提供的java.sql.Connection对象为null

Question

即时尝试将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,所以我有点迷失..我必须指定连接字符串到数据库或什么？我应该在哪里添加它.

顺便说一下,我正在使用JSF 2,intellij和maven.

谢谢.

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) {

        }

然后在这一行添加连接:

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