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Blob Class

Contains methods for the Blob primitive data type.

Namespace

System

Usage

Salesforce supports Blob manipulation only with Apex class methods that are supplied by Salesforce. For more information on Blobs, see Primitive Data Types.

Blob Methods

The following are methods for Blob.

size()

Returns the number of bytes in the Blob.

Signature

public Integer size()

Return Value

Type: Integer

Example

String myString = 'StringToBlob';
Blob myBlob = Blob.valueof(myString);
Integer size = myBlob.size();

toPdf(stringToConvert)

Creates a binary object out of the given string, encoding it as a PDF file.

Signature

public static Blob toPdf(String stringToConvert)

Parameters

  • stringToConvert:

    Type: String

Return Value

Type: Blob

Usage

Blob.toPDF(stringToConvert) works with any string value. Since the Spring ’26 release, Blob.toPDF() uses the same PDF rendering service as Visualforce.

See Render a Visualforce Page as a PDF File for details of the improved PDF rendering service, including considerations and limitations for rendering PDF files.

The Visualforce PDF rendering service expands the range of fonts available, and includes a multibyte-capable font. The default font is serif, which is a change from the default sans-serif used by Blob.toPDF(). See Fonts Available When Using Visualforce PDF Rendering.

Example

String pdfContent = 'This is a test string';
Account a = new account(name = 'test');
insert as user a;
Attachment attachmentPDF = new Attachment();
attachmentPdf.parentId = a.id;
attachmentPdf.name = a.name + '.pdf';
attachmentPdf.body = Blob.toPDF(pdfContent);
insert as user attachmentPDF;

toString()

Casts the Blob into a String.

Signature

public String toString()

Return Value

Type: String

Example

String myString = 'StringToBlob';
Blob myBlob = Blob.valueof(myString);
Assert.areEqual('StringToBlob', myBlob.toString());

valueOf(stringToBlob)

Casts the specified String to a Blob.

Signature

public static Blob valueOf(String stringToBlob)

Parameters

Return Value

Type: Blob

Example

String myString = 'StringToBlob';
Blob myBlob = Blob.valueof(myString);