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Client remotely executes server-side GUI applications: Download and start tutorial

This tutorial details the complete process of how a client downloads and runs a GUI application locally from the server. Through Java code examples, we will learn how to use URL and file operations to download JAR packages and use ProcessBuilder to launch the GUI application in the client environment, while providing important security and version management considerations.

Aug 25, 2025 am 05:15 AM

What does the static keyword signify in Java?

StaticinJavabelongstotheclass,notinstances,andenablessharingacrossallobjectswithoutinstantiation.1.Staticvariablesaresharedamongallinstances,withonlyonecopyexisting,suchasstaticintcountinaCounterclassthatincrementswitheachobjectcreation.2.Staticmetho

Aug 25, 2025 am 04:41 AM

java static

Building Event-Driven Systems in Java with Apache Kafka

To build an event-driven system using Java and ApacheKafka, you must first master the core concept of Kafka and implement producers and consumers in steps. 1. Understand the role of topics, partitions, producers, consumers, consumer groups and Brokers to achieve service decoupling. 2. Introduce kafka-clients dependencies in Java projects, write producer code to send events to specified topics, such as user login messages. 3. Create consumer subscription topics, get messages through polling and process business logic, and support horizontal scaling. 4. Follow best practices: Use SchemaRegistry to manage event structure, ensure consumer idempotence, process failed messages to dead letter queues, monitor consumption lag, and reasonably design partitions

Aug 25, 2025 am 03:56 AM

Spring Data JPA projection: efficient query and partial data mapping

This article explores in-depth how to use Spring Data JPA's Projections functionality in Spring Boot applications to efficiently select specific fields from the database and map to custom interfaces or DTO objects instead of complete entity classes. This solves the ConversionFailedException problem that occurs when directly mapping part of the query results (such as Object[]) to an entity, thereby optimizing the performance and flexibility of data retrieval.

Aug 25, 2025 am 03:36 AM

The Difference Between `String`, `StringBuilder`, and `StringBuffer` in Java

Stringisimmutableandthread-safe,makingitsuitableforconstanttextandscenariosrequiringnomodification;2.StringBuilderismutableandnotthread-safe,offeringhighperformanceforsingle-threadedstringmanipulations;3.StringBufferismutableandthread-safeduetosynchr

Aug 25, 2025 am 03:06 AM

java string

How to use constructors in Java

Java constructor is a special method used to initialize objects. It must be the same name as the class name and has no return type; 1. The constructor is automatically called when the object is created and is used to set the field initial value; 2. It is divided into default constructor (no parameters, automatically provided by Java), custom parameterless constructor and parameterized constructor; 3. It supports constructor overloading, allowing multiple constructors with different parameter lists in the same class; 4. The constructor chain call can be implemented through this() to reduce duplicate code; 5. After defining any constructor, Java no longer provides the default parameterless constructor; 6. The constructor can be used to verify input, ensure the validity of the object state, and improve the robustness of the class. Correct use of constructors ensures that the object is always in a consistent initial state

Aug 25, 2025 am 02:33 AM

What is the finally block in Java?

ThefinallyblockinJavaalwaysexecutesafterthetry-catchblock,regardlessofwhetheranexceptionoccursorareturnstatementisencountered,makingitidealforcleanuptaskslikeclosingfilesorreleasingresources;itrunsevenifanexceptionisthrownandnotcaught,orifamethodexit

Aug 25, 2025 am 01:50 AM

What is JDBC in Java?

JDBC,orJavaDatabaseConnectivity,isastandardAPIthatenablesJavaapplicationstointeractwithrelationaldatabaseslikeMySQL,PostgreSQL,Oracle,andSQLServerbyactingasabridgebetweenthem.ThekeycomponentsincludeDriverManagerformanagingdatabasedriversandestablishi

Aug 24, 2025 pm 03:04 PM

java jdbc

How to use a List in Java

ChooseArrayListformostusecasesduetobetterperformance,orLinkedListforfrequentinsertions/deletions;2.Addelementswithadd(),accesswithget(),andchecksizewithsize();3.Modifyelementsusingset()andremoveelementsviaremove()byindexorvalue,avoidinginvalidindexes

Aug 24, 2025 pm 02:00 PM

How to create a custom annotation in Java

Definition annotations Use the @interface keyword to create custom annotations and set elements and their default values; 2. Use @Target, @Retention and other meta annotations to control the applicable goals, retention policies and other behaviors of annotations; 3. Apply custom annotations on program elements such as classes and methods, and use full parameters or abbreviations; 4. Read annotation information at runtime through reflection, and be sure to use RetentionPolicy.RUNTIME retention policy; custom annotations enhance the code function through metadata, and combine reflection to achieve flexible runtime processing, and end completely.

Aug 24, 2025 pm 01:54 PM

The Ultimate Guide to Java Interview Questions for Senior Roles

SeniorJavainterviewstestdeeptechnicalexpertise,requiringmasteryofconcurrency,JVMinternals,systemdesign,advancedlanguagefeatures,andSpring.2.Forconcurrency,understandsynchronized,ReentrantLock,JMM,andtoolslikejstackandjmh,andproviderealexamplesofreduc

Aug 24, 2025 pm 01:41 PM

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How to create a scheduled task in Java?

UseScheduledExecutorServiceforschedulingtasksinJava,asitsupportsthreadpoolingandbettererrorhandling.2.CreateaScheduledExecutorServiceinstanceusingExecutors.newSingleThreadScheduledExecutor().3.DefinethetaskasaRunnabletobeexecuted.4.Schedulethetaskusi

Aug 24, 2025 pm 01:40 PM

What is the difference between Stream.map() and Stream.flatMap() in Java?

ThekeydifferenceisthatStream.map()performsaone-to-onetransformation,mappingeachelementtoexactlyonenewelement,whileStream.flatMap()performsaone-to-manytransformationbyconvertingeachelementintoastreamandthenflatteningallstreamsintoasinglestream;forexam

Aug 24, 2025 pm 01:21 PM

Responsive stream processing null values ??and custom exception throwing in Spring WebFlux

This article aims to explore how to gracefully handle null values ??that may appear in responsive streams in Spring WebFlux responsive programming and throw a custom exception when null is detected. We will dig into why using map directly with switchIfEmpty or filter cannot achieve the expected results, and provide two recommended solutions: flatMap and handle operators to ensure the robustness of responsive streams and the accuracy of error handling.

Aug 24, 2025 pm 12:18 PM