustness of the code.

Aug 23, 2025 am 10:57 AM

Resolve AWS Java SDK EC2 connection reset and XML parsing error: Switch to asynchronous client

This article aims to resolve the errors "Unable to execute HTTP request: Connection reset" and "XMLStreamException: ParseError" when accessing EC2 services using the AWS Java SDK. By analyzing the problem phenomenon, point out the possible limitations of synchronous clients when handling potential large responses, and provide a solution: replace Amazon EC2ClientBuilder with Amazon EC2AsyncClientBuilder to optimize the stability and responsive processing capabilities of EC2 API calls.

Aug 23, 2025 am 10:45 AM

Calculate the number of days, hours, minutes and seconds between two dates and times in Java

This article describes how to calculate the number of days, hours, minutes, and seconds between two dates and times using Java 8 and later. It covers parsing date and time strings, time zone processing, and calculating time difference using Duration class. The article provides clear code examples and steps to help developers deal with calculation needs in specific date and time formats.

Aug 23, 2025 am 10:36 AM

How to use flatMap in the Java Stream API

flatMap is used in JavaStreamAPI to map elements into streams and flatten nested structures, suitable for processing collections in collections. 1. It applies a function that returns Stream to each element and merges all substreams into a single stream; 2. It is often used to flatten List to a single-layer Stream; 3. It can extract collection data in an object, such as getting all hobbies from List; 4. Unlike map, flatMap supports one-to-many or zero conversion; 5. It does not skip empty sets, but it does not produce any elements; 6. Only flatten one layer of nesting. For example, using flatMap(List::stream) can merge multi-layer lists into single-layer streams and eventually collect them through collect

Aug 23, 2025 am 10:34 AM

How to parse a CSV file in Java

Parsing CSV files can be implemented in Java in many ways, and it is recommended to use third-party libraries to handle complex situations. 1. Use the OpenCSV library (recommended): First add Maven or Gradle dependencies, then read all rows through CSVReader and iterate over the output, or use CsvToBeanBuilder to map CSV rows to Java objects (such as Person class). Make sure that the CSV header matches the field name. 2. Use Java built-in class: read line by line through BufferedReader and split fields with split(","), but this method cannot handle quotation commas correctly, and it only works for simple CSV files without commas. 3

Aug 23, 2025 am 10:19 AM

Use the Stream API to find the maximum value of a Map in a List

This article describes how to use the Java Stream API to find objects with the maximum length in a List containing a HashMap. First, it is recommended to use custom objects instead of HashMap to improve code readability and type safety. Then, we explain in detail how to find a single largest element using Stream.max() and Collections.max(), and how to find multiple elements with the same maximum length using groupingBy() and collect(). Finally, a method is provided to avoid creating intermediate maps and remind readers of the importance of interface-oriented programming.

Aug 23, 2025 am 10:18 AM

Couchbase and string pool: Practice for optimizing large-scale data storage

This article explores how to use the concept of string pooling to optimize memory usage when storing large amounts of data using Couchbase. For JSON document scenarios that store a large number of duplicate strings, this article will introduce how to implement string residency through a custom Jackson deserializer, thereby effectively reducing the memory usage of Couchbase cache.

Aug 23, 2025 am 09:51 AM

Spring Boot JPA data retrieval null pointer exception check and resolution

This article aims to help developers diagnose and resolve data retrieval null pointer exceptions caused by the mismatch between the entity class field and the database column name in Spring Boot JPA project. By analyzing problem code, entity class definitions and Repository interfaces, we provide detailed troubleshooting steps and solutions to ensure that data can be loaded correctly from the database into the application.

Aug 23, 2025 am 09:48 AM