Question

我试图将jrxml文件导出为pdf，但我收到此错误：

WARN query.JRJdbcQueryExecuter  - The supplied java.sql.Connection object is null.

我只得到一个空白的pdf文件..

这是我导出为PDF的方法：

public void printReport(ActionEvent event) throws JRException, IOException {

        String reportPath = FacesContext.getCurrentInstance().getExternalContext().getRealPath("/test.jrxml");
        JasperReport report = JasperCompileManager.compileReport(reportPath);
        JasperPrint jasperPrint = JasperFillManager.fillReport(report, new HashMap<String, String>());
        HttpServletResponse httpServletResponse = (HttpServletResponse) FacesContext.getCurrentInstance().getExternalContext().getResponse();
        httpServletResponse.addHeader("Content-disposition", "attachment; filename=report.pdf");
        ServletOutputStream servletOutputStream = httpServletResponse.getOutputStream();
        JasperExportManager.exportReportToPdfStream(jasperPrint, servletOutputStream);
        FacesContext.getCurrentInstance().responseComplete();
    }

我是jasperreports的新手，所以我有点失落..我必须指定连接字符串到de数据库或什么？我应该在哪里添加它。

BTW，我正在使用JSF 2，intellij和maven。

感谢。

Answer 1

我解决了我的问题..我必须为我的报告指定数据库连接！

 Connection conn;
        try {
        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
        conn = DriverManager.getConnection("jdbc:sqlserver://localhost:55334;databaseName=Frutemu;integratedSecurity=true","","");
        } catch (SQLException ex) {
        } catch (ClassNotFoundException ex) {

        }

然后在此行中添加连接：

JasperPrint jasperPrint = JasperFillManager.fillReport(report, new HashMap<String, String>(), conn);

Answer 2

如果要使用Java bean作为源而不是DB连接，则可以这样做以避免异常：

Sub Test()

    GetExcel_INV_Hist "C:\Path_To_My_Workbook\Book1.xlsx"

End Sub

Public Sub GetExcel_INV_Hist(File_Path_Name As String)

    Dim MyXL As Object
    Dim MyWB As Object

    Set MyXL = CreateXL

    Set MyWB = MyXL.Workbooks.Open(File_Path_Name)

    With MyWB.worksheets("Sheet1")
        .Columns("AA:AC").NumberFormat = "$#,##0.00_);[Red]($#,##0.00)"
        .Columns("Z:Z").NumberFormat = "0.00%"

        With .Columns("Z:Z")
            .FormatConditions.Add Type:=2, Formula1:="=$Y1=""GM""" '2 = xlExpression
            .FormatConditions(.FormatConditions.Count).SetFirstPriority
            With .FormatConditions(1)
                .NumberFormat = "$#,##0.00"
            End With
        End With

    End With

End Sub

Public Function CreateXL(Optional bVisible As Boolean = True) As Object

    Dim oTmpXL As Object

    On Error Resume Next
    Set oTmpXL = GetObject(, "Excel.Application")

    If Err.Number <> 0 Then
        Err.Clear
        On Error GoTo ERROR_HANDLER
        Set oTmpXL = CreateObject("Excel.Application")
    End If

    oTmpXL.Visible = bVisible
    Set CreateXL = oTmpXL

    On Error GoTo 0
    Exit Function

ERROR_HANDLER:
        MsgBox "Error " & Err.Number & vbCr & _
            " (" & Err.Description & ") in procedure CreateXL."
End Function

提供的java.sql.Connection对象为null

2 个答案: