Tham khảo tài liệu 'jasperreports for java developers- p4', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Chapter 6 try connection jdbc mysql localhost 3306 flightstats user dbuser password secret reportStream servletOutputStream new HashMap connection application pdf catch Exception e display stack trace in the browser StringWriter stringwriter new StringWriter Printwriter printwriter new PrintWriter stringWriter printWriter text plain .print In the above code there is nothing that we haven t seen before. The logic to add report expressions is encapsulated in the JRXML template. After deploying this servlet and directing the browser to its URL we should see a report similar to the following 139 Report Layout and Design Adding multiple columns to a report JasperReports allows us to generate reports with multiple columns. Reports we have seen so far seem to have multiple columns. For example the report we created in the previous section has a column for model another column for tail number and one more for serial number. However all three of these fields are laid out in a single band element. When we add multiple columns to a report we should think of the data inside a band as a cell regardless of how the data is laid out inside that band. The flightstats database we used for the examples in Chapter 4 Creating Dynamic Reports from Databases contains the country state and city where an aircraft is registered. Let s create a report displaying the tail number of all aircraft registered in the state of New York in the United States. Our report will display the data in three columns. The following JRXML template will generate a report with the desired layout xml version encoding UTF-8 jasperReport xmlns http jasperreports xmlns xsi http 2001 .
