spring源代碼解析十一

Spring源代碼解析(十)：SpringAcegi框架授權的實現(xiàn)2009-08-11(周二)11:04SpringSpring被圍觀一共有280個打醬油的路過+我們從FilterSecuritylnterceptor我們從入手看看怎樣進行授權的：如轉(zhuǎn)載請注明，轉(zhuǎn)載自： [ /r/本文鏈接:/2009/08/11/231-htmlJava代碼〃這里是攔截器攔截HTTP請求的入口publicvoiddoFilter(ServletRequestrequest,ServletResponseresponse,FilterChainchain)throwslOException,ServletException{Filterinvocationfi=newFilterlnvocation(request,response,chain);invoke(fi);}〃這是具體的攔截調(diào)用publicvoidinvoke(Filterlnvocationfi)throwsIOException,ServletException{if((fi.getRequest()!=null)&&(fi.getRequest().getAttribute(FILTER_APPLIED)!=nuII)&&observeOncePerRequest){〃在第一次進行過安全檢查之后就不會再做了fi.getChain().doFilter(fi.getRequest(),fi.getResponse());}else{〃這是第一次收到相應的請求，需要做安全檢測，同時把標志為設置好-FILTER_APPLIED,下次就再有請求就不會作相同的安全檢查了if(fi.getRequest()!=null){fi.getRequest().setAttribute(FILTER_APPLIED,Boolean.TRUE);}〃這里是做安全檢查的地方InterceptorStatusTokentoken=super.beforelnvocation(fi);〃接著向攔截器鏈執(zhí)行try{fi.getChain().doFilter(fi.getRequest(),fi.getResponse());}finally{super.afterlnvocation(token,null);}}}Java代碼〃這里是攔截器攔截HTTP請求的入口publicvoiddoFilter(ServletRequestrequest,ServletResponseresponse,FilterChainchain)throwslOException,ServletException{FilterInvocationfi=newFilterInvocation(request,response,chain);invoke(fi);}〃這是具體的攔截調(diào)用publicvoidinvoke(FilterInvocationfi)throwsIOException,ServletException{if((fi.getRequest()!=null)&&(fi.getRequest().getAttribute(FILTER_APPLIED)!=nuII)&&observeOncePerRequest){〃在第一次進行過安全檢查之后就不會再做了fi.getChain().doFilter(fi.getRequest(),fi.getResponse());}else{〃這是第一次收到相應的請求，需要做安全檢測，同時把標志為設置好-FILTER_APPLIED,下次就再有請求就不會作相同的安全檢查了if(fi.getRequest()!=null){fi.getRequest().setAttribute(FILTER_APPLIED,Boolean.TRUE);}〃這里是做安全檢查的地方InterceptorStatusTokentoken=super.beforeInvocation(fi);〃接著向攔截器鏈執(zhí)行try{fi.getChain().doFilter(fi.getRequest(),fi.getResponse());}finally{super.afterlnvocation(token,null);}}}我們看看在AbstractSecurityInterceptor是怎樣對HTTP請求作安全檢測的：Java代碼protectedlnterceptorStatusTokenbeforelnvocation(Objectobject){Assert.notNull(object,"Objectwasnull");3.if(!getSecureObjectClass().isAssignableFrom(object.getClass())){thrownewIllegalArgumentException("Securityinvocationattemptedforobject"+object.getClass().getName()+"butAbstractSecuritylnterceptoronlyconfiguredtosupportsecureobjectsoftype:"+getSecureObjectClass());}〃這里讀取配置FilterSecuritylnterceptor的ObjectDefinitionSource屬性，這些屬性配置了資源的安全設置ConfigAttributeDefinitionattr=this.obtainObjectDefinitionSource().getAttributes(object);12.if(attr==null){if(rejectPubliclnvocations){thrownewlllegalArgumentException("NopublicinvocationsareallowedviathisAbstractSecurityInterceptor."+"Thisindicatesaconfigurationerrorbecausethe"+"AbstractSecurityInterceptor.rejectPublicInvocationspropertyissetto'true'");}20.if(logger.isDebugEnabled()){logger.debug("Publicobject-authenticationnotattempted");}24.publishEvent(newPubliclnvocationEvent(object));26.returnnull;//nofurtherworkpost-invocation}29.30.if(logger.isDebugEnabled()){logger.debug("Secureobject:"+object.toString()+";ConfigAttributes:"+attr.toString());}〃這里從SecurityContextHolder中去取Authentication對象，一般在登錄時會放到SecurityContextHolder中去if(SecurityContextHolder.getContext().getAuthentication()==null){credentialsNotFound(messages.getMessage("AbstractSecuritylnterceptor.authenticationNotFound","AnAuthenticationobjectwasnotfoundintheSecurityContext"),object,attr);}39.