Go language can be used for scientific calculations and numerical analysis, but it needs to be understood. The advantage lies in concurrency support and performance, which is suitable for parallel algorithms such as distributed solution, Monte Carlo simulation, etc.; community libraries such as gonum and mat64 provide basic numerical calculation functions; hybrid programming can be used to call C/C and Python through Cgo or interface to improve practicality. The limitation is that the ecosystem is not as mature as Python, the visualization and advanced tools are weaker, and some library documents are incomplete. It is recommended to select appropriate scenarios based on Go features and refer to source code examples to use them in depth.

Understand core components: Producers publish events to Topics, Consumers subscribe and process events, KafkaBroker manages message storage and delivery; 2. Locally build Kafka: Use Docker to quickly start ZooKeeper and Kafka services, expose port 9092; 3. Java integration Kafka: introduce kafka-clients dependencies, or use SpringKafka to improve development efficiency; 4. Write Producer: configure KafkaProducer to send JSON format order events to orders topic; 5. Write Consumer: Subscribe to o through KafkaConsumer

How to get started with AngularMaterial? First run ngadd@angular/material to install and configure, secondly, introduce components such as MatButtonModule as needed, then import and use components in the module, and finally add global styles and fonts; the advantages of AngularMaterial include a unified design language, rich components, good documentation and community support, and strong customization; other alternatives include NG-ZORRO, PrimeNG, ClarityDesign and IonicforAngular, and when choosing, you should consider comprehensively based on project needs and team familiarity.

The core of optimizing front-end build time is to reduce redundant work, improve processing efficiency, utilize caches and select efficient tools. 1. Use TreeShaking and code segmentation reasonably to ensure that it is introduced on demand and dynamic import reduces the packaging volume; 2. Reduce unnecessary loader processing, exclude node_modules, upgrade loaders and relax the scope of Babel translation; 3. Use the caching mechanism to speed up repeated construction, enable Webpack cache, CI cache and use offline installation; 4. Upgrade toolchain, such as using Vite, esbuild or Rollup to improve the construction speed, although there is migration cost, it has significant effect.

Confirm that the NativeMemory problem is manifested as normal heap memory but the total process memory is growing, the RES memory is far beyond the -Xmx setting, and an OOM error of Directbuffer or nativethread. 1. Use NMT (-XX:NativeMemoryTracking=summary) to track the native memory of JVM and view the memory trends of modules such as Thread and Internal through jcmd; 2. Pay attention to the DirectBuffer leakage, it is not released when using allocateDirect() or the MaxDirectMemorySize setting is unreasonable; 3. Check that too many threads lead to high stack space occupancy, which can be used

The equals() and hashCode() methods must be rewrite correctly at the same time, otherwise the hash set (such as HashMap and HashSet) will be invalid; 2. Equals() is used to define the logical equality of objects, and the actual field values need to be compared instead of references; 3. HashCode() returns the object hash code, and it is necessary to ensure that the equal objects have the same hash value; 4. Violating the contract will make it impossible to find the stored object from the collection, because hash search first uses hashCode() to locate the bucket, and then uses equals() to confirm the match; 5. It is recommended to use Objects.equals() and Objects.hash() to implement null safe and consistent logic, and avoid objects used as keys.

Master the core data structure and its applicable scenarios, such as the selection of HashMap and TreeMap, and the expansion mechanism of ArrayList; 2. Practice algorithms from the Java perspective, proficient in double pointer, sliding window, DFS/BFS and other modes and can be clearly implemented; 3. Write clean and robust Java code, pay attention to naming, boundary processing and language features (such as generics and final); 4. Prepare the practical question of "why use Java" and understand the impact of StringBuilder, GC, etc. on performance; maintain practice and clear expression to stand out.

The core methods to prevent SQL injection include: 1. Use PreparedStatement precompiled statements to ensure that the input is processed as data; 2. Whitelist verification, length limit and special character escape of the input; 3. Correctly use ORM frameworks such as Hibernate and MyBatis to avoid splicing SQL; 4. Do not expose error information, scan for vulnerabilities regularly, and restrict database permissions. These measures jointly ensure the SQL security of Java applications.