如何在Jasper报表中动态显示列？

Question

I am generating a Jasper Report, which has 5 fixed columns. The client has requested the ability to select the number of columns at run time.

For example if he checks 2 columns from a displayed JTable then there should be 2 columns in Jasper report, if he checks 4 then there should be four columns in jasper report. To try to solve this I am thinking of adding condition in jasper report. If the client selects column A and BI will set that as a parameter in the report and use that to determine whether to display the column.

In order to do these, I need to use conditions in the Jasper XML. Where should I set the conditions in the report.

Answer 1

You can try the following

1. Create a HashMap and set the required properties in it

    Map params = new HashMap(); params.put("DISPLAY_COLUMN_ONE", "Y") 

2. Pass this params map to Jasper in the method

   JasperFillManager.fillReport

3. In your JRXML, create a parameter corresponding to each property set in the hashmap above:

   <parameter name="DISPLAY_COLUMN_ONE" class="java.lang.String"/>

4. Display the columns based on the parameter value

   <printWhenExpression><![CDATA[$P{DISPLAY_COLUMN_ONE}.equals("Y")]]></printWhenExpression>

Answer 2

you should pass columnCount parameter to jasper and check condition in each column's Print when Expression .

first column Print when Expression is

$P{columnCount} >=1

Second column Print when Expression is

$P{columnCount} >=2

Third column Print when Expression is

$P{columnCount} >=3

Fourth column Print when Expression is

$P{columnCount} >=4

Hope this help you.

Answer 3

I would just make multiple copies of your jasper report, one for each variation of number of columns. It may be a lot of redundancy, but it's very easy as long as the number of possible variations isn't too high. The report you end up calling depends on the user's selection.

I can't think of any way of varying the columns within a report based on a conditional.