Design pattern Start--responsibility chain mode

The pattern of the responsibility chain

First, the role

Multiple objects have the opportunity to process the request, avoiding the coupling between the sender and the recipient of the request, connecting the object to a chain, and passing the request along the chain until an object can handle it

Second, class diagram

Third, the realization

(1) Definition handle

 Public Abstract classHandle {protectedHandle successor;  Public voidSetseccessor (Handle successor) { This. successor =successor; }     Public Abstract voidHandleRequest (intrequest);} Public classConcretehandleoneextendsHandle {@Override Public voidHandleRequest (intrequest) {        if(Request >= 0 && Request < 10) {System.out.println ("One processing request" +request); }        Else if(Successor! =NULL) {successor.handlerequest (request); }    }} Public classConcretehandletwoextendsHandle {@Override Public voidHandleRequest (intrequest) {        if(Request >= && Request < 20) {System.out.println ("Processing Request" +request); }        Else if(Successor! =NULL) {successor.handlerequest (request); }    }} Public classConcretehandlethreeextendsHandle {@Override Public voidHandleRequest (intrequest) {        if(Request > 20) {System.out.println ("Three processing request" +request); }        Else if(Successor! =NULL) {successor.handlerequest (request); }    }}

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(2) Client Test class

 public  class   Client { public  static  void   main (string[] args) {Handle        H1  = new   Concretehandleone ();        Handle H2  =  Concretehandletwo ();        Handle h3  =  Concretehandlethree ();        H1.successor  = H2;        H2.successor  = H3;         int  request = 14

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Design pattern Start--responsibility chain mode