改善既有的代码-重构(ppt).ppt

重构技术,邱百超badqiu(a),讲解内容,重构介绍重构原则代码的坏味道重构技巧重构工具使用实例Qif(name!=nullif(age!=nullif(!isNullOrEmpty(name).Stringage=request.getParameter(Age);if(!isNullOrEmpty(age).privatebooleanisNullOrEmpty(finalStringstring)if(string!=null,ExtractMethods(提炼函数：清除注释）,voidprintOwing()/printbannerSystem.out.println(“*”);System.out.println(“Banner”);System.out.println(“*”);/printdetailsSystem.out.println(name:+_name);System.out.println(amount+getOutstanding();,voidprintOwing()printBanner();printDetails(getOutstanding();voidprintBanner()System.out.println(“*”);System.out.println(“Banner”);System.out.println(“*”);voidprintDetails(doubleoutstanding)System.out.println(name:+_name);System.out.println(amount+outstanding);,InlineMethod(将函数内联化),InlineTemp（将临时变量内联化）,ReplaceTempwithQuery（以查询取代临时变量）,doublebasePrice=_quantity*_itemPrice;if(basePrice1000)returnbasePrice*0.95;elsereturnbasePrice*0.98;,if(basePrice()1000)returnbasePrice()*0.95;elsereturnbasePrice()*0.98;.doublebasePrice()return_quantity*_itemPrice;,IntroduceExplainingVariable（引入解释性变量）,booleanisMacOs=platform.toUpperCase().indexOf(MAC)-1;booleanisIEBrowser=browser.toUpperCase().indexOf(IE)-1;booleanwasResized=resize0;if(isMacOsSystem.out.println(temp);temp=_height*_width;System.out.println(temp);,doubleperimeter=2*(_height+_width);System.out.println(perimeter);doublearea=_height*_width;System.out.println(area);,RemoveAssignmentstoParameters（移除对参数的赋值）,ReplaceMethodwithMethodObject（以函数对象取代函数）,SubstituteAlgorithm（替换算法）,ReplaceNestedConditionalwithGuardClauses,doublegetPayAmount()doubleresult;if(_isDead)result=deadAmount();elseif(_isSeparated)result=separatedAmount();elseif(_isRetired)result=retiredAmount();elseresult=normalPayAmount();returnresult;,doublegetPayAmount()if(_isDead)returndeadAmount();if(_isSeparated)returnseparatedAmount();if(_isRetired)returnretiredAmount();returnnormalPayAmount();,SplitLoop-1,voidprintValues()doubleaverageAge=0;doubletotalSalary=0;for(inti=0;ipeople.length;i+)averageAge+=peoplei.age;totalSalary+=peoplei.salary;averageAge=averageAge/people.length;System.out.println(averageAge);System.out.println(totalSalary);,voidprintValues()doubletotalSalary=0;for(inti=0;ipeople.length;i+)totalSalary+=peoplei.salary;doubleaverageAge=0;for(inti=0;ipeople.length;i+)averageAge+=peoplei.age;averageAge=averageAge/people.length;System.out.println(averageAge);System.out.println(totalSalary);,SplitLoop-2,voidprintValues()System.out.println(averageAge();System.out.println(totalSalary();privatedoubleaverageAge()doubleresult=0;for(inti=0;ipeople.length;i+)result+=peoplei.age;returnresult/people.length;privatedoubletotalSalary()doubleresult=0;for(inti=0;ipeople.length;i+)result+=peoplei.salary;returnresult;,简化条件表达式,分解表达式,if(date.before(SUMMER_START)|date.after(SUMMER_END)charge=quantity*_winterRate+_winterServiceCharge;elsecharge=quantity*_summerRate,if(notSummer(date)charge=winterCharge(quantity);elsecharge=summerCharge(quantity);,RemoveDoubleNegative,if(!item.isNotFound()if(item.isFound(),在对象之间搬移特性,搬移函数（MoveMethod)搬移值域(MoveField)提炼类(ExtractClass)将类内联化(InlineClass)隐藏委托关系(HideDelegat