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A Guide to Transaction Management in Java and the Spring Framework

Spring's @Transactional only rolls back for RuntimeException by default. 2. It is necessary to specify the check for exceptions to be rolled back. 3. The propagation behavior REQUIRED is the default value. REQUIRES_NEW will suspend the current transaction. 4. The self-call will cause the transaction to fail due to proxy failure. 5. It is recommended to use declarative transactions at the service layer and maintain short transactions to improve performance. In the end, the transaction behavior should be verified through tests to ensure data consistency.

Aug 01, 2025 am 06:25 AM

spring framework java transaction

Full-Stack Development with Java, Spring Boot, and React

Full-stack development uses the combination of Java, SpringBoot and React to efficiently build enterprise-level applications. 1. Java SpringBoot is responsible for back-end RESTfulAPI, business logic, data persistence and security control, 2. React is responsible for front-end SPA interface, component development and state management, 3. The project structure should be separated from the front-end directories, independently developed and deployed, and solved cross-domain through CORS or agents. 4. During development, the back-end uses SpringBoot to quickly build APIs and configure JWT authentication. The front-end uses React to call the interface and encapsulate service modules. 5. The CORS problem is avoided through the agent in the joint debugging stage. The production environment can choose front-end and back-end separate deployment or front-end static file embedding.

Aug 01, 2025 am 06:19 AM

Mastering Java Concurrency and Multithreading

The core of mastering Java concurrency is to understand thread interaction, shared state risks and coordination mechanisms, rather than memorizing the API only. 1. Understand the difference between Thread and Runnable, prioritize the implementation of Runnable or Callable, and use ExecutorService to manage threads to improve resource utilization and scalability; 2. Prevent race conditions for shared variables under multi-threads through synchronized keywords or AtomicInteger, and use CAS to achieve efficient lock-free operation; 3. Use thread-safe sets such as ConcurrentHashMap, CopyOnWriteArrayList and BlockingQueue.

Aug 01, 2025 am 06:16 AM

Building Resilient Java Systems with Resilience4j

Resilience4j is the core library used to build elastic Java applications. 1. Its modules include CircuitBreaker, RateLimiter, Retry, Bulkhead, TimeLimiter and Cache, which can be used on demand. 2. CircuitBreaker prevents cascade failures by configuring failureRateThreshold and other parameters, and uses decorateSupplier to wrap service calls; 3. Retry can be combined with RateLimiter, limit the current and then try again to avoid downstream service overload; 4. In SpringBoot, you can use annotations such as @CircuitBr

Aug 01, 2025 am 06:16 AM

State of the Java Ecosystem in 2024

Asof2024,Javaremainsadominantandevolvingforceinenterpriseandcloud-nativedevelopment.1.Java21(LTS)iswidelyadopted,withJava22released,featuringkeyupdateslikerecords,patternmatching,sealedclasses,andvirtualthreads—revolutionizingconcurrency.2.SpringBoot

Aug 01, 2025 am 06:15 AM

java ecosystem

Common Anti-Patterns to Avoid in Java Development

AvoidGodClassesbysplittingresponsibilitiesintofocusedclassesusingSRPanddesignpatternslikeServiceandRepository.2.CombatPrimitiveObsessionbycreatingvalueobjectsthatencapsulatedomainlogicandvalidation.3.Limitstaticmethodstoutilities;usedependencyinjecti

Aug 01, 2025 am 06:10 AM

Diagnosing and Fixing Java OutOfMemoryError

First, clarify the type of the problem, and then solve it in a targeted manner: 1. Based on the error information, determine whether the Java heap space, Metaspace, thread creation failed or GC overhead is too high; 2. Enable GC logs and use tools to analyze memory trends; 3. Generate heap dump files when an error occurs, and use tools such as EclipseMAT to locate the memory leak source; 4. Use tools such as jstat, jmap, and jconsole to monitor memory and GC status during runtime; 5. Adjust the heap size according to the root cause, set the upper limit of Metaspace, repair memory leaks (such as static collections not being cleaned and resources not being closed), and use thread pools to control the number of threads reasonably; 6. Preventive measures include using bounded cache, memory analysis in performance testing, and production environment

Aug 01, 2025 am 06:06 AM

What are common causes of memory leaks in Java applications?

