第8章 实现关联关系.ppt

课程回顾Boat类 抽象类和最终类 重写超类方法 受保护访问Lease类 抽象方法 Java接口 第8章实现关联关系 将Customer与Boat相关联 一对一的关联关系向Boat类中添加功能将Dock与Slip相关联 一对多的关联关系创建和使用关联类 Lease 第8章实现关联关系 CustomernameaddressphoneNo DockdockIDlocationelectricitywateraddSliptoDock LeaseamountstartDateendDatecalculateFee SlipslipIDwidthslipLength BoatstateRegistrationNoboatLengthmanufacturerYear 1 0 1 0 1 0 1 1 1 0 1 0 1 类图 CoveredSlipheightdoor 8 1查看Marina的类图 Bradshaw类图显示以下关联关系 客户拥有船只 船只被客户拥有 船只被指定给船台 船台包含船只 码头包含许多船台 船台被连接到码头 船台被租给客户 Lease是一个关联类 客户租用船台 8 1查看Marina的类图 船只必须被客户拥有 Boat和Customer之间是强制关系 客户不一定拥有船只 Customer和Boat之间是可选关系 使用Java实现关联关系的方法 在Boat类中添加属性 Customer类的引用变量 在Customer类中添加属性 Boat类的引用变量 8 2将Customer与Boat相关联 一对一的关联关系 修改Customer类 publicclassCustomer attributedefinitionsprivateStringname privateStringaddress privateStringphoneNo referencevariableforBoatinstanceprivateBoatboat 8 2将Customer与Boat相关联 一对一的关联关系 constructorwithparameterspublicCustomer StringaName StringanAddress StringaPhoneNo invokeaccessorstopopulateattributessetName aName setAddress anAddress setPhoneNo aPhoneNo initiallynoBoatsetBoat null 8 2将Customer与Boat相关联 一对一的关联关系 getaccessorspublicStringgetName returnname publicStringgetAddress returnaddress publicStringgetPhoneNo returnphoneNo publicBoatgetBoat returnboat 8 2将Customer与Boat相关联 一对一的关联关系 setaccessorspublicvoidsetName StringnewName name newName publicvoidsetAddress StringnewAddress address newAddress publicvoidsetPhoneNo StringnewPhoneNo phoneNo newPhoneNo publicvoidsetBoat BoataBoat boat aBoat 8 2将Customer与Boat相关联 一对一的关联关系 publicclassTesterOneA publicstaticvoidmain Stringargs createaCustomerinstanceCustomerfirstCustomer newCustomer Eleanor Atlanta 123 4567 createaBoatinstanceBoatfirstBoat newBoat MO34561 28 Tartan 2002 settheBoatforthecustomerfirstCustomer setBoat firstBoat BoataBoat firstCustomer getBoat System out println Customerboatinformationis aBoat getStateRegistrationNo aBoat getManufacturer aBoat getLength aBoat getYear 8 2将Customer与Boat相关联 一对一的关联关系 System out println Again customerboatinformationis firstCustomer getBoat getStateRegistrationNo firstCustomer getBoat getManufacturer firstCustomer getBoat getLength firstCustomer getBoat getYear 8 2将Customer与Boat相关联 一对一的关联关系 CustomerboatinformationisMO34561Tartan28 02002Again customerboatinformationisMO34561Tartan28 02002Pressanykeytocontinue 8 2将Customer与Boat相关联 一对一的关联关系 修改Boat类实现另一个方向上的关系 船只被客户拥有 publicclassBoat attributesprivateStringstateRegistrationNo privatedoublelength privateStringmanufacturer privateintyear referencevariablepointstoaCustomerinstanceprivateCustomercustomer 8 2将Customer与Boat相关联 一对一的关联关系 constructorpublicBoat StringaStateRegistrationNo doubleaLength StringaManufacturer intaYear setStateRegistrationNo aStateRegistrationNo setLength aLength setManufacturer aManufacturer setYear aYear initiallynoCustomerforthisboatsetCustomer null 8 2将Customer与Boat相关联 一对一的关联关系 建立两个方向上的关系publicvoidassignBoatToCustomer CustomeraCustomer setCustomer aCustomer pointBoattotheCustomer instancecustomer setBoat this pointCustomertothisBoat 8 2将Customer与Boat相关联 一对一的关联关系 setaccessormethodspublicvoidsetStateRegistrationNo StringaStateRegistrationNo stateRegistrationNo aStateRegistrationNo publicvoidsetLength doubleaLength length aLength publicvoidsetManufacturer StringaManufacturer manufacturer aManufacturer publicvoidsetYear intaYear year aYear publicvoidsetCustomer CustomeraCustomer customer aCustomer 8 2将Customer与Boat相关联 一对一的关联关系 getaccessormethodspublicStringgetStateRegistrationNo returnstateRegistrationNo publicdoublegetLength returnlength publicStringgetManufacturer returnmanufacturer publicintgetYear returnyear publicCustomergetCustomer returncustomer 8 2将Customer与Boat相关联 一对一的关联关系 publicclassTesterOneB publicstaticvoidmain Stringargs createaCustomerinstanceCustomerfirstCustomer newCustomer Eleanor Atlanta 123 4567 createaBoatinstanceBoatfirstBoat newBoat MO34561 28 Tartan 2002 assigntheBoattotheCustomerfirstBoat assignBoatToCustomer firstCustomer 8 2将Customer与Boat相关联 一对一的关联关系 verifyBoattoCustomerassociation askboatforitsCustomerreference thenuseitwithCustomeraccessorSystem out println Boatownerinformationis firstBoat getCustomer getName firstBoat getCustomer getAddress firstBoat getCustomer getPhoneNo verifyCustomertoBoatassociation askCustomerforitsBoatreference thenuseitwithBoataccessorSystem out println Customerboatinformationis firstCustomer getBoat getStateRegistrationNo firstCustomer getBoat getManufacturer firstCustomer getBoat getLength firstCustomer getBoat getYear 8 2将Customer与Boat相关联 一对一的关联关系 BoatownerinformationisEleanorAtlanta123 4567CustomerboatinformationisMO34561Tartan28 02002Pressanykeytocontinue 8 2将Customer与Boat相关联 一对一的关联关系 将Boat和Customer之间的关系变为强制的 而不是可选的 在Boat的构造函数中增加参数 Customer引用Boat构造函数的头为 constructorpublicBoat StringaStateRegistrationNo doubleaLength StringaManufacturer intaYear CustomeraCustomer 构造函数中的代码为所有的属性设置值 然后调用assignBoatToCustomer方法 该方法会设置Boat的Customer属性并请求Costomer设置其boat属性 8 3向Boat类中添加功能 constructorpublicBoat StringaStateRegistrationNo doubleaLength StringaManufacturer intaYear CustomeraCustomer setStateRegistrationNo aStateRegistrationNo setLength aLength setManufacturer aManufacturer setYear aYear initiallynoCustomerforthisboat setCustomer null assignBoatToCustomer aCustomer 8 3向Boat类中添加功能 增加tellAboutSelf方法 由于Boat和Customer之间的关联是强制的 tellAboutSelf方法可以返回与船只有关的信息 及与拥有该船只的客户有关的信息 publicStringtellAboutSelf StringboatDetails IamBoat stateregnumber getStateRegistrationNo length getLength Manufacturer getManufacturer Year getYear StringcustomerDetails nandOwneris customer getName livingin customer getAddress withphone customer getPhoneNo returnboatDetails customerDetails 8 3向Boat类中添加功能 publicclassTesterTwo publicstaticvoidmain Stringargs createseveralcustomersCustomerfirstCustomer newCustomer Eleanor Atlanta 123 4567 CustomersecondCustomer newCustomer JoAnn StLouis 987 6543 createboatspassingcustomerreferencesBoatfirstBoat newBoat MO34561 28 Tartan 2002 firstCustomer BoatsecondBoat newBoat MO98765 32 Catalina 2001 secondCustomer useBoattellAboutSelfmethodtogetbackdetailsSystem out println firstBoat tellAboutSelf System out println secondBoat tellAboutSelf 8 3向Boat类中添加功能 IamBoatstateregnumberMO34561length28 0ManufacturerTartanYear2002andOwnerisEleanorlivinginAtlantawithphone123 4567IamBoatstateregnumberMO98765length32 0ManufacturerCatalinaYear2001andOwnerisJoAnnlivinginStLouiswithphone987 6543Pressanykeytocontinue 8 3向Boat类中添加功能 Slip与Dock在两个方向上都有关联关系 船台被连接到码头 码头包含许多船台 实现一对多的关联关系要求Dock实例有一个以上船台的引用变量 可以在Dock类中使用Vector保存多个Slip类的引用变量 8 4将Dock与Slip相关联 一对多的关联关系 Dock类定义属性 ID号位置 location 有电 electricity 有水 water slips 8 4将Dock与Slip相关联 一对多的关联关系 importjava util publicclassDock attributesprivateintid privateStringlocation privatebooleanelectricity privatebooleanwater implementslipassociationwithVectorclassprivateVectorslips 8 4将Dock与Slip相关联 一对多的关联关系 constructorpublicDock intanId StringaLocation booleananElectricity booleanaWater setId anId setLocation aLocation setElectricity anElectricity setWater aWater slips newVector 10 startwithVectorfor10slips custommethodaddSlipToDockpublicvoidaddSlipToDock SlipaSlip slips addElement aSlip connectdocktoslip 1 aSlip setDock this connectsliptodock 1 1 8 4将Dock与Slip相关联 一对多的关联关系 setaccessormethodspublicvoidsetId intanId id anId publicvoidsetLocation StringaLocation location aLocation publicvoidsetElectricity booleananElectricity electricity anElectricity publicvoidsetWater booleanaWater water aWater 8 4将Dock与Slip相关联 一对多的关联关系 custommethodtoreturnvectorofslipspublicVectorgetSlips returnslips getaccessormethodspublicintgetId returnid publicStringgetLocation returnlocation publicbooleangetElectricity returnelectricity publicbooleangetWater returnwater 8 4将Dock与Slip相关联 一对多的关联关系 将Slip类与Dock相关联修改Slip类定义 增加Dock引用变量作为属性 修改构造函数 增加Dock引用参数 这样 实例化Slip时 就必须与Dock相关联 构造函数中的语句还会请求码头向码头添加船台 以便在两个方向建立关联关系 8 4将Dock与Slip相关联 一对多的关联关系 SlipwithBoatreferenceandaccessors andDockreferencevariableandaccessorspublicclassSlip attributesprivateintno privateintwidth privatedoubleslipLength privateBoatboat privateDockdock 8 4将Dock与Slip相关联 一对多的关联关系 constructorwith3parametersplusdockreferencepublicSlip intaNo intaWidth doubleaSlipLength DockaDock invokeaccessorstopopulateattributessetNo aNo setWidth aWidth setSlipLength aSlipLength assignsliptoanexistingdocksetDock aDock telldocktoassociatewiththisslipdock addSlipToDock this initiallynoboatinslipsetBoat null 8 4将Dock与Slip相关联 一对多的关联关系 setaccessormethodspublicvoidsetNo intaNo no aNo publicvoidsetWidth intaWidth width aWidth publicvoidsetSlipLength doubleaSlipLength slipLength aSlipLength publicvoidsetBoat BoataBoat boat aBoat publicvoidsetDock DockaDock dock aDock 8 4将Dock与Slip相关联 一对多的关联关系 getaccessormethodspublicintgetNo returnno publicintgetWidth returnwidth publicdoublegetSlipLength returnslipLength publicBoatgetBoat returnboat publicDockgetDock returndock 8 4将Dock与Slip相关联 一对多的关联关系 测试 码头包含船台 关联关系声明一个Dock及3个Slip引用变量 并进行实例化 将3个Slip能够与该Dock关联 且该Dock能够与每个Slip关联 8 4将Dock与Slip相关联 一对多的关联关系 DockhasSlips ignoresBoatandCustomerfornow importjava util publicclassTesterThreeA publicstaticvoidmain Stringargs declareDockandSlipreferencevariablesDockfirstDock SlipfirstSlip SlipsecondSlip SlipthirdSlip 8 4将Dock与Slip相关联 一对多的关联关系 createaDockinstancefirstDock newDock 1 MainCove true false createthreeSlipinstancesfortheDockfirstSlip newSlip 1 10 20 firstDock secondSlip newSlip 2 12 25 firstDock thirdSlip newSlip 3 14 25 firstDock 8 4将Dock与Slip相关联 一对多的关联关系 verifyDocktoSlipassociation 1tomany firstgettheVectorofslipsfromtheDockVectorslips firstDock getSlips nextuseVectorsizemethodtogetnumberofslipsSystem out println Dock1has slips size slips iteratethroughVectortogetinformationoneachslipfor inti 0 i slips size i getslipreferencevariablefromslipsVectorofDockSlipaSlip Slip slips elementAt i verifyslipinformationSystem out println Slipnumber aSlip getNo haswidthof aSlip getWidth haslengthof aSlip getSlipLength 8 4将Dock与Slip相关联 一对多的关联关系 verifysliptodockassociation 1 1 System out println FirstslipisonDock firstSlip getDock getId withlocation firstSlip getDock getLocation withelectricity firstSlip getDock getElectricity andwater firstSlip getDock getWater 8 4将Dock与Slip相关联 一对多的关联关系 Dock1has3slipsSlipnumber1haswidthof10haslengthof20 0Slipnumber2haswidthof12haslengthof25 0Slipnumber3haswidthof14haslengthof25 0FirstslipisonDock1withlocationMainCovewithelectricitytrueandwaterfalsePressanykeytocontinue 8 4将Dock与Slip相关联 一对多的关联关系 向示例中添加Boat和Customer类对Boat类进行修改 增加Slip引用属性和存取器方法 以便与Slip关联 最初不必将Boat指定给Slip 这样构造函数就可以将Slip引用属性设置为null了 增加assignBoatToSlip方法 8 4将Dock与Slip相关联 一对多的关联关系 publicclassBoat attributesprivateStringstateRegistrationNo privatedoublelength privateStringmanufacturer privateintyear referencevariablepointstoaCustomerinstanceprivateCustomercustomer 增加对Slip的引用privateSlipslip 8 4将Dock与Slip相关联 一对多的关联关系 constructor addingCustomerreference publicBoat StringaStateRegistrationNo doubleaLength StringaManufacturer intaYear CustomeraCustomer setStateRegistrationNo aStateRegistrationNo setLength aLength setManufacturer aManufacturer setYear aYear 建立boat和customer的关联assignBoatToCustomer aCustomer setSlip null boatnotinslipyet 8 4将Dock与Slip相关联 一对多的关联关系 将Boat指定给CustomerpublicvoidassignBoatToCustomer CustomeraCustomer setCustomer aCustomer customer setBoat this 将Boat指定到SlippublicvoidassignBoatToSlip SlipaSlip setSlip aSlip slip setBoat this 8 4将Dock与Slip相关联 一对多的关联关系 tellAboutSelfmethodreturningBoatandCustomerinformationpublicStringtellAboutSelf StringboatDetails IamaBoat stateregnumber getStateRegistrationNo length getLength Manufacturer getManufacturer Year getYear StringcustomerDetails nandOwneris customer getName livingin customer getAddress withphone customer getPhoneNo returnboatDetails customerDetails 8 4将Dock与Slip相关联 一对多的关联关系 setaccessormethodspublicvoidsetStateRegistrationNo StringaStateRegistrationNo stateRegistrationNo aStateRegistrationNo publicvoidsetLength doubleaLength length aLength publicvoidsetManufacturer StringaManufacturer manufacturer aManufacturer publicvoidsetYear intaYear year aYear publicvoidsetCustomer