在Jaspersoft Studio 6.3中的TextField表达式中使用lambda表达式

编程入门行业动态更新时间:2024-10-12 05:51:52

本文介绍了在Jaspersoft Studio 6.3中的TextField表达式中使用lambda表达式的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！问题描述

我想在TextField表达式中使用lambda表达式，如下所示：

I want to use lambda expressions inside a TextField expression like this:

Arrays.asList($F{field1}, $F{field2}, $F{field3}).stream().filter(i -> i != null).collect(java.util.stream.Collectors.joining(" / "))

假设这些字段的值为：

$F{field1} = 1 $F{field2} = null $F{field3} = 2

TextField评估的预期结果是：

The expected result is of the TextField evaluation is:

1 / 2

而不是我在IDE中收到错误：

Instead of I'm getting an error in the IDE:

Lambda expressions are allowed only at source level 1.8 or above

这是编译期间IDE内的异常：

And this is the exception inside the IDE during the compile:

net.sf.jasperreports.engine.JRException: Errors were encountered when compiling report expressions class file: 1. Lambda expressions are allowed only at source level 1.8 or above value = "Contato: " + Arrays.asList(((java.lang.String)field_c_telefone.getValue()), ((java.lang.String)field_c_celular.getValue()), ((java.lang.String)field_c_fax.getValue()), ((java.lang.String)field_c_email.getValue())).stream().filter(i -> i != null).collect(java.util.stream.Collectors.joining(" / ")); //$JR_EXPR_ID=22$ <------------> 2. Lambda expressions are allowed only at source level 1.8 or above value = "Contato: " + Arrays.asList(((java.lang.String)field_c_telefone.getOldValue()), ((java.lang.String)field_c_celular.getOldValue()), ((java.lang.String)field_c_fax.getOldValue()), ((java.lang.String)field_c_email.getOldValue())).stream().filter(i -> i != null).collect(java.util.stream.Collectors.joining(" / ")); //$JR_EXPR_ID=22$ <------------> 3. Lambda expressions are allowed only at source level 1.8 or above value = "Contato: " + Arrays.asList(((java.lang.String)field_c_telefone.getValue()), ((java.lang.String)field_c_celular.getValue()), ((java.lang.String)field_c_fax.getValue()), ((java.lang.String)field_c_email.getValue())).stream().filter(i -> i != null).collect(java.util.stream.Collectors.joining(" / ")); //$JR_EXPR_ID=22$ <------------> 3 errors . at net.sf.jasperreports.engine.design.JRAbstractCompilerpileReport(JRAbstractCompiler.java:206) at net.sf.jasperreports.eclipse.builder.JasperReportCompilerpileReport(JasperReportCompiler.java:294) at net.sf.jasperreports.eclipse.builder.JasperReportCompilerpileReport(JasperReportCompiler.java:146) at net.sf.jasperreports.eclipse.builder.JasperReportsBuilderpileJRXML(JasperReportsBuilder.java:220) at com.jaspersoft.studio.editor.action.CompileAction.actionCompile(CompileAction.java:142) at com.jaspersoft.studio.editor.action.CompileAction$1.run(CompileAction.java:93) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

我已经将我的报告项目更改为使用JRE System 1.8，但错误仍在继续。

I already changed my report project to use the JRE System 1.8, but the error continues.

我该如何解决？ jasper编译器是否支持lambdas？

How can I solve it? Does jasper compiler supports lambdas?

推荐答案

要启用 Java 8 支持，请尝试将此3个参数添加到 Jaspersoft Studio.ini 文件（放置在 \ TIBCO \ Japersoft Studio-6.x.final 文件夹中）：

To enable Java 8 support try to add this 3 parameters to the Jaspersoft Studio.ini file (placed at \TIBCO\Jaspersoft Studio-6.x.final folder):

-Dorg.eclipse.jdt.corepiler.codegen.targetPlatform=1.8 -Dorg.eclipse.jdt.corepilerpliance=1.8 -Dorg.eclipse.jdt.corepiler.source=1.8

我的ini文件看起来像这样（对于 Jaspersoft Studio 6.3.1 版本）：

My ini file looks like this (for Jaspersoft Studio 6.3.1 version):

-startup plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar --launcher.library plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.300.v20150602-1417 -data @noDefault --launcher.defaultAction openFile -vm features/jre.win32.win32.x86_64.feature_1.8.0.u92/jre/bin -vmargs -Xms128m -Xmx1024m -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -Dfile.encoding=UTF-8 -Djava.preferIPv4Stack=true -Dorg.eclipse.jdt.corepiler.codegen.targetPlatform=1.8 -Dorg.eclipse.jdt.corepilerpliance=1.8 -Dorg.eclipse.jdt.corepiler.source=1.8

我检查了这份报告并且汇编并运作良好：

I checked this report and it compiled and worked well:

<?xml version="1.0" encoding="UTF-8"?> <jasperReport xmlns="jasperreports.sourceforge/jasperreports" xmlns:xsi="www.w3/2001/XMLSchema-instance" xsi:schemaLocation="jasperreports.sourceforge/jasperreports jasperreports.sourceforge/xsd/jasperreport.xsd" name="java8support" pageWidth="595" pageHeight="842" whenNoDataType="NoDataSection" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20"> <property name="com.jaspersoft.studio.data.defaultdataadapter" value="One Empty Record"/> <parameter name="p1" class="java.lang.String" isForPrompting="false"> <defaultValueExpression><![CDATA["1"]]></defaultValueExpression> </parameter> <parameter name="p2" class="java.lang.String" isForPrompting="false"> <defaultValueExpression><![CDATA["2"]]></defaultValueExpression> </parameter> <title> <band height="79" splitType="Stretch"> <textField> <reportElement x="80" y="20" width="234" height="30"/> <textFieldExpression><![CDATA[Arrays.asList($P{p1}, $P{p2}).stream().filter(i -> i != null).collect(java.util.stream.Collectors.joining(" / "))]]></textFieldExpression> </textField> </band> </title> </jasperReport>

编译结果：

JSS 中生成的结果：

我得到了同样的错误（ Lambda表达式仅允许在源级别1.8或以上），而不使用 JSS 中的这3个参数：

I got the same error (Lambda expressions are allowed only at source level 1.8 or above) without using this 3 parameters in JSS: