scheduled-tasks - 在 BIRT API 中处理 JDBC 异常

Question

我有一个基于独立 RunAndRenderTask 的调度程序作业。报告设计连接到远程 mysql 数据库以获取数据。调度程序生成 PDF 并将报告作为附件通过电子邮件发送给一组人。只要数据库可用，这就有效。

但是当数据库不可用时，我可以在日志中看到错误，但是 RunAndRenderTask 仍然会生成一个空白且无用的 PDF 报告，调度程序会通过电子邮件发送该报告。我需要能够捕获此异常，而是向另一组可以解决数据库问题的人员发送电子邮件。我尝试了各种方法，但不知道该怎么做。在下面的代码中，我希望 API 返回异常，因此打印“BirtException”或“Exception”，但即使存在 JDBC 异常，此代码也会打印“Success”。感谢您的帮助。

这是我的代码。

        IReportEngine engine = null;
    IRunAndRenderTask runAndRenderTask = null;

    try  {
        EngineConfig config = new EngineConfig();
        config.setEngineHome("birt-runtime-4_4_0/RuntimeEngine");
        Platform.startup(config);
        IReportEngineFactory factory = (IReportEngineFactory) Platform
                .createFactoryObject(IReportEngineFactory.EXTENSION_REPORT_ENGINE_FACTORY);
        engine = factory.createReportEngine(config);

        IReportRunnable reportRunnable = engine.openReportDesign(DATA_PATH + "sample.rptdesign");
        runAndRenderTask = engine.createRunAndRenderTask(reportRunnable);

        PDFRenderOption option = new PDFRenderOption();
        option.setOutputFileName(DATA_PATH + "output.pdf");
        option.setOutputFormat("pdf");

        runAndRenderTask.setRenderOption(option);
        runAndRenderTask.run();
        System.out.println("Success!");
    } catch (BirtException e) {
        System.out.println("BirtException");
        e.printStackTrace();
    } catch (Throwable e) {
        System.out.println("Exception");
        e.printStackTrace();

    } finally {
        if (runAndRenderTask != null) {
            runAndRenderTask.close();
        }

        if (engine != null) {
            engine.destroy();               
        }
        Platform.shutdown();
        RegistryProviderFactory.releaseDefault();
    }

这是异常堆栈跟踪，它永远不会被 RunAndRenderTask.run() 传回

    INFO: Loaded JDBC driver class in class path: com.mysql.jdbc.Driver
    Jun 26, 2014 9:26:43 PM org.eclipse.birt.data.engine.odaconsumer.ConnectionManager openConnection
    SEVERE: Unable to open connection.
    org.eclipse.birt.report.data.oda.jdbc.JDBCException: There is an error in get connection, Communications link failure

     The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server..
    at org.eclipse.birt.report.data.oda.jdbc.JDBCDriverManager.doConnect(JDBCDriverManager.java:336)
at org.eclipse.birt.report.data.oda.jdbc.JDBCDriverManager.getConnection(JDBCDriverManager.java:235)
at org.eclipse.birt.report.data.oda.jdbc.Connection.connectByUrl(Connection.java:252)
at org.eclipse.birt.report.data.oda.jdbc.Connection.open(Connection.java:162)
at org.eclipse.datatools.connectivity.oda.consumer.helper.OdaConnection.open(OdaConnection.java:250)
at org.eclipse.birt.data.engine.odaconsumer.ConnectionManager.openConnection(ConnectionManager.java:165)
at org.eclipse.birt.data.engine.executor.DataSource.newConnection(DataSource.java:224)
at org.eclipse.birt.data.engine.executor.DataSource.open(DataSource.java:212)
at org.eclipse.birt.data.engine.impl.DataSourceRuntime.openOdiDataSource(DataSourceRuntime.java:217)
at org.eclipse.birt.data.engine.impl.QueryExecutor.openDataSource(QueryExecutor.java:435)
at org.eclipse.birt.data.engine.impl.QueryExecutor.prepareExecution(QueryExecutor.java:322)
at org.eclipse.birt.data.engine.impl.PreparedQuery.doPrepare(PreparedQuery.java:463)
at org.eclipse.birt.data.engine.impl.PreparedDataSourceQuery.produceQueryResults(PreparedDataSourceQuery.java:190)
at org.eclipse.birt.data.engine.impl.PreparedDataSourceQuery.execute(PreparedDataSourceQuery.java:178)
at org.eclipse.birt.data.engine.impl.PreparedOdaDSQuery.execute(PreparedOdaDSQuery.java:178)
at org.eclipse.birt.report.data.adapter.impl.DataRequestSessionImpl.execute(DataRequestSessionImpl.java:637)
at org.eclipse.birt.report.engine.data.dte.DteDataEngine.doExecuteQuery(DteDataEngine.java:152)
at org.eclipse.birt.report.engine.data.dte.AbstractDataEngine.execute(AbstractDataEngine.java:275)
at org.eclipse.birt.report.engine.executor.ExtendedGenerateExecutor.executeQueries(ExtendedGenerateExecutor.java:205)
at org.eclipse.birt.report.engine.executor.ExtendedGenerateExecutor.execute(ExtendedGenerateExecutor.java:65)
at org.eclipse.birt.report.engine.executor.ExtendedItemExecutor.execute(ExtendedItemExecutor.java:62)
at org.eclipse.birt.report.engine.internal.executor.dup.SuppressDuplicateItemExecutor.execute(SuppressDuplicateItemExecutor.java:43)
at org.eclipse.birt.report.engine.internal.executor.wrap.WrappedReportItemExecutor.execute(WrappedReportItemExecutor.java:46)
at org.eclipse.birt.report.engine.internal.executor.l18n.LocalizedReportItemExecutor.execute(LocalizedReportItemExecutor.java:34)
at org.eclipse.birt.report.engine.layout.html.HTMLBlockStackingLM.layoutNodes(HTMLBlockStackingLM.java:65)
at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layout(HTMLPageLM.java:92)
at org.eclipse.birt.report.engine.layout.html.HTMLReportLayoutEngine.layout(HTMLReportLayoutEngine.java:100)
at org.eclipse.birt.report.engine.api.impl.RunAndRenderTask.doRun(RunAndRenderTask.java:181)
at org.eclipse.birt.report.engine.api.impl.RunAndRenderTask.run(RunAndRenderTask.java:77)
at test.ReportTester.test(ReportTester.java:50)
at test.ReportTester.main(ReportTester.java:19)

Answer 1

除了捕获 BirtException 之外，您应该知道 BIRT 处理 Javascript 错误的方式(默认情况下)类似于浏览器。也就是说，BIRT 尝试继续生成报告。

对于生产质量代码(其中 task 是 RunAndRenderTask 或 RunTask 或 RenderTask)，有不同的方法来处理此问题:

• 使用 task.setErrorHandlingOption(CANCEL_ON_ERROR)(参见 BIRT docs)。就个人而言，我从未尝试过。

• 在 task.run(...) 之后，但在 task.close() 之前，调用 task.getErrors()。如果此列表不为空，您的代码应输出这些消息并抛出异常。