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Apex - 接口
由 kaikai0220 创建,youj 最后一次修改 2016-12-12 什么是接口? 接口就像一个Apex类,其中没有一个方法被实现。 它只包含方法签名,但每个方法的主体是空的。 要使用接口,另一个类必须通过为接口中包含的所有方法提供一个体来实现它。 接口主要用于为代码提供抽象层。 它们将实现与方法的声明分开。 让我们举一个化学公司的例子。 假设我们需要向高级和普通客户提供折扣,两者的折扣将不同。 我们将创建一个接口,称为discountprocessor。 //Interfacepublic interface DiscountProcessor{Double percentageDiscountTobeApplied();//method signature only}//Premium Customer Classpublic class PremiumCustomer implements DiscountProcessor{//Method Callpublic Double percentageDiscountTobeApplied () {//For Premium customer, discount should be 30%return 0.30;}}//Normal Customer Classpublic class NormalCustomer implements DiscountProcessor{//Method Callpublic Double percentageDiscountTobeApplied () {//For Premium customer, discount should be 10%return 0.10;}}当你实现接口,那么强制实现该接口的方法。 如果你不实现Interface方法,它会抛出一个错误。 当您想要让开发人员强制实施方法时,您应该使用Interfaces。 批处理的标准Salesforce接口 SFDC有标准接口,如Database.Batchable,Schedulable等。例如,如果实现Database.Batchable接口,那么必须实现接口中定义的三个方法:开始,执行和完成。 以下是标准Salesforce提供的Database.Batchable接口的示例,该接口向具有批处理状态的用户发送电子邮件。 此界面有3种方法,“开始”,“执行”和“完成”。 使用这个接口,我们可以实现Batchable功能,它提供了BatchableContext变量,我们可以使用它来获取有关正在执行的Batch的更多信息,并执行其他功能。 global class CustomerProessingBatch implements Database.Batchable<sobject>, Schedulable{//Add here your email addressglobal String [] email = new String[] {'test@test.com'}; //Start Methodglobal Database.Querylocator start (Database.BatchableContext BC) { //This is the Query which will determine the scope of Records and fetching the same return Database.getQueryLocator('Select id, Name, APEX_Customer_Status__c, APEX_Customer_Decscription__c From APEX_Customer__c WHERE createdDate = today && APEX_Active__c = true');}//Execute methodglobal void execute (Database.BatchableContext BC, List<sobject> scope) { List<apex_customer__c> customerList = new List<apex_customer__c>(); List<apex_customer__c> updtaedCustomerList = new List<apex_customer__c>(); for (sObject objScope: scope) { //type casting from generic sOject to APEX_Customer__c APEX_Customer__c newObjScope = (APEX_Customer__c)objScope ; newObjScope.APEX_Customer_Decscription__c = 'Updated Via Batch Job'; newObjScope.APEX_Customer_Status__c = 'Processed'; //Add records to the List updtaedCustomerList.add(newObjScope); } //Check if List is empty or not if (updtaedCustomerList != null && updtaedCustomerList.size()>0) {//Update the Records Database.update(updtaedCustomerList); System.debug('List Size '+updtaedCustomerList.size()); }}//Finish Methodglobal void finish(Database.BatchableContext BC){ Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); //get the job Id AsyncApexJob a = [Select a.TotalJobItems, a.Status, a.NumberOfErrors, a.JobType, a.JobItemsProcessed, a.ExtendedStatus, a.CreatedById, a.CompletedDate From AsyncApexJob a WHERE id = :BC.getJobId()]; System.debug('$$$ Jobid is'+BC.getJobId()); //below code will send an email to User about the status mail.setToAddresses(email); //Add here your email address mail.setReplyTo('test@test.com'); mail.setSenderDisplayName('Apex Batch Processing Module'); mail.setSubject('Batch Processing '+a.Status); mail.setPlainTextBody('The Batch Apex job processed '+a.TotalJobItems+'batches with '+a.NumberOfErrors+'failures'+'Job Item processed are'+a.JobItemsProcessed); Messaging.sendEmail(new Messaging.Singleemailmessage [] {mail});}//Scheduler Method to scedule the classglobal void execute(SchedulableContext sc){ CustomerProessingBatch conInstance = new CustomerProessingBatch(); database.executebatch(conInstance,100);}}要执行这个类,你必须在开发者控制台中运行下面的代码。CustomerProessingBatch objBatch = new CustomerProessingBatch ();Database.executeBatch(objBatch);
Apex - 接口