我尝试创建动态交叉表。当我尝试时，我有一个错误java.lang.ClassCastException Jasper Report Crosstab，而不是我解决它。但是我的报告是空的。我不明白为什么。我检查我的结果集是否为空。但它不为空。
这是我的代码：
public class DynamicJasperTemplate{
.....//variables define here
public void buildReport() throws Exception{
....//I create query here and get row column and measure field name
JRDataSource ds = getDataSource(query,a,b,c);//I get data from db as jrdatasource
DynamicReport dr = buildReportLayout(a,b,c,ds); // build report layout and add it crosstab in this method.
params.put("sr",ds);//I set report parameter value
JasperReport jr = DynamicJasperHelper.generateJasperReport(dr, new ClassicLayoutManager(), params);
JasperPrint jp = JasperFillManager.fillReport(jr, params, ds);
JasperExportManager.exportReportToPdfFile(jp,"C:/report-out.pdf");
}
private DynamicReport buildReportLayout(String[] a,String[] b,String[] c, JRDataSource ds) {
FastReportBuilder drb = new FastReportBuilder();
drb.setWhenNoDataAllSectionNoDetail();
initStyles();
CrosstabBuilder cb = new CrosstabBuilder();
cb.setHeight(200)
.setWidth(500)
.setHeaderStyle(mainHeaderStyle)
.setDatasource("sr",DJConstants.DATA_SOURCE_ORIGIN_REPORT_DATASOURCE, DJConstants.DATA_SOURCE_TYPE_JRDATASOURCE)
.setUseFullWidth(true)
.setColorScheme(4)
.setAutomaticTitle(true)
.setCellBorder(Border.PEN_1_POINT());
Object obj="NUMBER";
Object obj1="VARCHAR2";
String type = null;
for(int i=0; i<a.length; i++) {
DJCrosstabRow row = new CrosstabRowBuilder().setProperty(a[i],String.class.getName())
.setHeaderWidth(100).setHeight(0)
.setTitle(a[i])
.setShowTotals(true).setTotalStyle(totalStyle)
.setTotalHeaderStyle(totalHeader).setHeaderStyle(colAndRowHeaderStyle)
.build();
cb.addRow(row);
}
DJCrosstabColumn col =new CrosstabColumnBuilder().setProperty(b.toString(),"java.sql.Timestamp")
.setHeaderHeight(60).setWidth(50)
.setTitle(b.toString()).setShowTotals(true)
.setTotalStyle(totalStyle).setTotalHeaderStyle(totalHeader)
.setHeaderStyle(colAndRowHeaderStyle)
.build();
cb.addColumn(col);
cb.addMeasure(c[0],"java.math.BigDecimal", DJCalculation.NOTHING , c[0],measureStyle);
djcross = cb.build();
drb.addHeaderCrosstab(djcross);
drb.setUseFullPageWidth(true);
drb.addParameter("sr", "java.util.Collection");
DynamicReport dr = drb.build();
return dr;
}
private void initStyles() {
....//here ı define styles
}
private JRDataSource getDataSource(String query,String[] a,String[] b,String[] c) throws SQLException, JRException {
Connection con = new getConnection().conn();
List<Map<String, ?>> arr = new ArrayList<Map<String, ?>>();
String columnValue;
Map data = new HashMap();
JRResultSetDataSource result = null;
ResultSet rs = null;
int i;
try{
if(con!=null){
Statement stmt = con.createStatement();
rs = stmt.executeQuery(query);
JRDataSource ds = new JRResultSetDataSource(rs);
return ds;
}
......
我希望你能告诉我我做错了什么。