2020 New Java Interview Questions - Network (2)
Jun 20, 2020 pm 05:32 PM#1. What are the seven-layer models of OSI?
Application layer: An interface between network services and end users.
(Recommended tutorial: java interview questions)
Presentation layer: data representation, security, and compression.
Session layer: establish, manage, and terminate sessions.
Transport layer: Define the protocol port number for transmitting data, as well as flow control and error checking.
Network layer: Perform logical address addressing to realize path selection between different networks.
Data link layer: Establish logical connections, perform hardware address addressing, error checking and other functions.
Physical layer: establishing, maintaining, and disconnecting physical connections.
2. What are the differences between get and post requests?
GET is harmless when the browser rolls back, while POST will submit the request again.
The URL address generated by GET can be Bookmarked, but POST cannot.
GET requests will be actively cached by the browser, but POST will not unless manually set.
GET requests can only be URL encoded, while POST supports multiple encoding methods.
GET request parameters will be completely retained in the browser history, while parameters in POST will not be retained.
There is a length limit on the parameters transmitted in the URL for the GET request, but there is no length limit for POST.
Regarding the data type of parameters, GET only accepts ASCII characters, while POST has no restrictions.
GET is less secure than POST because the parameters are directly exposed on the URL, so it cannot be used to pass sensitive information.
GET parameters are passed through the URL, and POST is placed in the Request body.
3. How to achieve cross-domain?
Method 1: Image ping or script tag cross-domain
Method 2: JSONP cross-domain
Method 3: CORS
Method 4: window.name iframe
Method 5: window.postMessage()
Method 6: Modify document.domain across subdomains
Method 7: WebSocket
Method 8: Proxy
4. Tell me about the JSONP implementation principle?
jsonp is json padding, which dynamically creates script tags. Using the src attribute of the script tag, you can obtain js scripts in any domain. Through this feature (it can also be said to be a loophole), the server no longer returns json. format, but returns a piece of js code that calls a certain function, and calls it in src, thus achieving cross-domain.
The above is the detailed content of 2020 New Java Interview Questions - Network (2). For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

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.

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

Pre-formanceTartuptimeMoryusage, Quarkusandmicronautleadduetocompile-Timeprocessingandgraalvsupport, Withquarkusoftenperforminglightbetterine ServerLess scenarios.2.Thyvelopecosyste,

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

Java's garbage collection (GC) is a mechanism that automatically manages memory, which reduces the risk of memory leakage by reclaiming unreachable objects. 1.GC judges the accessibility of the object from the root object (such as stack variables, active threads, static fields, etc.), and unreachable objects are marked as garbage. 2. Based on the mark-clearing algorithm, mark all reachable objects and clear unmarked objects. 3. Adopt a generational collection strategy: the new generation (Eden, S0, S1) frequently executes MinorGC; the elderly performs less but takes longer to perform MajorGC; Metaspace stores class metadata. 4. JVM provides a variety of GC devices: SerialGC is suitable for small applications; ParallelGC improves throughput; CMS reduces

TosharefilesonWindows,enablenetworkdiscoveryandfilesharinginAdvancedSharingSettings,shareafolderbysettingpermissionsforusersoreveryone,andaccessitfromanotherPCviaNetworkor\\ComputerNameinFileExplorer.2.OnmacOS,enableFileSharinginSystemSettings,addfol

Gradleisthebetterchoiceformostnewprojectsduetoitssuperiorflexibility,performance,andmoderntoolingsupport.1.Gradle’sGroovy/KotlinDSLismoreconciseandexpressivethanMaven’sverboseXML.2.GradleoutperformsMaveninbuildspeedwithincrementalcompilation,buildcac

defer is used to perform specified operations before the function returns, such as cleaning resources; parameters are evaluated immediately when defer, and the functions are executed in the order of last-in-first-out (LIFO); 1. Multiple defers are executed in reverse order of declarations; 2. Commonly used for secure cleaning such as file closing; 3. The named return value can be modified; 4. It will be executed even if panic occurs, suitable for recovery; 5. Avoid abuse of defer in loops to prevent resource leakage; correct use can improve code security and readability.
