Programmatically Assembling PDF Documents

You can use the Assembler Service API to assemble multiple PDF documents into a single PDF document. The following illustration shows three PDF documents being merged into a single PDF document.

To assemble two or more PDF documents into a single PDF document, you need a DDX document. A DDX document describes the PDF document that the Assembler service produces. That is, the DDX document instructs the Assembler service what actions to perform.

For the purpose of this discussion, assume that the following DDX document is used.

<?xml version="1.0" encoding="UTF-8"?> 
<DDX xmlns="http://ns.adobe.com/DDX/1.0/"> 
    <PDF result="out.pdf"> 
        <PDF source="map.pdf" /> 
        <PDF source="directions.pdf" /> 
    </PDF> 
</DDX>

This DDX document merges two PDF documents named map.pdf and directions.pdf into a single PDF document.

Note: To see a DDX document that disassembles a PDF document, see Programmatically Disassembling PDF Documents.
Note: For more information about the Assembler service, see Services Reference for LiveCycle.
Note: For more information about a DDX document, seeAssembler Service and DDX Reference.

Considerations when invoking Assembler service using web services

When you add headers and footers during the assembling of large documents, you may encounter an OutOfMemory error and the files will not be assembled. To reduce the chance of this problem occurring, add a DDXProcessorSetting element to your DDX document, as shown in the following example.

<DDXProcessorSetting name="checkpoint" value="2000" />

You can add this element as a child of the DDX element or as a child of a PDF result element. The default value for this setting is 0 (zero), which turns checkpointing off and the DDX behaves as if the DDXProcessorSetting element is not present. If you have encountered an OutOfMemory error, you may need to set the value to an integer, typically between 500 and 5000. A small checkpoint value results in more frequent checkpointing.

Summary of steps

To assemble a single PDF document from multiple PDF documents, perform the following tasks:

  1. Include project files.

  2. Create a PDF Assembler client.

  3. Reference an existing DDX document.

  4. Reference input PDF documents.

  5. Set run-time options.

  6. Assemble the input PDF documents.

  7. Extract the results.

Include project files

Include the necessary files in your development project. If you are creating a client application by using Java, include the necessary JAR files. If you are using web services, ensure that you include the proxy files.

The following JAR files must be added to your project’s class path:

  • adobe-livecycle-client.jar

  • adobe-usermanager-client.jar

  • adobe-assembler-client.jar

  • adobe-utilities.jar (required if LiveCycle is deployed on JBoss)

  • jbossall-client.jar (required if LiveCycle is deployed on JBoss)

if LiveCycle is deployed on a supported J2EE application server other than JBoss, you must replace the adobe-utilities.jar and jbossall-client.jar files with JAR files that are specific to the J2EE application server on which LiveCycle is deployed.

Create a PDF Assembler client

Before you can programmatically perform an Assembler operation, you must create an Assembler client.

Reference an existing DDX document

A DDX document must be referenced to assemble a PDF document. For example, consider the DDX document that was introduced in this section. This DDX document instructs the Assembler service to merge two PDF documents into a single PDF document.

Reference input PDF documents

Reference input PDF documents that you want to pass to the Assembler service. For example, if you want to pass two input PDF documents named Map and Directions, you must pass the corresponding PDF files.

Both the map.pdf file and the directions.pdf file must be placed in a collection object. The name of the key must match the value of the PDF source attribute in the DDX document. It does not matter what the name of the PDF file is if the key and the source attribute in the DDX document match.

Note: An AssemblerResult object, which contains a collection object, is returned if you invoke the invokeDDX operation. This operation is used when you pass two or more input PDF documents to the Assembler service. However, if you pass only one input PDF to the Assembler service and expect only one return document, invoke the invokeOneDocument operation. When invoking this operation, a single document is returned. For information about using this operation, see Assembling Encrypted PDF Documents.

Set run-time options

You can set run-time options that control the behaviour of the Assembler service while it performs a job. For example, you can set an option that instructs the Assembler service to continue processing a job if an error is encountered. For information about the run-time options that you can set, see the AssemblerOptionSpec class reference in LiveCycle API Reference.

Assemble the input PDF documents

After you create the service client, reference a DDX file, create a collection object that stores input PDF documents, and set run-time options, you can invoke the DDX operation. When using the DDX document specified in this section, the map.pdf and direction.pdf files are merged into one PDF document.

