Camel Components

PDF

Since Camel 2.16

Only producer is supported

The PDF component provides the ability to create, modify or extract content from PDF documents. This component uses Apache PDFBox as the underlying library to work with PDF documents.

To use the PDF component, Maven users will need to add the following dependency to their pom.xml:

pom.xml

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-pdf</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

The PDF component only supports producer endpoints.

pdf:operation[?options]

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

The following two sections list all the options, firstly for the component followed by the endpoint.

Component Options

The PDF component supports the following options which are listed below.

Name Description Default Type

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

Endpoint Options

The PDF endpoint is configured using URI syntax:

pdf:operation

With the following path and query parameters:

Path Parameters

Name Description Default Type

operation (producer)

Required Operation type.

Enum values:

  • create

  • append

  • extractText

  • merge

PdfOperation

Query Parameters

Name Description Default Type

font (producer)

Font.

Enum values:

  • COURIER

  • COURIER_BOLD

  • COURIER_OBLIQUE

  • COURIER_BOLD_OBLIQUE

  • HELVETICA

  • HELVETICA_BOLD

  • HELVETICA_OBLIQUE

  • HELVETICA_BOLD_OBLIQUE

  • TIMES_ROMAN

  • TIMES_BOLD

  • TIMES_ITALIC

  • TIMES_BOLD_ITALIC

  • SYMBOL

  • ZAPF_DINGBATS

HELVETICA

String

fontSize (producer)

Font size in pixels.

14

float

marginBottom (producer)

Margin bottom in pixels.

20

int

marginLeft (producer)

Margin left in pixels.

20

int

marginRight (producer)

Margin right in pixels.

40

int

marginTop (producer)

Margin top in pixels.

20

int

pageSize (producer)

Page size: LETTER, LEGAL or A0 to A6. The older names PAGE_SIZE_A0 to PAGE_SIZE_A6 and PAGE_SIZE_LETTER are also accepted.

Enum values:

  • LETTER

  • LEGAL

  • A0

  • A1

  • A2

  • A3

  • A4

  • A5

  • A6

A4

String

textProcessingFactory (producer)

Text processing to use. autoFormatting: Text is getting sliced by words, then max amount of words that fits in the line will be written into pdf document. With this strategy all words that doesn’t fit in the line will be moved to the new line. lineTermination: Builds set of classes for line-termination writing strategy. Text getting sliced by line termination symbol and then it will be written regardless it fits in the line or not.

Enum values:

  • autoFormatting

  • lineTermination

lineTermination

TextProcessingFactory

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

Message Headers

The PDF component supports the following message header(s), which is/are listed below:

Name Description Default Type

CamelPdfProtectionPolicy (producer)

Constant: PROTECTION_POLICY_HEADER_NAME

Expected type is https://pdfbox.apache.org/docs/2.0.13/javadocs/org/apache/pdfbox/pdmodel/encryption/ProtectionPolicy.htmlProtectionPolicy. If specified then PDF document will be encrypted with it.

ProtectionPolicy

CamelPdfDocument (producer)

Constant: PDF_DOCUMENT_HEADER_NAME

Mandatory header for append operation and ignored in all other operations. Expected type is https://pdfbox.apache.org/docs/2.0.13/javadocs/org/apache/pdfbox/pdmodel/PDDocument.htmlPDDocument. Stores PDF document which will be used for append operation.

PDDocument

CamelPdfDecryptionMaterial (producer)

Constant: DECRYPTION_MATERIAL_HEADER_NAME

Expected type is https://pdfbox.apache.org/docs/2.0.13/javadocs/org/apache/pdfbox/pdmodel/encryption/DecryptionMaterial.htmlDecryptionMaterial. Mandatory header if PDF document is encrypted.

DecryptionMaterial

CamelPdfFilesToMerge (producer)

Constant: FILES_TO_MERGE_HEADER_NAME

Mandatory header for merge operation and ignored in all other operations. The list of pdf files that will be merged, each given as a java.io.File or a java.nio.file.Path.

List

Message Body

The message body at each side of the PDF component: Consumer is the body of the messages the consumer creates, Consumer reply the bodies a consumer that answers its caller can reply with, Producer input the bodies the producer can send or write, and Producer output the body after the producer.

Side Body Description

Producer input

text, bytes, stream or file

The text to write for create and append, which takes the document from the CamelPdfDocument header; a Map or a POJO is written as its toString: marshal it first. extractText reads a PDF from bytes, such as the ByteArrayOutputStream of create, a stream, a file or a PDDocument, not from text; another body, or none, fails. merge takes the files from the CamelPdfFilesToMerge header.

  • With operation=extractText: bytes, stream, file or pojo

  • With operation=merge: any

Producer output

bytes (java.io.ByteArrayOutputStream)

The PDF of create, append and merge as bytes, in a ByteArrayOutputStream, which extractText reads as it is. The text of the document for extractText.

  • With operation=extractText: text (java.lang.String)

The bodies are the ones with the default options. A side that is not listed is not known, and tooling does not guess it. The carriers are described in the Camel Catalog.

Usage

Type converter

Since Camel 4.8, the component is capable of doing simple document conversions. For instance, suppose you are receiving a PDF byte as a byte array:

  • Java

  • XML

  • YAML

from("direct:start")
    .to("pdf:extractText")
    .to("mock:result");
<route>
  <from uri="direct:start"/>
  <to uri="pdf:extractText"/>
  <to uri="mock:result"/>
</route>
- route:
    from:
      uri: direct:start
      steps:
        - to:
            uri: pdf:extractText
        - to:
            uri: mock:result

It is now possible to get the body as a PD Document by using PDDocument doc = exchange.getIn().getBody(PDDocument.class);, which saves the trouble of converting the byte-array to a document.

The type converter reads a PDF from a byte[], a ByteArrayOutputStream, an InputStream, a java.io.File or a java.nio.file.Path. The create, append and merge operations leave the PDF in a ByteArrayOutputStream, so pdf:create can be followed by pdf:extractText directly. The extractText operation fails with an InvalidPayloadException naming the type of the body when the body is missing or is not one of these types.

this only works for unprotected PDF files. For password-protected, the files still need to be converted manually.

Creating a PDF from text

The create operation needs a body with the text to write; without a body it fails with an InvalidPayloadException.

With the default textProcessingFactory=lineTermination, the text is written line by line: a line ends at \r\n, \r or \n. A tab is written as four spaces, and other control characters, which the fonts cannot show, are left out.

The pageSize option takes LETTER, LEGAL or A0 to A6 (default A4). The older names PAGE_SIZE_A0 to PAGE_SIZE_A6 and PAGE_SIZE_LETTER are still accepted. An unknown value fails when the endpoint is created.

Merging PDF files

The merge operation reads the files to merge from the CamelPdfFilesToMerge header: a list of at least two elements, each a java.io.File or a java.nio.file.Path.