在JSF中处理BigDecimals

时间：2014-09-18 08:57:44

标签： jsf jsf-2.2 bigdecimal

我有以下BigDecimal转换器之一。

@ManagedBean
@ApplicationScoped
public final class BigDecimalGeneralConverter implements Converter {

    private static final int scale = IntegerConstants.MAX_FRACTIONAL_DIGITS.getValue();

    @Override
    public Object getAsObject(FacesContext context, UIComponent component, String value) {
        if (!StringUtils.isNotBlank(value)) {
            return null;
        }

        BigDecimal bigDecimal = null;
        try {
            bigDecimal = new BigDecimal(value);
            if (bigDecimal.scale() > scale) {
                bigDecimal = new BigDecimal(value).setScale(scale, RoundingMode.HALF_UP);
            }
        } catch (NumberFormatException e) {
            throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "", Utility.getMessage("bigdecimal.converter.error", 123.45)), e);
        }

        return bigDecimal.stripTrailingZeros();
    }

    @Override
    public String getAsString(FacesContext context, UIComponent component, Object value) {

        if (value == null) {
            return "";
        }

        if (!(value instanceof BigDecimal)) {
            //The exception occurs here.
            throw new ConverterException(Utility.getMessage("bigdecimal.converter.error", 123.45));
        }

        DecimalFormat formatter = (DecimalFormat) NumberFormat.getCurrencyInstance();
        DecimalFormatSymbols symbols = formatter.getDecimalFormatSymbols();
        symbols.setCurrencySymbol("");
        formatter.setGroupingUsed(false);
        formatter.setDecimalFormatSymbols(symbols);
        return formatter.format((BigDecimal) value);
    }
}

如下使用此转换器，

<h:outputText value="#{10.00}" converter="#{bigDecimalGeneralConverter}"/>

它会导致抛出以下异常。

SEVERE:   Error Rendering View[/admin_side/Test.xhtml]
javax.faces.convert.ConverterException: Failed to convert the value as a BigDecimal ex, 123.45.
    at converter.BigDecimalGeneralConverter.getAsString(BigDecimalGeneralConverter.java:58)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getFormattedValue(HtmlBasicRenderer.java:521)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getFormattedValue(HtmlBasicRenderer.java:540)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:357)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:164)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:70)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at filter.NoCacheFilter.doFilter(NoCacheFilter.java:28)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
    at java.lang.Thread.run(Thread.java:722)

INFO:   Exception when handling error trying to reset the response.
javax.faces.convert.ConverterException: Failed to convert the value as a BigDecimal ex, 123.45.
    at converter.BigDecimalGeneralConverter.getAsString(BigDecimalGeneralConverter.java:58)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getFormattedValue(HtmlBasicRenderer.java:521)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getFormattedValue(HtmlBasicRenderer.java:540)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:357)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:164)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:70)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at filter.NoCacheFilter.doFilter(NoCacheFilter.java:28)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
    at java.lang.Thread.run(Thread.java:722)

例如评论所指示的getAsString()方法中发生异常。该号码不会被识别为BigDecimal值。

仅当从关联的辅助bean /模型使用类型BigDecimal的属性时，此方法才有效。

<h:outputText value="#{order.discountAmount}"
              converter="#{bigDecimalGeneralConverter}"/>

我实际上需要设置如下条件。

<h:outputText value="#{not empty order.discountAmount ? order.discountAmount : 0}"
              converter="#{bigDecimalGeneralConverter}"/>

如果discountAmount实体中的Order属性为null，则会导致上述异常。

为什么它不能将文字值识别为BigDecimal值？

1 个答案:

答案 0 :(得分：2)

在EL中，#{42}等整数文字被解释为Long，而像#{12.34}这样的浮点文字被解释为Double。见a.o. EL 3.0 spec的第42页：

  
      
  • IntegerLiteral的值范围从Long.MIN_VALUE到Long.MAX_VALUE
    •   
  • FloatingPointLiteral的值范围从Double.MIN_VALUE到Double.MAX_VALUE
    •   

getAsString()中的传入值实际上是Double。只需相应调整代码; BigDecimal班级有constructor taking double。

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