After following, you can keep track of his dynamic information in a timely manner
Follow naming specifications to make the code as easy to read as prose; 2. The method should be small and focused, and a single responsibility is easy to test and reuse; 3. Write meaningful comments to explain "why", rather than obvious operations; 4. Prioritize immutability and packaging to prevent external accidental modifications; 5. Exceptions should be properly handled without ignoring and providing clear information; 6. Unit tests should be clearly named and cover key paths; 7. Reasonable use of modern Java features such as var and Stream to improve readability; 8. Organization of package structures layered by functions to improve project navigation efficiency - these practices jointly ensure that Java code is maintained for a long time.
Jul 31, 2025 am 06:21 AM
First use java-Xlog:startuptime and other JVM flags to measure the startup time, clarify the class loading, GC pause and main() start time; 2. Then use async-profiler or JFR to generate flame graphs to locate hot spots such as Springrefresh() or ClassLoader.defineClass; 3. Optimize for bottlenecks: streamline the dependency and enable CDS to reduce class loading time, configure Spring lazy loading and eliminate useless automatic configuration, avoid running-time resource scanning, and close the C2 compiler or use GraalVMAOT if necessary; 4. Remeasure the verification effect after each adjustment to ensure that the improvement is real and effective - through measurement, analysis, optimization,
Jul 31, 2025 am 06:20 AM
Install and run PostgreSQL, create databases and users, and ensure the service starts; 2. Add PostgreSQLJDBC drivers through Maven, Gradle or manual; 3. Write connection code using the java.sql package, establish connections through DriverManager.getConnection() and execute SQL operations; 4. Use connection pools (such as HikariCP), securely store credentials, use try-with-resources to automatically close resources, and properly handle exceptions to improve application performance and security; ultimately ensure that Java applications can interact with PostgreSQL stably and efficiently.
Jul 31, 2025 am 06:19 AM
Goisanexcellentchoiceforbuildinghigh-performance,reliableETLpipelinesduetoitssimplicity,concurrencysupport,andefficientdeployment.1.Gooffersperformancethroughnativecompilation,easyconcurrencyviagoroutines,staticbinariesforhassle-freedeployment,strong
Jul 31, 2025 am 06:19 AM
Use the motion component to replace HTML tags to implement declarative animations; 2. Add interactive feedback through whileHover and whileTap; 3. Use the layout attribute to automatically animate layout changes; 4. Use variants and staggerChildren to create list interleaving animations - FramerMotion makes React animations smooth and efficient, and start from the basics quickly and improve user experience.
Jul 31, 2025 am 06:18 AM
SealedclassesandinterfacesinJavaallowrestrictinginheritancetoaknownsetofsubclasses,enhancingcodesafetyandmaintainability.IntroducedinJava17,theyrequirethesealedkeywordandapermitsclauselistingallowedsubclasses—eachofwhichmustbefinal,sealed,orexplicitl
Jul 31, 2025 am 06:07 AM
Container query is the next evolution of responsive design. It enables components to adjust styles according to the parent container size rather than the viewport size, thereby achieving truly reusable context-aware components. 1. Create query containers through container-type, 2. Use @container to write conditional styles according to container size, 3. Complementary rather than substitute with media queries, 4. Applicable to scenarios such as card layout, navigation menus, etc. It is currently supported by mainstream browsers and can be used in combination with modern front-end frameworks.
Jul 31, 2025 am 06:06 AM
The key to retaining the original Host request header is to actively configure the proxy tool to ensure that the backend correctly recognizes the domain name. When using Nginx, you need to set proxy_set_headerHost$host or $http_host; Apache needs to enable ProxyPreserveHostOn; HAProxy, Envoy, Traefik and other tools also have corresponding configurations. When troubleshooting problems, you should check the CDN, intermediate agent and SNI settings, and verify whether the Host header has been modified through packet capture or tool.
Jul 31, 2025 am 06:05 AM
Cypress is a modern and efficient front-end end-to-end testing framework suitable for E2E testing. It runs directly in the browser, which is faster to respond and more convenient to debug. Before use, you need to install Node.js and npm, and then install it through the command npminstallcypress-save-dev, and the graphical interface can be started through npxcypressopen. The file structure will be automatically generated for the first time. It is recommended to write common commands into the scripts of package.json for call. When writing test cases, each file is placed under cypress/e2e, with suffixed with .cy.js or .cy.ts. A simple login test includes accessing pages, filling in forms,
Jul 31, 2025 am 05:57 AM
tRPCenablesend-to-endtypesafetyinfull-stackTypeScriptappsbyautomaticallyinferringandsharingtypesfromservertoclient.1.Defineproceduresinroutersontheserver,whereinputandreturntypesareinferredfromcodeorvalidationschemaslikeZod.2.ExposetherouterviaHTTPus
Jul 31, 2025 am 05:53 AM
To gracefully handle async/await errors in JavaScript, you must use try/catch to catch exceptions. 1. Use try/catch to wrap await expression for a single asynchronous operation and check the response status; 2. Use higher-order functions such as withErrorHandling to encapsulate duplicate error handling logic to keep the code neat; 3. Listen to unhandledrejection events to prevent uncaught Promise errors; 4. Use Promise.allSettled() instead of Promise.all() to handle multiple asynchronous operations to allow partial failure; 5. Optionally use safeAwait and other tools to return [e]
Jul 31, 2025 am 05:47 AM
Use srcset and responsive image optimization. 1. Use srcset and sizes attribute to select appropriate pictures according to the device resolution to improve loading speed; 2. Use artistic direction control, such as displaying different compositions under different screens; 3. You can combine the two to achieve resolution switching and content adjustment at the same time; 4. Always provide fallback, use WebP format first, and control the number of image versions to be within 2-3; 5. Test the effect on real devices. Correct application of these technologies can significantly improve performance and user experience, and ultimately achieve smarter image loading strategies.
