從記錄集中獲取數據並將其存儲在列表中

Question

我正在嘗試讀取和 excel 文件並生成 pdf 報告

我面臨的問題是我能夠從 excel 文件中獲取記錄但無法將其存儲在 ArrayList/List 中

當我打印列表時，它只顯示 Excel 文件的最后一條記錄

    @ManagedBean
    @RequestScoped
    public class testbean {

    private List<test> Testlist = new ArrayList<test>();

        String loc1 = UploadDownloadFileServlet.location;



    public List<test> getTestlist() throws FilloException {

        test t = new test();

            Fillo fillo = new Fillo();
        Connection connection = fillo.getConnection(loc1);
        String strQuery = "select * from Sheet1";
        Recordset recordset = connection.executeQuery(strQuery);
        System.out.println("path "+loc1);
        int k = recordset.getCount();
        System.out.println(k);
        while (recordset.next()) {
            t.setNAME(recordset.getField("NAME"));
            t.setSURNAME(recordset.getField("SURNAME"));
            t.setCITY(recordset.getField("CITY"));
            System.out.println(i);


                    }
                        Testlist.add(t);
            recordset.close();
        connection.close();


        return Testlist;
    }

    public void setLstPersonas(List<test> Testlist) {
        this.Testlist = Testlist;
    }

    public void exportarPDF(ActionEvent actionEvent) throws JRException, IOException, FilloException{
        File jasper = new File(FacesContext.getCurrentInstance().getExternalContext().getRealPath("/newReport.jasper"));
        JasperPrint jasperPrint = JasperFillManager.fillReport(jasper.getPath(),null, new JRBeanCollectionDataSource(this.getTestlist()));



        HttpServletResponse response = (HttpServletResponse) FacesContext.getCurrentInstance().getExternalContext().getResponse();
        response.addHeader("Content-disposition","attachment; filename=jsfReporte.pdf");
        ServletOutputStream stream = response.getOutputStream();

        JasperExportManager.exportReportToPdfStream(jasperPrint, stream);
        stream.flush();
        stream.close();

        FacesContext.getCurrentInstance().responseComplete();           
    }
}

EXCEL中的數據

NAME    SURNAME CITY
JP      SHAH    MUM
RAHUL           BOM
ROHIT   RAUL    DEL
PARTH           BAN
JAY     PIKLE    BEN

PDF 輸出

NAME SURNAME CITY
JAY PIKLE BEN
JAY PIKLE BEN
JAY PIKLE BEN
JAY PIKLE BEN
JAY PIKLE BEN

Answer 1

你應該把 Testlist.add(t); 在你的 while 循環中

Answer 2

改變這個

while (recordset.next()) {
                t.setNAME(recordset.getField("NAME"));
                t.setSURNAME(recordset.getField("SURNAME"));
                t.setCITY(recordset.getField("CITY"));
                System.out.println(i);


                        }
                            Testlist.add(t);

對此

while (recordset.next()) {
            t.setNAME(recordset.getField("NAME"));
            t.setSURNAME(recordset.getField("SURNAME"));
            t.setCITY(recordset.getField("CITY"));
            System.out.println(i);

            // this line should be inside the loop
            Testlist.add(t);

                    }

Answer 3

它是一個列表列表。 TestList 正在進行多項測試。 在向測試添加值之前，不要在公共場合初始化測試，而是在 Whileloop 內初始化。 並將測試添加到 whileloop 中的測試列表。

我有類似的問題。我的是地圖列表。就像你挖掘的最后一條記錄覆蓋以前的記錄並添加新記錄一樣。 當我在 while 循環中初始化地圖時，它得到了解決。