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Implementing a Caching Layer in a Java Application with Redis

RedisisusedforcachinginJavaapplicationstoimproveperformancebyreducingdatabaseloadandenablingfastdataretrieval.1.InstallRedisusingDocker:dockerrun-d-p6379:6379redis.2.Addspring-boot-starter-data-redisandlettuce-coredependenciesinpom.xml.3.ConfigureRed

Jul 30, 2025 am 03:30 AM

Building RESTful APIs in Java with Jakarta EE

SetupaMaven/GradleprojectwithJAX-RSdependencieslikeJersey;2.CreateaRESTresourceusingannotationssuchas@Pathand@GET;3.ConfiguretheapplicationviaApplicationsubclassorweb.xml;4.AddJacksonforJSONbindingbyincludingjersey-media-json-jackson;5.DeploytoaJakar

Jul 30, 2025 am 03:05 AM

java

How to Manage Dependencies in a Large-Scale Java Project

UseMavenorGradleconsistentlyforreliabledependencymanagementwithclearscopesandcentralizedconfiguration.2.Structurelargeprojectsintomulti-moduleswithaparentPOMorrootprojecttomanageshareddependenciesandenablereusewhileavoidingcycles.3.Strictlycontrolver

Jul 30, 2025 am 03:04 AM

Comparing Java, Kotlin, and Scala for JVM Development

Kotlinoffersthebestbalanceofconcisesyntaxandreadability,reducingboilerplatecomparedtoverboseJava,whileavoidingScala’scomplexityandreadabilityissues.2.JavaandKotlinleadinecosystemintegrationwithfullsupportforframeworkslikeSpringandAndroid,whereasScala

Jul 30, 2025 am 03:00 AM

How to use Java MessageDigest for hashing (MD5, SHA-256)?

To generate hash values using Java, it can be implemented through the MessageDigest class. 1. Get an instance of the specified algorithm, such as MD5 or SHA-256; 2. Call the .update() method to pass in the data to be encrypted; 3. Call the .digest() method to obtain a hash byte array; 4. Convert the byte array into a hexadecimal string for reading; for inputs such as large files, read in chunks and call .update() multiple times; it is recommended to use SHA-256 instead of MD5 or SHA-1 to ensure security.

Jul 30, 2025 am 02:58 AM

java

Implementing Authentication and Authorization in a Java Web App

UseSpringSecurityforrobust,standard-compliantauthenticationandauthorizationinJavawebapplications.2.Implementauthenticationviaform-basedloginorJWTforstatelessAPIs,ensuringpasswordsarehashedwithBCryptandtokensaresecurelymanaged.3.Applyauthorizationusin

Jul 30, 2025 am 02:58 AM

Authentication java web

Java NIO and Asynchronous I/O Explained

The main differences between JavaNIO and AsynchronousI/O are: 1. JavaNIO adopts Reactor mode, polls ready events of multiple channels through Selector, and uses a single thread to process multiplexed I/O, which is suitable for high-concurrency network servers and fine control; 2. AsynchronousI/O adopts Proactor mode, based on event-driven and callback mechanisms, notifying the completion processor when the operation is completed, truly realizing asynchronous non-blocking, suitable for extremely scalable and low-latency systems; 3. The NIO thread model is simple, has good compatibility, but requires manual management of buffers and states. Although AIO does not need to be polled and has high resource utilization, it is complex in programming, easy to fall into callback hell and relies on operations.

Jul 30, 2025 am 02:50 AM

异步i/o java nio

What is the super keyword in Java?

The super keyword is used in Java to refer to the parent class of the current object. Its main uses include accessing the parent class method, calling the parent class constructor, and resolving field name conflicts. 1. Access the parent class method: When the child class overrides the parent class method, the parent class version can be called through super.method() to extend its behavior rather than completely replace it; 2. Call the parent class constructor: super() or super(args) is used in the child class constructor to initialize the parent class field, and the statement must be located on the first line of the child class constructor; 3. Resolve field name conflicts: If the child class defines the same name field as the parent class, super.fieldName can be used to explicitly access the parent class field.

