The settings.json file is located in the user-level or workspace-level path and is used to customize VSCode settings. 1. User-level path: Windows is C:\Users\\AppData\Roaming\Code\User\settings.json, macOS is /Users//Library/ApplicationSupport/Code/User/settings.json, Linux is /home//.config/Code/User/settings.json; 2. Workspace-level path: .vscode/settings in the project root directory

To correctly handle JDBC transactions, you must first turn off the automatic commit mode, then perform multiple operations, and finally commit or rollback according to the results; 1. Call conn.setAutoCommit(false) to start the transaction; 2. Execute multiple SQL operations, such as INSERT and UPDATE; 3. Call conn.commit() if all operations are successful, and call conn.rollback() if an exception occurs to ensure data consistency; at the same time, try-with-resources should be used to manage resources, properly handle exceptions and close connections to avoid connection leakage; in addition, it is recommended to use connection pools and set save points to achieve partial rollback, and keep transactions as short as possible to improve performance.

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

TheJVMenablesJava’s"writeonce,runanywhere"capabilitybyexecutingbytecodethroughfourmaincomponents:1.TheClassLoaderSubsystemloads,links,andinitializes.classfilesusingbootstrap,extension,andapplicationclassloaders,ensuringsecureandlazyclassloa

Use classes in the java.time package to replace the old Date and Calendar classes; 2. Get the current date and time through LocalDate, LocalDateTime and LocalTime; 3. Create a specific date and time using the of() method; 4. Use the plus/minus method to immutably increase and decrease the time; 5. Use ZonedDateTime and ZoneId to process the time zone; 6. Format and parse date strings through DateTimeFormatter; 7. Use Instant to be compatible with the old date types when necessary; date processing in modern Java should give priority to using java.timeAPI, which provides clear, immutable and linear

PaymentHandlerAPI is part of the WebPayments standard, as an extension of PaymentRequestAPI, and its core role is to allow developers to register a "payment processor" to implement custom payment processes. It registers payment methods through ServiceWorker and combines the payment application manifest file under the .well-known directory to declare payment processor information. When used, the payment request is initiated through the PaymentRequest interface, the registered payment processor is called, and the complete() method is called after the payment is completed. Common precautions include: 1. Ensure HTTPS deployment; 2. Properly configure Service

ChromecanopenlocalfileslikeHTMLandPDFsbyusing"Openfile"ordraggingthemintothebrowser;ensuretheaddressstartswithfile:///;2.SecurityrestrictionsblockAJAX,localStorage,andcross-folderaccessonfile://;usealocalserverlikepython-mhttp.server8000tor

Networkportsandfirewallsworktogethertoenablecommunicationwhileensuringsecurity.1.Networkportsarevirtualendpointsnumbered0–65535,withwell-knownportslike80(HTTP),443(HTTPS),22(SSH),and25(SMTP)identifyingspecificservices.2.PortsoperateoverTCP(reliable,c