Extract the results

The Assembler service returns a java.util.Map object, which can be obtained from the AssemblerResult object, and that contains operation results. The returned java.util.Map object contains the resultant documents and any exceptions.

The following table summarizes some of the key values and object types that can be located in the returned java.util.Map object.

Key value

Object type

Description

documentName

com.adobe.idp.Document

Contains the resultant documents that are specified in a DDX resultant element

documentName

Exception

Contains any exception for the document

OutputMapConstants.LOG_NAME

com.adobe.idp.Documen

Contains the job log

Assemble PDF documents using the Java API

Assemble a PDF document by using the Assembler Service API (Java):

  1. Include project files.

    Include client JAR files, such as adobe-assembler-client.jar, in your Java project’s class path.

  2. Create a PDF Assembler client.

    • Create a ServiceClientFactory object that contains connection properties.

    • Create an AssemblerServiceClient object by using its constructor and passing the ServiceClientFactory object.

  3. Reference an existing DDX document.

    • Create a java.io.FileInputStream object that represents the DDX document by using its constructor and passing a string value that specifies the location of the DDX file.

    • Create a com.adobe.idp.Document object by using its constructor and passing the java.io.FileInputStream object.

  4. Reference input PDF documents.

    • Create a java.util.Map object that is used to store input PDF documents by using a HashMap constructor.

    • For each input PDF document, create a java.io.FileInputStream object by using its constructor and passing the location of the input PDF document.

    • For each input PDF document, create a com.adobe.idp.Document object and pass the java.io.FileInputStream object that contains the PDF document.

    • For each input document, add an entry to the java.util.Map object by invoking its put method and passing the following arguments:

      • A string value that represents the key name. This value must match the value of the PDF source element specified in the DDX document.

      • A com.adobe.idp.Document object (or java.util.List object that specifies multiple documents) that contains the source PDF document.

  5. Set run-time options.

    • Create an AssemblerOptionSpec object that stores run-time options by using its constructor.

    • Set run-time options to meet your business requirements by invoking a method that belongs to the AssemblerOptionSpec object. For example, to instruct the Assembler service to continue processing a job when an error occurs, invoke the AssemblerOptionSpec object’s setFailOnError method and pass false.

  6. Assemble the input PDF documents.

    Invoke the AssemblerServiceClient object’s invokeDDX method and pass the following required values:

    • A com.adobe.idp.Document object that represents the DDX document to be used

    • A java.util.Map object that contains the input PDF files to be assembled

    • A com.adobe.livecycle.assembler.client.AssemblerOptionSpec object that specifies the run-time options, including default font and job log level

    The invokeDDX method returns a com.adobe.livecycle.assembler.client.AssemblerResult object that contains the results of the job and any exceptions that occurred.

  7. Extract the results.

    To obtain the newly created PDF document, perform the following actions:

    • Invoke the AssemblerResult object’s getDocuments method. This returns a java.util.Map object.

    • Iterate through the java.util.Map object until you find the resultant com.adobe.idp.Document object. (You can use the PDF result element specified in the DDX document to get the document.)

    • Invoke the com.adobe.idp.Document object’s copyToFile method to extract the PDF document.

    Note: If LOG_LEVEL was set to produce a log, you can extract the log by using the AssemblerResult object's getJobLog method.

Assemble PDF documents using the web service API

Assemble PDF documents by using the Assembler Service API (web service):

  1. Include project files.

    Create a Microsoft .NET project that uses MTOM. Ensure that you use the following WSDL definition: http://localhost:8080/soap/services/AssemblerService?WSDL&lc_version=9.0.1.

    Note: Replace localhost with the IP address of the server hosting LiveCycle.
  2. Create a PDF Assembler client.

    • Create an AssemblerServiceClient object by using its default constructor.

    • Create an AssemblerServiceClient.Endpoint.Address object by using the System.ServiceModel.EndpointAddress constructor. Pass a string value that specifies the WSDL to the LiveCycle service (for example, http://localhost:8080/soap/services/AssemblerService?blob=mtom). You do not need to use the lc_version attribute. This attribute is used when you create a service reference.

    • Create a System.ServiceModel.BasicHttpBinding object by getting the value of the AssemblerServiceClient.Endpoint.Binding field. Cast the return value to BasicHttpBinding.