Jul 31, 2025 am 05:46 AM
Using Python to automate CI/CD requires clearing the process and matching tools. 1. Trigger the CI process through Git, and use GitHubActions, GitLabCI and other tool configuration files to define the construction steps, such as running the test when submitting the code. 2. Automate the testing process, including unit testing (pytest/unittest), type check (mypy), code style check (black/flake8), and security check (bandit). 3. When deploying automation, push it to the test environment first, and use PyPI release, server deployment (Fabric/Ansible), Docker containerization, or CI tool trigger scripts to implement CDs. Through these steps
Jul 31, 2025 am 05:40 AM
Lerna is suitable for publishing multiple npm packages, focusing on version management and automated releases; 2.Nx is suitable for large teams and complex applications, providing a complete development experience, code generation and intelligent cache; 3. Turborepo is suitable for projects that pursue rapid construction and simple configuration, with performance as the core, improving CI/CD efficiency through cache and parallel tasks; the final choice should be based on specific needs: Lerna is selected for publishing, Nx is selected for structure and experience, Turborepo is selected for speed and light weight, and modern projects are often used to take into account the advantages, so the correct answer is to choose the right tool rather than a single best solution based on the question.
Jul 31, 2025 am 05:40 AM
WebWorkerspreventUIfreezingbyoffloadingheavytaskstobackgroundthreads;1.MoveCPU-intensiveoperationslikedataparsing,imageprocessing,orcomplexcalculationsintoaWebWorker;2.UsepostMessage()andonmessageforcommunicationsinceworkersruninaseparatecontextwitho
Jul 31, 2025 am 05:38 AM
LDAPprovidescentralizedauthenticationbystoringuserdataonaserverthatclientsqueryduringlogin.2.SetupanLDAPserverlikeOpenLDAPwithproperschemaanduserentries,ensuringTLSforsecurity.3.OnLinuxclients,installSSSDandconfigureittoconnecttotheLDAPserverusinglda
Jul 31, 2025 am 05:24 AM
Use the policy mode to replace the conditional logic with interchangeable behavior; 2. Use the empty object mode to eliminate null value checks; 3. Use the state mode to let the object change behavior according to the internal state; 4. Combining complex business rules through the specification mode; 5. Combining command mode and guards to achieve unconditional execution control; 6. Use class-based distribution to replace switch statements; these modes improve the maintainability, testability and scalability of the code by converting the conditional logic into polymorphism and combination, thereby building a more flexible PHP application.
Jul 31, 2025 am 05:24 AM
Learning the Yii framework is difficult, but it can be overcome through practice and community resources: 1) Beginners may feel challenges with MVC architecture and configuration files; 2) Using Gii tools can quickly generate code to help understand basic structures; 3) Advanced features such as event-driven and RESTfulAPI require more time to study; 4) Pay attention to common problems in namespace and database migration.
Jul 31, 2025 am 05:24 AM
MySQL failover automation can be implemented through Keepalived. The core is 1. Use custom scripts to monitor MySQL status, such as detecting survival and replication status through mysqladminping; 2. Configure VIP to achieve automatic drift, and the client connects VIP instead of specific hosts; 3. Switch data consistency after processing, it is recommended to enable semi-synchronous replication, add delay judgment logic, and rebuild the replication topology with other tools.
Jul 31, 2025 am 05:17 AM
Forward proxy helps clients access external resources, while reverse proxy is used for request processing in front of the server. Forward proxy initiates external requests on behalf of users, which are often used for privacy protection, bypassing restrictions or crawling; reverse proxy is located at the front end of the server, responsible for receiving client requests and forwarding them to the backend server, for load balancing, caching, SSL termination and other purposes; the core difference between the two is different directions (forward proxy faces external network, reverse proxy faces internal server), different hidden objects (forward hidden client, reverse hidden server), and different usage scenarios (the former focuses on user-side needs, while the latter focuses on server-side management). Developers usually configure reverse proxy to optimize website performance, while ordinary users use forward proxy to obtain privacy or access to restricted content.