Staticfieldsholdingobjectreferencescanpreventgarbagecollection;fixbyusingWeakHashMaporimplementingeviction.2.Improperuseoflistenersandcallbacksmayretainobjectsunnecessarily;fixbyunregisteringlistenersorusingweakreferencesandstaticinnerclasses.3.Unclo

Aug 01, 2025 am 06:03 AM

java memory leak

A Deep Dive into Java HashMap and Its Performance

HashMap is implemented in Java through array linked lists/red and black trees. Its performance is affected by the initial capacity, load factor, hash function quality and the immutability of the keys; 1. Use (n-1)&hash to calculate the index to improve efficiency; 2. When the linked list length exceeds 8 and the number of buckets is ≥64, it will be converted to a red and black tree, so that the worst search complexity is reduced from O(n) to O(logn); 3. Rehash all elements when expanding, the overhead is high, and the capacity should be preset; 4. The key must be rewrite hashCode and equals correctly; 5. ConcurrentHashMap should be used in multi-threaded scenarios; the average time complexity is O(1) under reasonable use, but improper use will lead to performance degradation.

Aug 01, 2025 am 05:54 AM

Mastering Dependency Injection in Java with Spring and Guice

DependencyInjection(DI)isadesignpatternwhereobjectsreceivedependenciesexternally,promotingloosecouplingandeasiertestingthroughconstructor,setter,orfieldinjection.2.SpringFrameworkusesannotationslike@Component,@Service,and@AutowiredwithJava-basedconfi

Aug 01, 2025 am 05:53 AM

java dependency injection

Modern Java Build and Dependency Management with Maven and Gradle

Mavenisidealforstandardized,enterpriseenvironmentswithitsXML-based,convention-over-configurationapproach,while2.GradleexcelsinflexibilityandperformanceusingGroovyorKotlinDSL,makingitbetterforcomplex,large-scale,orAndroidprojects,3.bothsupportrobustde

Aug 01, 2025 am 05:25 AM

Optimizing Java Performance: A Guide to Garbage Collection Tuning

Choosing the right garbage collector and configuring it properly is the key to optimizing Java application performance. First, select the GC type according to application needs: SerialGC is used for small memory applications, ParallelGC is used for high throughput scenarios, G1GC is used for large memory and controllable pauses, and ZGC is used for ultra-low latency requirements (such as financial transactions). 1. Set the heap size reasonably to avoid being too large or too small. It is recommended that -Xms and -Xmx are equal to -Xmx to prevent dynamic expansion; 2. For G1GC, you can set the target pause time through -XX:MaxGCPauseMillis, adjust -XX:G1HeapRegionSize to deal with large objects, and use -XX:InitiatingHea

Aug 01, 2025 am 05:12 AM

Garbage collection java performance

Exploring Virtual Threads in Java with Project Loom

VirtualthreadsinJava—introducedaspartofProjectLoom—areagame-changerforwritinghigh-throughput,concurrentapplicationswithouttheusualcomplexityofasyncprogrammingorthreadpooling.Ifyou’veeverstruggledwithblockingI/Ooperationss

Aug 01, 2025 am 05:03 AM

java 虛擬線程

How to perform a deep copy of an object in Java?

To implement deep copy in Java, new objects must be created and all nested objects recursively copy to avoid sharing mutable states. The specific methods include: 1. Manual deep copy using copy constructor. The advantages are type safe and controllable, and the disadvantages are cumbersome and error-prone; 2. Use serialization to achieve deep copy through byte streams, which can automatically process complex objects but require all classes to achieve Serializable and have low performance; 3. Use ApacheCommonsLang's SerializationUtils to simplify the serialization process, but is also limited by Serializable requirements; 4. Use JSON libraries such as Gson or Jackson to serialize objects to JSON and deserialize them, which is suitable for non-Se

Aug 01, 2025 am 05:01 AM

java deep copy