JasperReports 中当其值为 NULL 或空时隐藏图像

Question

我使用的是 JasperReports 6.2.2 版本。如果值为 null 或空，我想隐藏图像。

下面的代码我在 jrxml 中使用来隐藏图像，但这对我不起作用。

<image>
    <reportElement x="33" y="0" width="88" height="45" uuid="182b40f8-b18e-417c-b9f4-096199533567">
        <printWhenExpression><![CDATA[($F{urlImage}!=null ? $F{urlImage} : "")]]></printWhenExpression>
    </reportElement>
</image>

$F{urlImage} 是 String 类型

它给出了一个错误

ERROR [btpool0-2] (JRFillSubreport.java:866) - Fill 1: exception
     [java] java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Boolean
     [java]     at net.sf.jasperreports.engine.fill.JRFillElement.evaluatePrintWhenExpression(JRFillElement.java:806)
     [java]     at net.sf.jasperreports.engine.fill.JRFillImage.evaluate(JRFillImage.java:471)
     [java]     at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:381)
     [java]     at net.sf.jasperreports.engine.fill.JRFillFrame.evaluate(JRFillFrame.java:159)
     [java]     at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:381)
     [java]     at net.sf.jasperreports.engine.fill.JRFillBand.evaluate(JRFillBand.java:500)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:2022)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:748)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:255)
     [java] java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Boolean
     [java]     at net.sf.jasperreports.engine.fill.JRFillElement.evaluatePrintWhenExpression(JRFillElement.java:806)
     [java]     at net.sf.jasperreports.engine.fill.JRFillImage.evaluate(JRFillImage.java:471)
     [java]     at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:381)
     [java]     at net.sf.jasperreports.engine.fill.JRFillFrame.evaluate(JRFillFrame.java:159)
     [java]     at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:381)
     [java]     at net.sf.jasperreports.engine.fill.JRFillBand.evaluate(JRFillBand.java:500)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:2022)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:748)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:255)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:115)
     [java]     at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:580)
     [java]     at net.sf.jasperreports.engine.fill.BaseReportFiller.fill(BaseReportFiller.java:414)
     [java]     at net.sf.jasperreports.engine.fill.JRFillSubreport.fillSubreport(JRFillSubreport.java:736)
     [java]     at net.sf.jasperreports.engine.fill.JRSubreportRunnable.run(JRSubreportRunnable.java:59)
     [java]     at net.sf.jasperreports.engine.fill.AbstractThreadSubreportRunner.run(AbstractThreadSubreportRunner.java:221)
     [java]     at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
     [java]     at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
     [java]     at java.lang.Thread.run(Unknown Source)
     [java]     at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:115)
     [java]     at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:580)
     [java]     at net.sf.jasperreports.engine.fill.BaseReportFiller.fill(BaseReportFiller.java:414)
     [java]     at net.sf.jasperreports.engine.fill.JRFillSubreport.fillSubreport(JRFillSubreport.java:736)
     [java]     at net.sf.jasperreports.engine.fill.JRSubreportRunnable.run(JRSubreportRunnable.java:59)
     [java]     at net.sf.jasperreports.engine.fill.AbstractThreadSubreportRunner.run(AbstractThreadSubreportRunner.java:221)
     [java]     at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
     [java]     at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
     [java]     at java.lang.Thread.run(Unknown Source)

如果图像的值为 null 或空，如何隐藏图像。urlImage 字段包含图像的 url。例如：“[ http://use.example.com/pop.png][1] ”。

Answer 1

您可以在 Jaspersoft Studio 中执行此操作：

这会在 jrxml 中创建以下行：

<image isUsingCache="true" onErrorType="Blank">