How to convert the apex class into batch apex class? [closed]

Question

public class MonPipelineReport{    
    public static void Get_Officer()
    {
        Date startDate = Date.today().addMonths(-1);
        startDate = Date.newInstance(startDate.year(),startDate.month(),1);
        Date endDate = startDate;
        Integer days = Date.daysInMonth(endDate.year(), endDate.month());
        endDate = Date.newInstance(startDate.year(),startDate.month(),days);
        List<Lead> allLeads = [SELECT Loan_Officer_1a__c,Loan_Officer_1a__r.Email, Name, Phone, Starting_Credit_Score__c, 
                               Status, Enrolled_On__c, Est_Re_Pull_Date__c, Realtor_Name__c 
                               FROM Lead WHERE CreatedDate >=: startDate AND CreatedDate <=: endDate AND Loan_Officer_1a__c != null LIMIT 50000];
        EmailTemplate templateId = [Select Id,HtmlValue,Subject from EmailTemplate where name = 'LoanOfficerRecord' LIMIT 1];
        Map<Id,List<Lead>> leadMap = new Map<Id,List<Lead>>();
        List<Messaging.SingleEmailMessage> mails = new List<Messaging.SingleEmailMEssage>();
        if(allLeads != null && allLeads.size() > 0){
            for(Lead l: allLeads){
                if(!leadMap.containsKey(l.Loan_Officer_1a__c)){
                    leadMap.put(l.Loan_Officer_1a__c, new List<lead>());
                }
                leadMap.get(l.Loan_Officer_1a__c).add(l);
            }
        }
        if(leadMap.keySet().size() > 0){
            Map<Id,Contact> officers = new Map<Id,Contact>([SELECT Id,Email,Name FROM Contact WHERE Id IN: leadMap.keySet()]);
            for(Id i: leadMap.keySet()){
                Contact con = officers.get(i);
                System.debug(con);
                if(String.isnOtBlank(con.Email)){
                    Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
                    mail.setToAddresses(new String[]{con.EMail});
                    mail.setSubject(templateId.Subject);
                    String html = templateId.HtmlValue;
                    html = html.replace('||OfficerName||',con.Name);
                    String leadsTable = '<table cellpadding="3" cellspacing="3" width="100%" align="center" border="1" style="border-collapse:collapse;">'+
                        '<tr style="font-weight:bold;"><td>Name</td><td>Phone</td><td>Starting Credit Score</td><td>Status</td><td>Enrolled On</td><td>Est. Re Pull Date</td><td>Realtor Name</td></tr>';
                    for(Lead l: leadMap.get(i)){
                        leadsTable += '<tr><td>'+l.Name+'</td>'+
                            '<td>'+l.Phone+'</td><td>'+l.Starting_Credit_Score__c+'</td><td>'+l.Status+'</td><td>'+l.Enrolled_On__c+'</td>'+
                            '<td>'+l.Est_Re_Pull_Date__c+'</td><td>'+l.Realtor_Name__c+'</td></tr>';
                    }
                    leadsTable += '</table>';
                    html = html.replace('||Leads||',leadsTable);
                    mail.setHTMLBody(html);
                    mails.add(mail);
                }
            }
        }
        if(mails.size() > 0){
            Messaging.sendEmail(mails);
        }
    }

Answer 1

try the code below.

global class MonPipelineReportBatch implements Database.Batchable<sObject> {
    public String query = 'SELECT Loan_Officer_1a__c,Loan_Officer_1a__r.Email, Name, Phone, Starting_Credit_Score__c, ' 
                          +  'Status, Enrolled_On__c, Est_Re_Pull_Date__c, Realtor_Name__c ' 
                          +   ' FROM Lead';
    public EmailTemplate templateId = [Select Id,HtmlValue,Subject from EmailTemplate where name = 'LoanOfficerRecord' LIMIT 1];

    global Database.QueryLocator start(Database.BatchableContext bc) {
        Date startDate = Date.today().addMonths(-1);
    startDate = Date.newInstance(startDate.year(),startDate.month(),1);
    Datetime realStartDate = Datetime.newInstance(startDate, Time.newInstance(0, 0, 0, 0));

    Date endDate = startDate;
    Integer days = Date.daysInMonth(endDate.year(), endDate.month());
    endDate = Date.newInstance(startDate.year(),startDate.month(),days);
    Datetime realEndDate = Datetime.newInstance(endDate.addDays(1), Time.newInstance(0, 0, 0, 0));

    query += ' WHERE CreatedDate >= ' + realStartDate + ' AND CreatedDate <= ' + realEndDate + ' AND Loan_Officer_1a__c != null';
    return Database.getQueryLocator(query);
    }

    global void execute(Database.BatchableContext BC, list<Lead> allLeads) {
        Map<Id,List<Lead>> leadMap = new Map<Id,List<Lead>>();
        List<Messaging.SingleEmailMessage> mails = new List<Messaging.SingleEmailMEssage>();
        if(allLeads != null && allLeads.size() > 0){
            for(Lead l: allLeads){
                if(!leadMap.containsKey(l.Loan_Officer_1a__c)){
                    leadMap.put(l.Loan_Officer_1a__c, new List<lead>());
                }
                leadMap.get(l.Loan_Officer_1a__c).add(l);
            }
        }
        if(leadMap.keySet().size() > 0){
            Map<Id,Contact> officers = new Map<Id,Contact>([SELECT Id,Email,Name FROM Contact WHERE Id IN: leadMap.keySet()]);
            for(Id i: leadMap.keySet()){
                Contact con = officers.get(i);
                System.debug(con);
                if(String.isnOtBlank(con.Email)){
                    Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
                    mail.setToAddresses(new String[]{con.EMail});
                    mail.setSubject(templateId.Subject);
                    String html = templateId.HtmlValue;
                    html = html.replace('||OfficerName||',con.Name);
                    String leadsTable = '<table cellpadding="3" cellspacing="3" width="100%" align="center" border="1" style="border-collapse:collapse;">'+
                        '<tr style="font-weight:bold;"><td>Name</td><td>Phone</td><td>Starting Credit Score</td><td>Status</td><td>Enrolled On</td><td>Est. Re Pull Date</td><td>Realtor Name</td></tr>';
                    for(Lead l: leadMap.get(i)){
                        leadsTable += '<tr><td>'+l.Name+'</td>'+
                            '<td>'+l.Phone+'</td><td>'+l.Starting_Credit_Score__c+'</td><td>'+l.Status+'</td><td>'+l.Enrolled_On__c+'</td>'+
                            '<td>'+l.Est_Re_Pull_Date__c+'</td><td>'+l.Realtor_Name__c+'</td></tr>';
                    }
                    leadsTable += '</table>';
                    html = html.replace('||Leads||',leadsTable);
                    mail.setHTMLBody(html);
                    mails.add(mail);
                }
            }
        }
        if(mails.size() > 0){
            Messaging.sendEmail(mails);
        }
    }

    global void finish(Database.BatchableContext BC) {

    }
   }