The technical principles of Backport of JSR 166 in the Java class library

Backport of JSR 166 (disassembly of JSR 166) introduce JSR 166 is a standard library of multi -threaded programming.However, because some Java versions do not support the standard, the JSR 166 needs to be disassembled and the function is migrated to the old version of the Java library.This migration process is called the backward transplant of the JSR 166. Principles of disassembly technology JSR 166 requires developers to use some technical means to transplant personnel to achieve its functions in the old version of the Java library.The following is some common technical principles for transplantation after implementation: 1. Adapter mode: By writing the adapter class, the class and methods of the JSR 166 are connected with the old version of the Java library.The adapter class converts the function of the JSR 166 into an old version of the Java class library to understand the corresponding functions. 2. Custom implementation: If the adapter mode cannot be connected to the old version of the Java class library well, developers can implement the functions of JSR 166 by themselves.By understanding the principles and requirements of JSR 166, developers can write similar functional code to provide similar multi -threaded functions in the old version of the Java library. 3. Reflection: Reflection is a mechanism and attribute mechanism that dynamics to obtain and use class when runtime.In the rear transplantation of the JSR 166, developers can use reflexes to call the method in the old version of the Java library, and encapsulate it into the JSR 166 interface to achieve the purpose of the transplantation after the transplantation. 4. Class library packaging: encapsulate the classes and methods in JSR 166 into an old version of the Java class library, so that it can be used directly in the old version of Java.By packaging, developers can hide their direct dependence on JSR 166, so that they can work smoother in the old version of Java. Exemplary example Below is a simple example, showing how to achieve the rear transplantation of the JSR 166 through the adapter mode: // The class in JSR 166 import java.util.concurrent.LinkedBlockingQueue; // adapter class public class BackportQueue<T> { private LinkedBlockingQueue<T> queue; public BackportQueue() { this.queue = new LinkedBlockingQueue<T>(); } public void add(T element) { queue.add(element); } public T remove() { return queue.remove(); } } // The use of the old version of the Java library public class Main { public static void main(String[] args) { BackportQueue<Integer> queue = new BackportQueue<Integer>(); queue.add(1); queue.add(2); queue.add(3); System.out.println (queue.remove ()); // Output: 1 System.out.println (queue.remove ()); // Output: 2 System.out.println (queue.remove ()); // Output: 3 } } In the above code, we created an adapter for the `Backportqueue" class as the `LinkedBlockingQueue` of JSR 166.The adapter class provides a method similar to `java.util.queueme`, but it uses the JSR 166 class implementation inside.In the main program, we tested the adapter class to show the rear transplantation of the JSR 166 function in the old version of the Java library. Summarize By disassembling the technical principle, migrating the function of JSR 166 into the old version of the Java library can enable the Java environment that does not support the JSR 166 can also enjoy the convenience of multi -threaded programming.Developers can use technical means such as adapter mode, custom implementation, reflection and other technical means to transplant.This disassembly technology provides developers with greater flexibility and diversity, so that they can choose the appropriate way to achieve the JSR 166 backward transplantation according to actual needs.