    • Set the System.ServiceModel.BasicHttpBinding object’s MessageEncoding field to WSMessageEncoding.Mtom. This value ensures that MTOM is used.

    • Enable basic HTTP authentication by performing the following tasks:

      • Assign the LiveCycle user name to the field AssemblerServiceClient.ClientCredentials.UserName.UserName.

      • Assign the corresponding password value to the field AssemblerServiceClient.ClientCredentials.UserName.Password.

      • Assign the constant value HttpClientCredentialType.Basic to the field BasicHttpBindingSecurity.Transport.ClientCredentialType.

      • Assign the constant value BasicHttpSecurityMode.TransportCredentialOnly to the field BasicHttpBindingSecurity.Security.Mode.

  3. Reference an existing DDX document.

    • Create a BLOB object by using its constructor. The BLOB object is used to store the DDX document.

    • Create a System.IO.FileStream object by invoking its constructor and passing a string value that represents the file location of the DDX document and the mode in which to open the file.

    • Create a byte array that stores the content of the System.IO.FileStream object. You can determine the size of the byte array by getting the System.IO.FileStream object’s Length property.

    • Populate the byte array with stream data by invoking the System.IO.FileStream object’s Read method and passing the byte array, the starting position, and the stream length to read.

    • Populate the BLOB object by assigning its MTOM property with the contents of the byte array.

  4. Reference input PDF documents.

    • For each input PDF document, create a BLOB object by using its constructor. The BLOB object is used to store the input PDF document.

    • Create a System.IO.FileStream object by invoking its constructor and passing a string value that represents the file location of the input PDF document and the mode in which to open the file.

    • Create a byte array that stores the content of the System.IO.FileStream object. You can determine the size of the byte array by getting the System.IO.FileStream object’s Length property.

    • Populate the byte array with stream data by invoking the System.IO.FileStream object’s Read method. Pass the byte array, the starting position, and the stream length to read.

    • Populate the BLOB object by assigning its MTOM field with the contents of the byte array.

    • Create a MyMapOf_xsd_string_To_xsd_anyType object. This collection object is used to store input PDF documents.

    • For each input PDF document, create a MyMapOf_xsd_string_To_xsd_anyType_Item object. For example, if two input PDF documents are used, create two MyMapOf_xsd_string_To_xsd_anyType_Item objects.

    • Assign a string value that represents the key name to the MyMapOf_xsd_string_To_xsd_anyType_Item object's key field. This value must match the value of the PDF source element specified in the DDX document. (Perform this task for each input PDF document.)

    • Assign the BLOB object that stores the PDF document to the MyMapOf_xsd_string_To_xsd_anyType_Item object's value field. (Perform this task for each input PDF document.)

    • Add the MyMapOf_xsd_string_To_xsd_anyType_Item object to the MyMapOf_xsd_string_To_xsd_anyType object. Invoke the MyMapOf_xsd_string_To_xsd_anyType object's Add method and pass the MyMapOf_xsd_string_To_xsd_anyType object. (Perform this task for each input PDF document.)

  5. Set run-time options.

    • Create an AssemblerOptionSpec object that stores run-time options by using its constructor.

    • Set run-time options to meet your business requirements by assigning a value to a data member that belongs to the AssemblerOptionSpec object. For example, to instruct the Assembler service to continue processing a job when an error occurs, assign false to the AssemblerOptionSpec object’s failOnError data member.

  6. Assemble the input PDF documents.

    Invoke the AssemblerServiceClient object’s invoke method and pass the following values:

    • A BLOB object that represents the DDX document.

    • The mapItem array that contains the input PDF documents. Its keys must match the names of the PDF source files, and its values must be the BLOB objects that correspond to those files.

    • An AssemblerOptionSpec object that specifies run-time options.

    The invoke method returns an AssemblerResult object that contains the results of the job and any exceptions that may have occurred.

  7. Extract the results.

    To obtain the newly created PDF document, perform the following actions:

    • Access the AssemblerResult object’s documents field, which is a Map object that contains the result PDF documents.

    • Iterate through the Map object until you find the key that matches the name of the resultant document. Then cast that array member’s value to a BLOB.

    • Extract the binary data that represents the PDF document by accessing its BLOB object’s MTOM property. This returns an array of bytes that you can write out to a PDF file.

    Note: If LOG_LEVEL was set to produce a log, you can extract the log by getting the value of the AssemblerResult object's jobLog data member.

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