//如果前面沒有處理鑒權，這里需要對鑒權進行處理Authenticationauthenticated;42.if(!SecurityContextHolder.getContext().getAuthentication().isAuthenticated()||alwaysReauthenticate){try{//調(diào)用配置好的AuthenticationManager處理鑒權，如果鑒權不成功，拋出異常結束處理authenticated=this.authenticationManager.authenticate(SecurityContextHolder.getContext().getAuthentication());}catch(AuthenticationExceptionauthenticationException){throwauthenticationException;}50.//Wedon'tauthenticated.setAuthentication(true),becauseeachprovidershoulddothatif(logger.isDebugEnabled()){logger.debug("SuccessfullyAuthenticated:"+authenticated.toString());}〃這里把鑒權成功后得到的Authentication保存到SecurityContextHolder中供下次使用SecurityContextHolder.getContext().setAuthentication(authenticated);}else{//這里處理前面已經(jīng)通過鑒權的請求，先從SecurityContextHolder中去取得Authenticationauthenticated=SecurityContextHolder.getContext().getAuthentication();59.if(logger.isDebugEnabled()){logger.debug("PreviouslyAuthenticated:"+authenticated.toString());}}64.//這是處理授權的過程try{〃調(diào)用配置好的AccessDecisionManager來進行授權this.accessDecisionManager.decide(authenticated,object,attr);}catch(AccessDeniedExceptionaccessDeniedException){〃授權不成功向外發(fā)布事件AuthorizationFailureEventevent=newAuthorizationFailureEvent(object,attr,authenticated,accessDeniedException);publishEvent(event);74.throwaccessDeniedException;}77.if(logger.isDebugEnabled()){logger.debug("Authorizationsuccessful");}AuthorizedEventevent=newAuthorizedEvent(object,attr,authenticated);publishEvent(event);84.//這里構建一個RunAsManager來替代當前的Authentication對象，默認情況下使用的是NullRunAsManager會把SecurityContextHolder中的Authentication對象清空AuthenticationrunAs=this.runAsManager.buildRunAs(authenticated,object,attr);87.if(runAs==null){if(logger.isDebugEnabled()){logger.debug("RunAsManagerdidnotchangeAuthenticationobject");}92.//nofurtherworkpost-invocationreturnnewlnterceptorStatusToken(authenticated,false,attr,object);}else{if(logger.isDebugEnabled()){logger.debug("SwitchingtoRunAsAuthentication:"+runAs.toString());}99.SecurityContextHolder.getContext().setAuthentication(runAs);101.//reverttotoken.Authenticatedpost-invocationreturnnewlnterceptorStatusToken(authenticated, true,attr,object);}Java代碼Java代碼protectedInterceptorStatusTokenbeforelnvocation(Objectobject){Assert.notNull(object,"Objectwasnull");3.if(!getSecureObjectClass().isAssignableFrom(object.getClass())){thrownewlllegalArgumentException("Securityinvocationattemptedforobject"+object.getClass().getName()+"butAbstractSecurityInterceptoronlyconfiguredtosupportsecureobjectsoftype:"+getSecureObjectClass());}〃這里讀取配置FilterSecurityInterceptor的ObjectDefinitionSource屬性，這些屬性配置了資源的安全設置ConfigAttributeDefinitionattr=this.obtainObjectDefinitionSource().getAttributes(object);12.if(attr==null){if(rejectPublicInvocations){thrownewlllegalArgumentException("NopublicinvocationsareallowedviathisAbstractSecuritylnterceptor."