CustomeraCustomer customer aCustomer publicvoidsetSlip SlipaSlip slip aSlip 8 4将Dock与Slip相关联 一对多的关联关系 getaccessormethodspublicStringgetStateRegistrationNo returnstateRegistrationNo publicdoublegetLength returnlength publicStringgetManufacturer returnmanufacturer publicintgetYear returnyear publicCustomergetCustomer returncustomer publicSlipgetSlip returnslip 8 4将Dock与Slip相关联 一对多的关联关系 根据目前的关联关系 如果有Customer引用 即可导航以查找客户的船只 它所在的船台及其所在的码头 同样 如果有Dock引用 即可查找每个船台并导航到船台的船只和拥有船只的客户 TestThreeB提供对这些关联关系的综合测试 8 4将Dock与Slip相关联 一对多的关联关系 TesterThreeB DockhasSlipswithBoatandCustomerimportjava util publicclassTesterThreeB publicstaticvoidmain Stringargs declarereferencevariablesDockfirstDock SlipfirstSlip SlipsecondSlip CustomerfirstCustomer CustomersecondCustomer BoatfirstBoat BoatsecondBoat 8 4将Dock与Slip相关联 一对多的关联关系 createaDockinstancefirstDock newDock 1 MainCove true false createtwoSlipinstancesfortheDockfirstSlip newSlip 1 10 20 firstDock secondSlip newSlip 2 12 25 firstDock createtwoCustomerinstancesfirstCustomer newCustomer Eleanor Atlanta 123 4567 secondCustomer newCustomer JoAnn StLouis 987 6543 8 4将Dock与Slip相关联 一对多的关联关系 createBoatspassingCustomerreferencesfirstBoat newBoat MO34561 28 Tartan 2002 firstCustomer secondBoat newBoat MO98765 32 Catalina 2001 secondCustomer assigntheBoatstotheSlipsfirstBoat assignBoatToSlip firstSlip secondBoat assignBoatToSlip secondSlip verifyCustomertoBoattoSliptoDockSystem out println Informationforcustomer firstCustomer getName nBoatis firstCustomer getBoat getManufacturer nSlipis firstCustomer getBoat getSlip getNo nDockis firstCustomer getBoat getSlip getDock getId 8 4将Dock与Slip相关联 一对多的关联关系 verifyDocktoSliptoBoatassociation 1tomany firstgettheVectorofslipsfromtheDockVectorslips firstDock getSlips nextuseVectorsizemethodtogetnumberofslipsSystem out println Dock1has slips size slips iteratethroughVectortogetinformationoneachSlipfor inti 0 i slips size i SlipaSlip Slip slips elementAt i verifySliptoBoattoCustomerSystem out println Slipnumber aSlip getNo haswidthof aSlip getWidth haslengthof aSlip getSlipLength ncontaining aSlip getBoat tellAboutSelf 8 4将Dock与Slip相关联 一对多的关联关系 InformationforcustomerEleanorBoatisTartanSlipis1Dockis1Dock1has2slipsSlipnumber1haswidthof10haslengthof20 0containingIamaBoatstateregnumberMO34561length28 0ManufacturerTartanYear2002andOwnerisEleanorlivinginAtlantawithphone123 4567Slipnumber2haswidthof12haslengthof25 0containingIamaBoatstateregnumberMO98765length32 0ManufacturerCatalinaYear2001andOwnerisJoAnnlivinginStLouiswithphone987 6543Pressanykeytocontinue 8 4将Dock与Slip相关联 一对多的关联关系 Lease类层次结构是一个关联类 表示租约是客户和船台之间的关联关系 具有起始日期 终止日期 租金等属性 Customer和Slip之间是一对一的关联关系 将Lease连接到此关系的虚线表示每个客户和船台之间有一份租约 8 5创建和使用关联类 Lease CustomernameaddressphoneNo LeaseamountstartDateendDatecalculateFee SlipslipIDwidthslipLength 1 1 类图 AnnualLeasepayMonthlybalanceDuecalculateFee DailyLeasenumberOfDayscalculateFee 8 5创建和使用关联类 Lease 对Lease超类进行修改 使其包括Slip引用属性 及Customer引用属性 增加相应的存取器方法 8 5创建和使用关联类 Lease 修改后的Lease类定义 