Jul 30, 2025 am 02:49 AM

Java Concurrency: Locks, Conditions, and Synchronizers

The Lock interface provides more flexible lock control than synchronized, supporting attempt acquisition, interruption, timeout acquisition and fair lock; 2. Condition allows accurate inter-thread communication through multiple condition variables to avoid false wake-up; 3. Common Synchronizers include CountDownLatch for waiting for multiple tasks to complete, CyclicBarrier for multi-thread synchronization to reach barrier points, Semaphore for controlling the number of concurrent threads, and Phaser for phased synchronization of dynamic threads; when using it, the simplicity of synchronized must be given priority, Lock must combine try-finally to prevent deadlocks, Cond

Jul 30, 2025 am 02:48 AM

Performance Implications of Java Boxing and Unboxing

Boxing will frequently create objects, increasing memory overhead and GC pressure; 2. The cache is only valid for small-scale values such as Integer between -128 and 127, and objects will still be created in large quantities after they are exceeded; 3. Null value checks are required when unboxing, which may cause NullPointerException and bring additional performance losses; 4. The use of wrapper classes in the collection will cause frequent boxing and unboxing during traversal and calculation, affecting the locality of the CPU cache; priority should be given to the use of basic type arrays or native collection libraries such as FastUtil to reduce performance overhead and avoid implicit type conversion in hotspot code.

Jul 30, 2025 am 02:44 AM

java performance

Thread Safety in Java: A Guide to `volatile` and `synchronized`

Both volatile and synchronized solve thread safety problems in Java, but their functions are different: 1. volatile ensures the visibility of variables, ensures that read and write directly interact with the main memory under multi-threading, and is suitable for single-time read and write scenarios such as status flags, but does not provide atomicity; 2. synchronized provides atomicity and visibility, and ensures that only one thread executes code block at the same time through mutex locks, which is suitable for composite operations such as count; 3. volatile cannot replace synchronized, and for non-atomic operations, synchronized or concurrent tool classes such as AtomicInteger are still required. Correct selection of tools can ensure thread safety and

Jul 30, 2025 am 02:43 AM

Managing Java Dependencies with Maven vs Gradle

Gradleisbetterforperformance,flexibility,andmodernprojects,whileMavenexcelsinsimplicityandcompatibility.1.GradleusesconciseDSL(Groovy/Kotlin),MavenusesverboseXML.2.Gradleoffersfasterbuildsviaincrementalcompilationandcaching;Mavenisslower.3.Gradleallo

Jul 30, 2025 am 02:42 AM

A Developer's Guide to Maven for Java Project Management

Maven is a standard tool for Java project management and construction. The answer lies in the fact that it uses pom.xml to standardize project structure, dependency management, construction lifecycle automation and plug-in extensions; 1. Use pom.xml to define groupId, artifactId, version and dependencies; 2. Master core commands such as mvnclean, compile, test, package, install and deploy; 3. Use dependencyManagement and exclusions to manage dependency versions and conflicts; 4. Organize large applications through multi-module project structure and are managed uniformly by the parent POM; 5.

Jul 30, 2025 am 02:41 AM

java maven

Using Records and Sealed Classes in Modern Java

Use records to create immutable data carriers, which automatically generate constructors, accessors, equals, hashCode and toString methods, suitable for DTO or simple domain models; 2. Use sealed classes to restrict inheritance systems, use permits keyword to clearly define the subclasses allowed, realize a closed type hierarchy, and improve the exhaustion and security of switch expressions; 3. Combine records with sealed classes to build a data model with type-safe, clear structure, and easy pattern matching, such as algebraic data types or expression trees, thereby improving the readability, maintainability and correctness of the code.

Jul 30, 2025 am 02:37 AM

java programming