+"Thisindicatesaconfigurationerrorbecausethe"+"AbstractSecuritylnterceptor.rejectPublicInvocationspropertyissetto'true'");}20.if(logger.isDebugEnabled()){logger.debug("Publicobject-authenticationnotattempted");}24.publishEvent(newPubliclnvocationEvent(object));26.returnnull;//nofurtherworkpost-invocation}29.30.if(logger.isDebugEnabled()){logger.debug("Secureobject:"+object.toString()+";ConfigAttributes:"+attr.toString());}〃這里從SecurityContextHolder中去取Authentication對象，一般在登錄時會放到SecurityContextHolder中去if(SecurityContextHolder.getContext().getAuthentication()==null){credentialsNotFound(messages.getMessage("AbstractSecuritylnterceptor.authenticationNotFound","AnAuthenticationobjectwasnotfoundintheSecurityContext"),object,attr);}39.//如果前面沒有處理鑒權，這里需要對鑒權進行處理Authenticationauthenticated;42.if(!SecurityContextHolder.getContext().getAuthentication().isAuthenticated()||alwaysReauthenticate){try{//調(diào)用配置好的AuthenticationManager處理鑒權，如果鑒權不成功，拋出異常結束處理authenticated=this.authenticationManager.authenticate(SecurityContextHolder.getContext().getAuthentication());}catch(AuthenticationExceptionauthenticationException){throwauthenticationException;}50.//Wedon'tauthenticated.setAuthentication(true),becauseeachprovidershoulddothatif(logger.isDebugEnabled()){logger.debug("SuccessfullyAuthenticated:"+authenticated.toString());}〃這里把鑒權成功后得到的Authentication保存到SecurityContextHolder中供下次使用SecurityContextHolder.getContext().setAuthentication(authenticated);}else{//這里處理前面已經(jīng)通過鑒權的請求，先從SecurityContextHolder中去取得Authenticationauthenticated=SecurityContextHolder.getContext().getAuthentication();59.if(logger.isDebugEnabled()){logger.debug("PreviouslyAuthenticated:"+authenticated.toString());}}64.//這是處理授權的過程try{〃調(diào)用配置好的AccessDecisionManager來進行授權this.accessDecisionManager.decide(authenticated,object,attr);}catch(AccessDeniedExceptionaccessDeniedException){〃授權不成功向外發(fā)布事件AuthorizationFailureEventevent=newAuthorizationFailureEvent(object,attr,authenticated,accessDeniedException);publishEvent(event);74.throwaccessDeniedException;}77.if(logger.isDebugEnabled()){logger.debug("Authorizationsuccessful");}81.AuthorizedEventevent=newAuthorizedEvent(object,attr,authenticated);publishEvent(event);84.//這里構建一個RunAsManager來替代當前的Authentication對象，默認情況下使用的是NullRunAsManager會把SecurityContextHolder中的Authentication對象清空AuthenticationrunAs=this.runAsManager.buildRunAs(authenticated,object,attr);87.if(runAs==null){if(logger.isDebugEnabled()){logger.debug("RunAsManagerdidnotchangeAuthenticationobject");}92.//nofurtherworkpost-invocationreturnnewlnterceptorStatusToken(authenticated,false,attr,object);}else{if(logger.isDebugEnabled()){logger.debug("SwitchingtoRunAsAuthentication:"+runAs.toString());}99.SecurityContextHolder.getContext().setAuthentication(runAs);101.