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Accessing a PDF Document with the Acrobat Viewer JavaBean

Contents Preliminary Setup Opening a PDF Document    Setting the Layout    Setting the Document to Display    Setting the Viewer Properties    Getting the Current Page    Setting the Zoom Level    Displaying the Document    Using the Viewer Commands Displaying a PDF Document in Acrobat Viewer    Opening a Document    Bookmarking a Document    Selecting Text Conclusion Resources

A PDF document is commonly opened in Acrobat Reader to edit, view, and print. But when you need to open a PDF in a Java application, Acrobat Reader is not accessible. Fortunately, Adobe provides a viewer API, the Acrobat Viewer JavaBean, to view and print PDF documents from Java applications, JavaBeans, or Java applets. The Acrobat classes are provided in the com.adobe.acrobat package of the Acrobat Viewer distribution. In this tutorial, we shall integrate the Acrobat Viewer in a Java application. We'll open an example PDF document in the application with the Acrobat Viewer, and discuss the different features of the Acrobat Viewer.

This tutorial has the following sections:

1. Preliminary Setup
2. Opening a PDF Document
3. Displaying a PDF Document in Acrobat Viewer

Preliminary Setup

The Acrobat Viewer JavaBean API is available from the Acrobat Viewer JavaBean page. Download the bean.zip file. The Acrobat Viewer is available for Windows, Macintosh, Solaris, UNIX, and OS/2 platforms. For the purposes of this tutorial, we'll consider the Acrobat Viewer to be installed on the Windows platform. For installation on other platforms, refer to the installation notes for the specific platform. Extract the bean.zip file to an installation directory. The Acrobat Viewer for JavaBean API classes are included in the %AcrobatViewer%/acrobat.jar file, where the %AcrobatViewer% environment variable represents the directory in which the Acrobat Viewer JavaBean distribution is installed. Add %AcrobatViewer%/acrobat.jar and %AcrobatViewer%/MRJToolkitStubs.zip to the CLASSPATH environment variable.

A Java application with the Acrobat Viewer API may be developed in an IDE such as Eclipse, JDeveloper, or NetBeans, or as a command-line application. In this tutorial, a sample Acrobat Viewer Java application is developed as a command-line application. JRE 1.1.8 or later is recommended for the Acrobat Viewer.

Opening a PDF Document

Having installed the Acrobat Viewer API, we shall open an example PDF document in Acrobat Viewer. The Adobe Document Services PDF document is used as the example document. Store the example PDF document in the C:/Adobe directory.

The Acrobat Viewer for JavaBean API provides methods for displaying a PDF document from a Java application. First, import the com.adobe.acrobat package. Also import the java.awt and java.io packages, which will be used for creating a GUI and loading the PDF file, respectively.

import com.adobe.acrobat.*;
import java.awt.*;
import java.io.*;

Setting the Layout

Create a Frame object, to which the Acrobat Viewer will be added, and set the layout of the frame. Specify BorderLayout as the layout of the frame.

Frame frame = new Frame("PDF Viewer");
frame.setLayout(new BorderLayout());

Viewer viewer = new Viewer();

Add the Viewer object to the frame. Add the Viewer to the center of the frame.

frame.add(viewer, BorderLayout.CENTER);

Setting the Document to Display

Open a FileInputStream to the PDF document that is to be displayed in the Acrobat Viewer.

InputStream input =
    new FileInputStream (new File(
        "C:/Adobe/95004509_AcroDS_SB_UE.pdf"));

Set the FileInputStream as the input to the Acrobat Viewer.

viewer.setDocumentInputStream(input);

A PDF document may also be input with the setDocumentURL(java.lang.String docURL) method.

Setting the Viewer Properties

Acrobat Viewer has several properties to specify the display characteristics of a PDF document. The viewer properties are of two types: static and dynamic. Static properties are set before a viewer is displayed and may not be modified after the viewer is displayed. Dynamic properties may be set and modified after a viewer is displayed. Some of the properties that may be set for the Acrobat Viewer are listed in the following table.

To set the page layout to SinglePage, the zoom type to FitPage, and the magnification to 100 percent, you just make a series of calls to setProperty():

 viewer.setProperty("Default_Page_Layout",
                        "SinglePage");
 viewer.setProperty("Default_Zoom_Type",
                        "FitPage");
 viewer.setProperty("Default_Magnification",
                        "100");

Getting the Current Page

The number of pages in the PDF document and the current page are obtained with the getPageCount() and getCurrentPage() methods. As an example, print out the number of pages in the example document and the current page displayed.

System.out.println("Page Count: "+viewer.getPageCount());
System.out.println("Current Page: "+viewer.getCurrentPage());

Page 0 corresponds to the first page in the document.

Setting the Zoom Level

You can set the zoom level of the current page with the zoomTo() method. Set the zoom magnification to 100 percent by specifying 1.0 as a double in the zoomTo() method.

viewer.zoomTo(1.0);

Displaying the Document

Create the layout of the viewer components and activate the viewer as follows:

viewer.activate();

Next, set the frame size in which the viewer is to be added, and display the frame.

frame.setSize(400, 500);
frame.pack(); 
frame.show();

You'll find the example application PDFViewer.java in the Resources section. Run the Java application in a command-line window. The number of pages for the example PDF document is 3 and the current page is 0, the index of the first page of the PDF document. The example PDF document gets displayed in the Acrobat Viewer. As the zoom level is set to 1.0 in the Java application, the PDF document is displayed with 1.0 magnification. Figure 1 illustrates the PDF document in Acrobat Viewer.

Figure 1. PDF Document in Acrobat Viewer

Using the Viewer Commands

The Acrobat Viewer provides some viewer commands to edit the document and to modify the view characteristics of the document. The viewer commands are specified in the ViewerCommand interface, which is implemented by the Viewer class. To run a viewer command, invoke the execMenuItem(java.lang.String viewerCommand) method of the Viewer class. For example, to run the ZoomTo_K command:

Viewer viewer=new Viewer();
viewer.execMenuItem(ViewerCommand.ZoomTo_K);

Some of the commonly used viewer commands are listed in the following table:

The Acrobat Viewer may be displayed with some of the toolbar buttons removed. For example, you can remove the Open and Open URL buttons in the Acrobat Viewer with:

String[] dis = {ViewerCommand.Open_K, ViewerCommand.OpenURL_K};
Viewer viewer = new Viewer(dis);

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