Jul 31, 2025 am 05:04 AM
Nestedifstatementsarebetterthannestedternaryoperatorsforcomplexlogicbecausetheyaremorereadable,maintainable,andeasiertodebug;1.Useternaryoperatorsonlyforsimple,single-conditionassignments;2.Prefernullcoalescing(??)fordefaultvalues;3.Useifstatementsfo
Jul 31, 2025 am 04:59 AM
The core difference between WHERE and HAVING is the filtering timing: 1. WHERE filters rows before grouping, which are used to exclude original records that do not meet the conditions; 2. HAVING filters the aggregate results after grouping, which are used to filter groups that meet the conditions. For example, when querying active employees, use WHEREstatus='active', and when screening department users exceed 5, use HAVINGemployee_count>5; the two can also be used in combination, first reduce the amount of data through WHERE, and then filter the aggregated results through HAVING. For example, first filter full-time employees and then filter departments with an average salary of more than 60,000. Correct use of both can improve query efficiency and accuracy.
Jul 31, 2025 am 04:44 AM
PHP variables are implemented in the underlying layer through the zval structure, including metadata such as values, types, reference counts, etc., and use copy-on-write (copy on write) and reference count to optimize memory usage; 1. When the variable is assigned or passed, zval is shared instead of copying immediately, and a copy is created only when modified to reduce memory overhead; 2. Reference count tracks the number of variables pointing to zval, and the memory is immediately released when reset to zero, but circular references need to rely on periodic garbage collector cleaning; 3. Function parameters are passed by value by default, thanks to the efficient COW mechanism, and data is not copied unless modified; 4. Passing (&) to force sharing of variables, disable COW, and should be used with caution to avoid side effects; 5. Performance suggestions include: timely unset large
Jul 31, 2025 am 04:44 AM
JavaFlightRecorder(JFR)andJavaMissionControl(JMC)providedeep,low-overheadinsightsintoJavaapplicationperformance.1.JFRcollectsruntimedatalikeGCbehavior,threadactivity,CPUusage,andcustomeventswithlessthan2%overhead,writingittoa.jfrfile.2.EnableJFRatsta
Jul 31, 2025 am 04:42 AM
First make sure to allow SSH access, then enable UFW and set the default policy to deny all inbound and all outbound traffic, then open the necessary service ports (such as SSH, HTTP, HTTPS), optionally limit access to the source IP, use speed limit rules to prevent brute force cracking, and verify the configuration through ufwstatus, and finally avoid resetting the firewall.
Jul 31, 2025 am 04:39 AM
Websites run slow on IIS, which are usually related to application pool configuration, error request processing, module settings, and server resources. 1. Check the application pool settings to ensure that the recycling frequency is reasonable, the startup mode is set to AlwaysRunning, and turn on preloading; 2. Check the logs and wrong requests, locate problems such as slow SQL or frequent 404; 3. Adjust the IIS module and compression settings, disable unnecessary modules and enable dynamic content compression; 4. Monitor the use of server resources and optimize concurrent processing capabilities.
Jul 31, 2025 am 04:34 AM
useMemo and useCallback are used to solve performance problems in React due to repeated creation of values and functions, avoiding unnecessary re-rendering and expensive calculations. 2.useMemo caches expensive calculation results and is only re-executes when dependencies change. It is suitable for scenarios where calculation overhead is large, dependency changes are few, and passed to subcomponents. It is not used for simple operations or just for neat code. 3.useCallback caches function instances, keeping the reference unchanged, suitable for cases where it is passed to a child component optimized by React.memo or as a dependency on other Hooks, and is not used only locally or to a non-optimized component. 4. Common pitfalls include over-optimization and omission of dependencies in dependencies in arrays, which should be passed through E
Jul 31, 2025 am 04:18 AM
JPAprovidesastandardizedORMspecificationwhileHibernateimplementsitwithaddedfeatures.UseJPAforportabilityandHibernateforadvancedcapabilities.Entitiestransitionthroughtransient,managed,detached,andremovedstateswithinthepersistencecontext,whichensuresid
Jul 31, 2025 am 04:16 AM
WiredTiger is the only recommended choice in MongoDB's storage engine. 1. WiredTiger supports document-level concurrency, high compression ratio, Checkpoint persistence and efficient cache management, which significantly improves performance and scalability; 2. MMAPv1 is no longer applicable due to collection-level locking, no compression, OS cache dependent and has been removed in version 4.0; 3. The engine can be viewed through db.serverStatus().storageEngine. It is specified by --storageEngine or configuration file during initialization, but cannot be changed later; 4. WiredTiger should be used for new projects, production environments, and migration scenarios; 5. Tuning suggestions include setting cache
Jul 31, 2025 am 04:16 AM
Conditional types implement the "if" logic at the type level through TextendsU?X:Y, which can be used to filter union types, such as ExtractStrings to extract string types in union types; 2. Mapping types can dynamically transform object properties, such as determining whether they are optional based on the value type, or using the as clause to filter key names; 3. The infer keyword is used to extract deep types in conditional types, such as obtaining function return value or parameter type, and can also recursively unpack Promise; 4. Recursive types such as DeepPartial support optional properties of nested objects, which are suitable for configuration updates and other scenarios; 5. Conditional types are distributed by default for union types, and can be packaged by wrapping tuples [T]extends
Jul 31, 2025 am 04:15 AM
