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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(" / "))
Assuming this values for the fields:
$F{field1} = 1
$F{field2} = null
$F{field3} = 2
The expected result is of the TextField evaluation is:
1 / 2
Instead of I'm getting an error in the IDE:
Lambda expressions are allowed only at source level 1.8 or above
And this is the exception inside the IDE during the compile:
net.sf.jasperreports.engine.JRException: Errors were encountered when compiling report expressions class file:
1. Lambda expressions are allowed only at source level 1.8 or above
value = "Contato: " + Arrays.asList(((java.lang.String)field_c_telefone.getValue()), ((java.lang.String)field_c_celular.getValue()), ((java.lang.String)field_c_fax.getValue()), ((java.lang.String)field_c_email.getValue())).stream().filter(i -> i != null).collect(java.util.stream.Collectors.joining(" / ")); //$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.JRAbstractCompiler.compileReport(JRAbstractCompiler.java:206)
at net.sf.jasperreports.eclipse.builder.JasperReportCompiler.compileReport(JasperReportCompiler.java:294)
at net.sf.jasperreports.eclipse.builder.JasperReportCompiler.compileReport(JasperReportCompiler.java:146)
at net.sf.jasperreports.eclipse.builder.JasperReportsBuilder.compileJRXML(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)
I already changed my report project to use the JRE System 1.8, but the error continues.
How can I solve it? Does jasper compiler supports lambdas?
431
JasperReports doesn't support if-else statements when defining variable expressions. Instead, you can use the ternary operators {cond} ? {statement 1} : {statement 2}. This operator can be nested inside a Java expression to obtain the desired output based on multiple conditions.
As with many other elements, all the defined variables are visible in the Outline menu under the item called "Variables". From there you can create a new variable (right click on the "Variables" item and then "Create variable") and, once selected, a variable its properties are visible on the Properties tab.
jasper. properties is looked up by jasper reports in the classpath, so it can be directly in the WEB-INF/classes folder, or in the root folder of any of the jars in WEB-INF/lib.
To create a field, right-click the Fields node and select Create Field. The new field is included as an undefined entry on the Properties tab. You can configure the field properties by selecting it.
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.core.compiler.codegen.targetPlatform=1.8
-Dorg.eclipse.jdt.core.compiler.compliance=1.8
-Dorg.eclipse.jdt.core.compiler.source=1.8
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.net.preferIPv4Stack=true
-Dorg.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
-Dorg.eclipse.jdt.core.compiler.compliance=1.8
-Dorg.eclipse.jdt.core.compiler.source=1.8
I checked this report and it compiled and worked well:
<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/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>
Compiling result:
The generated result in JSS:
I got the same error (Lambda expressions are allowed only at source level 1.8 or above) without using this 3 parameters in JSS:
94
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