What is the proxy mode
Definition of proxy mode: For some reasons, it is necessary to provide a proxy for an object to control access to the object. At this time, the access object is not suitable or cannot directly reference the target object, and the proxy object acts as an intermediary between the access object and the target object.
Advantages
1. The proxy mode plays an intermediary role between the client and the target object and protects the target object;
2. The proxy object can expand the target The function of the object;
3. The proxy mode can separate the client from the target object, which reduces the coupling of the system to a certain extent and increases the scalability of the program
Disadvantages
1. The proxy mode will increase the number of classes in the system design
2. Adding a proxy object between the client and the target object will cause the request processing speed to slow down;
3. Increases the complexity of the system;
Knowledge points
The structure of the agent mode is relatively simple, mainly by defining an agent that inherits the abstract topic to include the real topic, thereby realizing the To access real topics, let’s analyze its basic structure and implementation methods.
Agency model implementation
Case: Da Ben Dai Ganniang sells wine
Abstract subject (Subject) class: selling wine
Real Subject ) Category: Godmother’s tavern
Proxy Category: Da Ben’s wine stall
Da Ben came to set up a stall in front of Godmother’s tavern to sell wine as a proxy.
selling wine
A wine-selling interface declares an abstract method for selling wine
public interface Jiu { void show(); }
Godmother’s tavern
Godmother’s tavern class implementation Developed an interface for selling wine, implemented the show() wine selling method, declared a wine name, and an aa() method to prompt Da Ben to set up a stall
public class GanNiang implements Jiu { private String name; GanNiang() { } GanNiang(String name) { this.name = name; aa(); } @Override public void show() { System.out.printf("卖出一坛%s", name); } public void aa() { System.out.println("大奔来摆摊了"); } }
Da Ben’s wine stall
Daben’s wine stall class implements the wine selling interface, declares the name of the wine and the attributes of Ganniang Tavern, and implements the wine selling method.
public class DaBen implements Jiu { private String name; private GanNiang ganNiang; DaBen() { } DaBen(String name) { this.name = name; } @Override public void show() { if (ganNiang == null) { ganNiang = new GanNiang(name); } ganNiang.show(); } }
Test
new A big wine stall, calling the show() method twice is equivalent to selling wine twice.
public class Demo { public static void main(String[] args) { DaBen daBen = new DaBen("女儿红"); daBen.show(); System.out.println(); System.out.println(); daBen.show(); } }
It can be seen here that the output results of the first time selling wine and the second time selling wine are different, because every time you sell wine, you have to go to the godmother’s tavern to get it. liquor. When Da Ben came to get the wine for the first time, he informed his godmother that I was here to set up the stall. Later, the godmother already knew that Da Ben was coming, so there was no need to notify him when he got the wine again.
The above is the detailed content of How to implement the proxy pattern in Java design patterns. For more information, please follow other related articles on the PHP Chinese website!

JVMmanagesgarbagecollectionacrossplatformseffectivelybyusingagenerationalapproachandadaptingtoOSandhardwaredifferences.ItemploysvariouscollectorslikeSerial,Parallel,CMS,andG1,eachsuitedfordifferentscenarios.Performancecanbetunedwithflagslike-XX:NewRa

Java code can run on different operating systems without modification, because Java's "write once, run everywhere" philosophy is implemented by Java virtual machine (JVM). As the intermediary between the compiled Java bytecode and the operating system, the JVM translates the bytecode into specific machine instructions to ensure that the program can run independently on any platform with JVM installed.

The compilation and execution of Java programs achieve platform independence through bytecode and JVM. 1) Write Java source code and compile it into bytecode. 2) Use JVM to execute bytecode on any platform to ensure the code runs across platforms.

Java performance is closely related to hardware architecture, and understanding this relationship can significantly improve programming capabilities. 1) The JVM converts Java bytecode into machine instructions through JIT compilation, which is affected by the CPU architecture. 2) Memory management and garbage collection are affected by RAM and memory bus speed. 3) Cache and branch prediction optimize Java code execution. 4) Multi-threading and parallel processing improve performance on multi-core systems.

Using native libraries will destroy Java's platform independence, because these libraries need to be compiled separately for each operating system. 1) The native library interacts with Java through JNI, providing functions that cannot be directly implemented by Java. 2) Using native libraries increases project complexity and requires managing library files for different platforms. 3) Although native libraries can improve performance, they should be used with caution and conducted cross-platform testing.

JVM handles operating system API differences through JavaNativeInterface (JNI) and Java standard library: 1. JNI allows Java code to call local code and directly interact with the operating system API. 2. The Java standard library provides a unified API, which is internally mapped to different operating system APIs to ensure that the code runs across platforms.

modularitydoesnotdirectlyaffectJava'splatformindependence.Java'splatformindependenceismaintainedbytheJVM,butmodularityinfluencesapplicationstructureandmanagement,indirectlyimpactingplatformindependence.1)Deploymentanddistributionbecomemoreefficientwi

BytecodeinJavaistheintermediaterepresentationthatenablesplatformindependence.1)Javacodeiscompiledintobytecodestoredin.classfiles.2)TheJVMinterpretsorcompilesthisbytecodeintomachinecodeatruntime,allowingthesamebytecodetorunonanydevicewithaJVM,thusfulf


Hot AI Tools

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

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

Undress AI Tool
Undress images for free

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

SublimeText3 English version
Recommended: Win version, supports code prompts!

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 Chinese version
Chinese version, very easy to use

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
