如下，在batch所有方法里边都有【Database.BatchableContext】Object，前边讲的的例子中，都没有用到BC，因为它是用来取得【AsyncApexJob】情报跟踪Job进程的，然后可以及时发送邮件共享信息还可以做成后台log并出力等等。
可以使用getJobId()方法取得AsyncApexJob信息。
代码语言：javascript复制global Database.QueryLocator start(Database.BatchableContext BC) {
return Database.getQueryLocator(query);
}
global void execute(Database.BatchableContext BC, list<sObject> scope) {
}
global void finish(Database.BatchableContext BC) {
}AsyncApexJob
项目名 详细
ApexClassId 执行Job的ApexClass的Id，参照先是ApexClass
CompletedDate Job完成日时
CronTriggerId 适用于ScheduledApex，取得关联的定时任务情报，参照先是CronTrigge
ExtendedStatus 处理中发生一个以上的错误时，最初的简单错误可以在这里查看
JobItemsProcessed Job项目数
JobType Job种类，有效值Future，SharingRecalculation，ScheduledApex，
BatchApex，BatchApexWorker，TestRequest，TestWorker，ApexToken，Queueable
NumberOfErrors 失败合计数
Status 状况，有效值Holding，Queued，Preparing，Processing，Aborted，Completed，Failed
TotalJobItems Batch合计数
实装例如下
代码语言：javascript复制global with sharing class ExampleBatchableContextBatch implements Database.Batchable<sObject>{
public final String query;
public final Id toUserId;
public final Id fromUserId;
global Database.QueryLocator start(Database.BatchableContext BC) {
return Database.getQueryLocator(query);
}
global void execute(Database.BatchableContext BC, list<sObject> scope) {
Savepoint sp = Database.setSavepoint();
try {
List<Opportunity> opps = new List<Opportunity>();
for(sObject item : scope){
Opportunity opp = (Opportunity)item;
if(opp.OwnerId == fromUserId){
opp.OwnerId=toUserId;
opps.add(opp);
}
}
update opps;
} catch (Exception ex) {
Database.rollback(sp);
}
}
global void finish(Database.BatchableContext BC) {
// Get the ID of the AsyncApexJob representing this batch job
// from Database.BatchableContext.
// Query the AsyncApexJob object to retrieve the current job's information.
system.debug('>>>>>>>>>>>>BC.getJobId()::' BC.getJobId());
AsyncApexJob jobItem = [SELECT Id, ApexClassId, ApexClass.Name, CompletedDate,
ExtendedStatus, JobType, MethodName, ParentJobId,Status, NumberOfErrors,
JobItemsProcessed,TotalJobItems, CreatedBy.Email
FROM AsyncApexJob
WHERE Id = :BC.getJobId()];
system.debug('>>>>>>>>>>>>AsyncApexJob::' jobItem);
// Send an email to the Apex job's submitter notifying of job completion.
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
String[] toAddresses = new String[] {jobItem.CreatedBy.Email};
mail.setToAddresses(toAddresses);
mail.setSubject('Apex Sharing Recalculation ' jobItem.Status);
mail.setPlainTextBody
('The batch Apex job processed ' jobItem.TotalJobItems ' batches with ' jobItem.NumberOfErrors ' failures.');
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
}Batch执行前Opportunity：
Batch执行：
代码语言：javascript复制Id fromUser = [SELECT Id, Name FROM User WHERE Name = 'System'].Id;
Id toUser = [SELECT Id, Name FROM User WHERE Name = 'logon xiang'].Id;
ExampleBatchableContextBatch reassign = new ExampleBatchableContextBatch();
reassign.query = 'SELECT Id, Name, OwnerId, Owner.Name FROM Opportunity WHERE DeleteFlg__c = true';
reassign.fromUserId = fromUser;
reassign.toUserId = toUser;
ID batchprocessid = Database.executeBatch(reassign);Batch执行后Opportunity:
AsyncApexJob信息：
AsyncApexJob::AsyncApexJob:{Id=7076g00005cbN89AAE, ApexClassId=01p6g00000SC1W3AAL, CompletedDate=2021-11-23 02:56:24, JobType=BatchApex, Status=Completed, NumberOfErrors=0, JobItemsProcessed=1, TotalJobItems=1, CreatedById=0056g000001OqErAAK}
邮件详细：
