ApexでREST API使用して画像ファイルUpload

    public void fileUpload(Attachment attach){


        HttpRequest req = new HttpRequest();
        Http http = new Http();
        HTTPResponse res = new HTTPResponse();

        String boundary = '------------' + String.valueOf(DateTime.now().getTime());

        String header += '--' + boundary;
        header += '\r\n';
        header += 'Content-Disposition: form-data; name="attach"; filename="' + attach.name + '"';
        header += '\r\n';
        header += 'Content-Type: ' + attach.ContentType;
        String headerEncoded = EncodingUtil.base64Encode(Blob.valueOf(header+'\r\n\r\n'));
        while(headerEncoded.endsWith('=')){
            header += ' ';
            headerEncoded = EncodingUtil.base64Encode(Blob.valueOf(header + ' ' +'\r\n\r\n'));
        }

        String bodyEncoded = EncodingUtil.base64Encode(attach.Body);

        String footor += '\r\n';
        footor += '--'+boundary;
        footor += '\r\n';
        footor += 'Content-Disposition: form-data; name="attachname"';
        footor += '\r\n\r\n';
        footor += attach.name;
        footor += '\r\n';
        footor += '--'+boundary+'--';             
        String footorEncoded = EncodingUtil.base64Encode(Blob.valueOf(footor));

        Blob bodyBlob = null;
        String last4Bytes = bodyEncoded.substring(bodyEncoded.length()-4,bodyEncoded.length());
        if(last4Bytes.endsWith('='))
        {
                Blob decoded4Bytes = EncodingUtil.base64Decode(last4Bytes);
                HttpRequest tmp = new HttpRequest();
                tmp.setBodyAsBlob(decoded4Bytes);
                String last4Bytesfootor = tmp.getBody()+footor;   
                bodyBlob = EncodingUtil.base64Decode(headerEncoded+bodyEncoded.substring(0,bodyEncoded.length()-4)+EncodingUtil.base64Encode(Blob.valueOf(last4Bytesfootor)));
        }
        else
        {
                bodyBlob = EncodingUtil.base64Decode(headerEncoded+bodyEncoded+footorEncoded);
        }

        req = new HttpRequest();
        req.setHeader('Content-Type','multipart/form-data; boundary=' + boundary);
        req.setMethod('POST');
        req.setEndpoint('https://' + endPoint);
        req.setBodyAsBlob(bodyBlob);
        req.setTimeout(120000);
    
        http = new Http();
        res = http.send(req);

    } 

ApexでawsへファイルUpload

    public Integer fileUpload(Attachment file){

        String attachmentBodyEncoded = EncodingUtil.base64Encode(file.Body);
        String formattedDateString = Datetime.now().formatGMT('EEE, dd MMM yyyy HH:mm:ss z');
        String key = awsAccessKey;
        String secret = awsSecretAccessKey;
        String bucketname = awsBucket;
        String host = awsService + '-' + awsReign + '.amazonaws.com'; 
        String method = 'PUT';
        String fileNameEncoded	= EncodingUtil.urlEncode(file.Name, 'UTF-8');

        HttpRequest req = new HttpRequest();
        req.setMethod(method);
        req.setEndpoint('https://' + bucketname + '.' + host + '/' + bucketname + '/' + fileNameEncoded);
        req.setHeader('Host', bucketname + '.' + host);
        req.setHeader('Content-Length', String.valueOf(attachmentBodyEncoded.length()));
        req.setHeader('Content-Encoding', 'UTF-8');
        req.setHeader('Content-type', file.ContentType);
        req.setHeader('Connection', 'keep-alive');
        req.setHeader('Date', formattedDateString);
        req.setHeader('ACL', 'public-read-write');
        req.setBodyAsBlob(EncodingUtil.base64Decode(attachmentBodyEncoded));
         
        String stringToSign = 'PUT\n\n' +
        file.ContentType + '\n' +
        formattedDateString + '\n' +
        '/' + bucketname + '/' + bucketname + '/' + fileNameEncoded;
         
        Blob mac = Crypto.generateMac('HMACSHA1', blob.valueof(stringToSign),blob.valueof(secret));
        String signed = EncodingUtil.base64Encode(mac);
        String authHeader = 'AWS' + ' ' + key + ':' + signed;
        req.setHeader('Authorization',authHeader);
         
        Http http = new Http();
        HTTPResponse res = http.send(req);

        return res.getStatusCode();

    }

Apexで選択リスト取得

//取引先の種別の選択リスト取得
List<Schema.PicklistEntry> picklist = getPicklist('Account', 'Type');

for(Schema.PicklistEntry pick : picklist){
    System.debug('-----------------');
    System.debug('Label :' + pick.getLabel());
    System.debug('Value :' + pick.getValue());
    System.debug('Active:' + pick.isActive());
}

//有効な選択リスト取得
public List<Schema.PicklistEntry> getPicklist(String sObjName, String fieldName){
    List<Schema.PicklistEntry> pickList;
    Schema.SObjectType sObjType = (Schema.SObjectType) Schema.getGlobalDescribe().get(sObjName);
    if(sObjType != null){
        Map<String, Schema.SObjectField> fieldmap = sObjType.getDescribe().fields.getMap();
        Schema.SObjectField f = (Schema.SObjectField) fieldmap.get(fieldName);
        if(f != null){
            Schema.DescribeFieldResult r = f.getDescribe();
            pickList = r.getPicklistValues();
            System.debug('pickList' + pickList);
        }
    }
    return pickList;
}

Bad Request

400 Bad Request

HyperText Transfer Protocol (HTTP) の 400 Bad Request レスポンスステータスコードは、何らかのクライアント側のエラーであると分かったために、サーバーがそのリクエストを処理しない (できない) ことを表します (例えば、リクエストの構文が正しくない、リクエストメッセージのフレーミングが無効、リクエスト経路に偽りがあるなど)。

データローダプロセスの設定パラメータ

https://developer.salesforce.com/docs/atlas.ja-jp.dataLoader.meta/dataLoader/loader_params.htm