All these methods are discussed in this tutorial.

JReport's Client/Server system allows you to view reports via Internet or Intranet.  In this configuration, JReport Viewer and JReport Server typically run as separate programs on different computers connected in a network.   (Note that however, you can also run them on the same computer during testing of your reports.)  The Viewer sends out a request to the Server.  The Server will run the report and then send the report results that are requested by the Viewer. 

For this example, we selected the invoice report from the Tutorial catalog on the Server.  Thus we are requesting the Server to run the invoice report Remotely. 

Step 4: Once the result is available, the following window will appear.



You can use the arrow buttons or the numbers to scroll through the reports.   The Refresh button will reload the reports within a catalog file in case there are changes be made.    

In order to make the JReport Viewer easier to be called from user's Java application, the Viewer program is also provided as a Java Bean.  The JReport Viewer Bean can send a request from a client workstation to the Server and instruct the Server to run a report and return results to the Viewer.

Setting up the JReport Viewer Bean

The first thing you need to do is download the jvbean.zip file from Jinfonet web site.  Inside the jvbean.zip file, there are 5 files.  The Sample1.java and Sample2.java files are examples on how to run the JReport Viewer Bean.  Do not just compile and run these files since they contain constants that need to be adjusted for your installed environment.

The file JRViewer.zip should be used when compiling your program which will call the JReport View Bean.  The JRViewer.zip file should also be used when you run your application which calls JReport View Bean. 

There are three methods to invoke the JReport View Bean, depending on how much control your application requires:

1. One Step Viewer - Your application calls the Viewer, which will get report parameters from the user through a pop-up dialog.
2. Two Step Viewer - Your application calls the Viewer, which returns the number of parameters needed.  Your program then calls Viewer again and provide it with the required parameters.
3. Second Step Viewer - Your application already knows the parameters and calls the Viewer directly in one step.

If you know which method you will use at run time, instead of using the JRViewer.zip file, you can use one of the other two (smaller) jar files (OneStepJRViewer.jar and TwoStepsJRViewer.jar).  The following sections show how to use each of the two methods.

Please note that regardless which method you use, getStatus () should be called each time after calling the Viewer Java beans.  If the return string is "OK", the request is accepted, otherwise an error message is returned.

The First Method: One Step JReport Viewer

In this first method, the user's Java applications will call the Java bean JRDirectViewer and provide the following properties:

1. setServerName ("theSevrerName");
2. setPort ("thePortNumber");
3. setReportName ("theReportName");
4. setCatName ("theCatalogName");
5. setLoadReport ("Yes/No");

After the Java bean JRDirectViewer is loaded, it will ask the JReport Server to run the report and pop up a dialog on the screen to ask the user to input the report parameter, if needed.  This method of invoking the JReport Viewer Bean has the advantage that it does not require the user's Java application to provide the report parameters.  The disadvantage is that it will display a dialog on the screen to ask user to input the report parameters.

After the Viewer have successfully received the report results, you may want to have them printed.  There are also two methods available for printing reports.   They are:

1. printReport ()
2. getPrintStatus ()

Printing is initiated by calling the method printReport ().   While the report is being printed, you can call the getPrintStatus () method to get the current status of the print job.  The return values of the getPrintStatus () are:

1. "No Print Job"
2. "Busy"
3. "OK"
4. Other error messages if there is an error.

Please note that these two printing methods are also available to the second method of calling JReport Viewer Bean described below.


The Second Method: Two Steps JReport Viewer

The second method of invoking the JReport Viewer Bean is that the user's Java application first calls a Java bean named JRPrepareViewer with the following properties:

1. setServerName ("theSevrerName")
2. setPort ("thePortNumber")
3. setReportName ("theReportName")
4. setCatName ("theCatalogName")
5. setLoadReport ("Yes/No")

The JRPrepareViewer Java Bean will return a vector which contains the information about the report. The user's Java application should prepare the parameters based on the information provided by the vector.  The data type of the parameters may be obtained by calling the method getReportParams () which returns a vector. The size of the vector depends on the number of the parameters needed by the report.  Each element in the vector contains the type of one parameter. You can use getType () method to get it.  The following are the types of parameters available:

1. STRING:
2. NUMBER:
3. CURRENCY:
4. BOOLEAN:
5. DATE:
6. TIME:
7. DATETIME:

After the parameters are prepared, you will then call the second Java bean named JRRunViewer with the following properties:

1. setServerName ("theSevrerName")
2. setPort ("thePortNumber")
3. setReportName ("theReportName")
4. setCatName ("theCatalogName")
5. setLoadReport ("Yes/No")
6. setParameters ("Parameters")

In the second method of invoking the JReport Viewer Bean, our bean will not display any dialog on the screen.  However, the user's Java application has to provide all the necessary information and retain full control to the screen.  We note that there is a lot of redundant parameters in the two calls.  This will be improved in a future version.

The Third Method: Second Step JReport Viewer

This method is identical to the second step of the Two Step method above.   After the parameters are prepared, you simply call the second step of the second Java bean named JRRunViewer with the required properties:

1. setServerName ("theSevrerName")
2. setPort ("thePortNumber")
3. setReportName ("theReportName")
4. setCatName ("theCatalogName")
5. setLoadReport ("Yes/No")
6. setParameters ("Parameters")

The example program Sample1 and  Sample2 illustrate how to call JReport Viewer Beans.  Please refer to it for further details.