AbstactinitialLeaseclasstoextendwithabstractmethod plusSlipandCustomerreferenceattributesandaccessorsimportjava util forDateandCalendarclassespublicabstractclassLease attributesprivatedoubleamount privateDatestartDate privateDateendDate 建立对组成该Lease的Coustomer和Slip的引用Customercustomer Slipslip 8 5创建和使用关联类 Lease constructorpublicLease DateaStartDate setStartDate aStartDate setEndDate null setAmount 0 nocustomerorslipyetsetCustomer null setSlip null 8 5创建和使用关联类 Lease abstractmethodsubclassesmustoverridepublicabstractdoublecalculateFee intaLength setaccessormethodspublicvoidsetAmount doubleanAmount amount anAmount publicvoidsetStartDate DateaStartDate startDate aStartDate publicvoidsetEndDate DateanEndDate endDate anEndDate publicvoidsetCustomer CustomeraCustomer customer aCustomer publicvoidsetSlip SlipaSlip slip aSlip 8 5创建和使用关联类 Lease getaccessormethodspublicdoublegetAmount returnamount publicDategetStartDate returnstartDate publicDategetEndDate returnendDate publicCustomergetCustomer returncustomer publicSlipgetSlip returnslip 8 5创建和使用关联类 Lease Boat不与Lease直接关联 所以类定义不必修改 Customer类确实与Lease有关联关系 所以必须添加Lease引用属性以及存取器方法 对Slip类进行修改 添加Lease引用属性以及存取器方法 添加用于创建Lease实例并将它与Customer以及Slip相关联的自定义方法 由于AnnualLease和DailyLease具有包含不同参数的构造函数 这里只包含创建年租约的方法LeaseAnnualSlip 8 5创建和使用关联类 Lease 修改后的Slip类定义 importjava util publicclassSlip attributesprivateintno privateintwidth privatedoubleslipLength privateBoatboat privateLeaselease 8 5创建和使用关联类 Lease constructorwith3parameterspublicSlip intaNo intaWidth doubleaSlipLength invokeaccessorstopopulateattributessetNo aNo setWidth aWidth setSlipLength aSlipLength setBoat null initiallynoboatisassignedtothisslipsetLease null initiallynoleaseforthisslip 8 5创建和使用关联类 Lease custommethodleaseSlipcreatesAnnualLeaseinstance note sliptakesresponsibilityformuchprocessingpublicvoidleaseAnnualSlip CustomeraCustomer DateaStartDate booleanisPayMonthly createAnnualLeaseinstanceandassignittolease whichisanattributeofthissliplease newAnnualLease aStartDate width isPayMonthly tellleasetosetit ssliptothissliplease setSlip this tellleasetosetitscustomerlease setCustomer aCustomer tellcustomertosetitsleaseaCustomer setLease lease 8 5创建和使用关联类 Lease setaccessormethodspublicvoidsetNo intaNo no aNo publicvoidsetWidth intaWidth width aWidth publicvoidsetSlipLength doubleaSlipLength slipLength aSlipLength publicvoidsetBoat BoataBoat boat aBoat publicvoidsetLease LeaseaLease lease aLease 8 5创建和使用关联类 Lease getaccessormethodspublicintgetNo returnno publicintgetWidth returnwidth publicdoublegetSlipLength returnslipLength publicBoatgetBoat returnboat publicLeasegetLease returnlease 8 5创建和使用关联类 Lease TesterFour 创建一个Date用作起始日期 然后为客户 船只 船台和租约声明引用变量firstCustomer firstBoat firstSlip firstLease 对Customer Boat Slip实例化并将船只指定给船台 firstBoat assignBoatToSlip firstSlip 3 出租船台 firstSlip leaseAnnualSlip firstCustomer date1 true 8 5创建和使用关联类 Lease TesterFourtotestleaseAnnualSlipmethodofSlip thatcreatesAnnualLeaseandassociateseverythingimportjava util publicclassTesterFour publicstaticvoidmain Stringa