//reverttotoken.Authenticatedpost-invocationreturnnewlnterceptorStatusToken(authenticated, true, attr,object);}}到這里我們假設配置AffirmativeBased作為AccessDecisionManager:Java代碼〃這里定義了決策機制，需要全票才能通過publicvoiddecide(Authenticationauthentication,Objectobject,ConfigAttributeDefinitionconfig)throwsAccessDeniedException{〃這里取得配置好的迭代器集合Iteratoriter=this.getDecisionVoters().iterator();intdeny=0;〃依次使用各個投票器進行投票，并對投票結果進行計票while(iter.hasNext()){AccessDecisionVotervoter=(AccessDecisionVoter)iter.next();intresult=voter.vote(authentication,object,config);〃這是對投票結果進行處理，如果遇到其中一票通過，那就授權通過，如果是棄權或者反對,那就繼續(xù)投票switch(result){caseAccessDecisionVoter.ACCESS_GRANTED:return;15.caseAccessDecisionVoter.ACCESS_DENIED:〃這里對反對票進行計數(shù)deny++;19.break;21.default:break;}}〃如果有反對票，拋出異常，整個授權不通過

if(deny>0){thrownewAccessDeniedException(messages.getMessage("AbstractAccessDecisionManager.accessDenied","Accessisdenied"));}31.//這里對棄權票進行處理，看看是全是棄權票的決定情況，默認是不通過，由allowlfAIIAbstainDecisions變量控制checkAllowlfAIIAbstainDecisions();}具體的投票由投票器進行，我們這里配置了RoleVoter來進行投票：publicintvote(Authenticationauthentication,Objectobject,ConfigAttributeDefinitionconfig){intresult=ACCESS_ABSTAIN;〃這里取得資源的安全配置Iteratoriter=config.getConfigAttributes();40.while(iter.hasNext()){ConfigAttributeattribute=(ConfigAttribute)iter.next();43.if(this.supports(attribute)){result=ACCESS_DENIED;46.//這里對資源配置的安全授權級別進行判斷，也就是匹配ROLE為前綴的角色配置//遍歷每個配置屬性，如果其中一個匹配該主體持有的GrantedAuthority,則訪問被允許。for(inti=0;i<authentication.getAuthorities().length;i++){if(attribute.getAttribute().equals(authentication.getAuthorities()[i].getAuthority())){returnACCESS_GRANTED;TOC\o"1-5"\h\z}}}}56.returnresult;Java代碼}Java代碼〃這里定義了決策機制，需要全票才能通過publicvoiddecide(Authenticationauthentication,Objectobject,ConfigAttributeDefinitionconfig)throwsAccessDeniedException{〃這里取得配置好的迭代器集合Iteratoriter=this.getDecisionVoters().iterator();intdeny=0;〃依次使用各個投票器進行投票，并對投票結果進行計票while(iter.hasNext()){AccessDecisionVotervoter=(AccessDecisionVoter)iter.next();intresult=voter.vote(authentication,object,config);〃這是對投票結果進行處理，如果遇到其中一票通過，那就授權通過，如果是棄權或者反對,那就繼續(xù)投票switch(result){caseAccessDecisionVoter.ACCESS_GRANTED:return;15.caseAccessDecisionVoter.ACCESS_DENIED:〃這里對反對票進行計數(shù)deny++;19.break;21.default:break;}}〃如果有反對票，拋出異常，整個授權不通過if(deny>0){thrownewAccessDeniedException(messages.getMessage("AbstractAccessDecisionManager.accessDenied","Accessisdenied"));}31.//這里對棄權票進行處理，看看是全是棄權票的決定情況，默認是不通過，由allowIfAIIAbstainDecisions變量控制checkAllowlfAIIAbstainDecisions();}具體的投票由投票器進行，我們這里配置了RoleVoter來進行投票：publicintvote(Authenticationauthentication,Objectobject,ConfigAttributeDefinitionconfig){intresult=ACCESS_ABSTAIN;〃這里取得資源的安全配置Iteratoriter=config.getConfigAttributes();40.while(iter.hasNext()){ConfigAttributeattribute=(ConfigAttribute)iter.next();43.if(this.supports(attribute)){result=ACCESS_DENIED;46.//這里對資源配置的安全授權級別進行判斷，也就是匹配ROLE為前綴的角色配置//遍歷每個配置屬性，如果其中一個匹配該主體持有的GrantedAuthority,則訪問被允許。for(inti=0;i<authentication.getAuthorities().1ength;i++){if(attribute.getAttribute().equals(authentication.getAuthorities()[i].getAuthority())){return