Examples of implementing dynamic proxies with spring AOP

Let me show you examples of implementing dynamic proxies with spring AOP (computer printing)

Here's a look at the specific code:

Define the interface of a printer first

1  Package Aop007_comprint; 2 3  Public Interface Print {4     5      Public void Colorprint ();    // Color Printing 6      Public void Whiteprint ();    // Black and white printing 7 }

Then define two implementation classes for color printing and black-and-white printing, respectively

1  PackageAop007_comprint;2 3  Public classColorprintImplementsPrint {4 5 @Override6      Public voidColorprint () {7System.out.println ("[core business logic] I am a color printer! ");8System.out.println ("[core business logic] I am mainly responsible for printing color information!" ");9     }Ten  One @Override A      Public voidWhiteprint () { -         //System.out.println ("[core business logic] I am mainly responsible for printing black and white materials!" "); -     } the  -}

1  PackageAop007_comprint;2 3  Public classWhiteprintImplementsPrint {4 5 @Override6      Public voidWhiteprint () {7System.out.println ("[core business logic] I am a black and white printer! ");8System.out.println ("[core business logic] I am mainly responsible for printing black and white materials!" ");9     }Ten      One @Override A      Public voidColorprint () { -         //System.out.println ("[core business logic] I am mainly responsible for printing color information!" "); -     } the  -}

Define a proxy class Printhandler implement dynamic Agent printing function

1  PackageAop007_comprint;2 3 ImportJava.lang.reflect.InvocationHandler;4 ImportJava.lang.reflect.Method;5 Importjava.util.Date;6 7  Public classPrinthandlerImplementsInvocationhandler {8     //target type is not deterministic9     PrivateObject Target;Ten      PublicPrinthandler (Object target) { One          This. target =Target; A     } -     /* - * Return returns the content returned by the original target method is the method to be executed the      */ - @Override -      PublicObject Invoke (Object proxy, Method method, object[] args)throwsThrowable { - before (); +          -         //Specific business logic code +         //Object returnprintobj = Targer.method//used to interpret the following line of code AObject returnprintobj =Method.invoke (target, args); at          - After (); -         returnreturnprintobj; -     } -      -     Private voidbefore () { in         //predecessor Task -System.out.println (NewDate ()); toSYSTEM.OUT.PRINTLN ("printer"); +System.out.println ("Southern It Academy offers!") "); -     } the      *     Private voidAfter () { $         //Post TaskPanax NotoginsengSystem.out.println ("College Printer"); -System.out.println ("Please take good care, broken you can afford!!! "); the     } +  A}

Finally, define a test class Testprint function for testing printing

1  PackageAop007_comprint;2 3 ImportJava.lang.reflect.InvocationHandler;4 ImportJava.lang.reflect.Proxy;5 6 /*7 * Add a "Dynamic proxy class", similar to a star broker8 * Separating the code of the core business logic from the non-core9 * Give the non-core code to the broker to manage,Ten * Note: Brokers and want stars must implement the same interface One  */ A  Public classTestprint { -  -      Public Static voidMain (string[] args) { the         //First step: Create an instance of the target implementation class -Print Cprint =Newcolorprint (); -Print Wprint =Newwhiteprint (); -          +         //Step Two: Create a dynamic proxy class (CEO) -Invocationhandler Cprinthandler =NewPrinthandler (cprint); +Invocationhandler Wprinthandler =NewPrinthandler (wprint); A          at         //Step Three: Create a dynamic proxy (like a static proxy, the declared variable is still the target's interface) -Print Cprintproxy =(Print) proxy.newproxyinstance (Cprint.getclass (). getClassLoader (), - Cprint.getclass (). Getinterfaces (), - Cprinthandler); -Print Wprintproxy =(Print) proxy.newproxyinstance (Wprint.getclass (). getClassLoader (), - Wprint.getclass (). Getinterfaces (), in Wprinthandler); -          toCprintproxy.colorprint ();//contrast cprint.colorprint (); [Core code only] after running the difference +System.out.println ("------------------------------"); -Wprintproxy.whiteprint ();//contrast wprint.whiteprint (); [Core code only] after running the difference the     } *  $}

This is the end of the run, and the result is as follows:

Examples of implementing dynamic proxies with spring AOP