Java design Pattern (v) Responsibility chain model

Many objects have a link to each object's reference to its next generation, and the request is passed through the chain until an object on the chain decides to process the request, such as a scenario such as a unit approval process.

Key points: 1) abstract processor role: Define processing request interface and set a referral

2) Specific handling of the role: specific processing requests or choose to pass the request to the

1. Abstract processor role class, define processing request interface and reference

 Public Abstract classPricehandle {protectedPricehandle successor;  Public voidSetsuccessor (Pricehandle successor) { This. successor =successor; }     Public Abstract voidProcessfloatdiscount);  Public StaticPricehandle Createpricehandle () {Pricehandle sales=NewSales (); Pricehandle Direct=NewDirect (); Pricehandle CEO=NewCEO ();        Sales.setsuccessor (direct);        Direct.setsuccessor (CEO); returnsales; }}

2. Specific processor role Category sales category

 Public class extends Pricehandle {    publicvoid process (float  discount) {        if (Discount <= 0.1) {            System.out.format ("%s approved discount:%.2f%n", this. GetClass (). GetName (), discount);         Else {            successor.process (discount);     }}}

3. Specific Processor Role Supervisor class

 Public class extends Pricehandle {    publicvoid process (float  discount) {        if (Discount <= 0.2) {            System.out.format ("%s approved discount:%.2f%n", this. GetClass (). GetName (), discount);         Else {            successor.process (discount);     }}}

4. Specific Processor Role CEO category

 Public class extends Pricehandle {    publicvoid process (float  discount) {        if (Discount <= 0.3) {            System.out.format ("%s approved discount:%.2f%n", this. GetClass (). GetName (), discount);         Else {            System.out.format ("%s declined discount:%.2f%n", this. GetClass (). GetName (), discount);}    } }

5. Test class

 Public classModel {PrivatePricehandle Pricehandle;  Public voidSetpricehandle (Pricehandle pricehandle) { This. Pricehandle =Pricehandle; }     Public voidRequestdiscount (floatdiscount)    {pricehandle.process (discount); }     Public Static voidMain (string[] args) {Model customer=NewModel ();        Customer.setpricehandle (Pricehandle.createpricehandle ()); Random Random=NewRandom ();  for(inti = 0; I < 100; i++) {System.out.print (i+ ":");        Customer.requestdiscount (Random.nextfloat ()); }    }}

Java design Pattern (v) Responsibility chain model