JasperReport 使用JavaBean最为数据源出错，请高手解答！
我是按照JasperReport for Java Developers.pdf来做的
public class FirstReportAction extends DispatchAction {
 
private JRDateSource createReportDataSource() {
JRBeanCollectionDataSource dataSource;
Collection reportRows=initlializeBeanCollection();
dataSource=new JRBeanCollectionDataSource(reportRows);
return dataSource;
}


@SuppressWarnings("unchecked")
private Collection initlializeBeanCollection(){
ArrayList reportRows=new ArrayList();
reportRows.add(new OuserBO("1","2","3"));
return reportRows;
}

@SuppressWarnings("unchecked")
public ActionForward first(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) throws IOException {

ServletOutputStream servletOutputStream = response.getOutputStream();
InputStream reportStream = this.getServlet().getServletConfig().getServletContext()
.getResourceAsStream("/reports/ka.jasper");
 
try
{
JRDateSource dataSource=createReportDataSource();
JasperRunManager.runReportToPdfStream(reportStream, servletOutputStream,new HashMap  
  (),dataSource);
servletOutputStream.flush();
servletOutputStream.close();  
  }



错误：
private JRDateSource createReportDataSource()行报错如下：
JRDateSource cannot be resolved to a type

JRDateSource dataSource=createReportDataSource()行报错如下
 JRDateSource cannot be resolved to a type
 The method createReportDataSource() is undefined for the type FirstReportAction  
 
请问是什么原因？
 
 

------解决方案--------------------
createReportDataSource() is undefined 

方法没有定义啊,复制别人的代码而不理解是永远学不好JAVA的.
------解决方案--------------------
有没有导入包啊?
import net.sf.jasperreports.engine.JRDataSource; 
import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;