[How to fix Unknown Source error?]

Step by step.

Try delete subreport 2 from main report and run main report again. Will the error appear again in this case?

It is very strangely use $F{fieldName} at band Last Page Footer. It seems all fields equals null in this band. So expression $F{SHeft}.equals(Boolean.TRUE.toString()) can generate NPE.
Use "Yoda condition" to avoid such NPE. For instance change expression to (Boolean.TRUE.toString()).equals( $F{SHeft})

HTH

 

[How to export excel data in jasper report using java]

https://stackoverflow.com/a/10918731/2042583

[Sub Reports with XML data]

Don't use absolute path starting from /main-report
Use relative path
https://community.jaspersoft.com/questions/524978/empty-subreport-xml-datasource-ireport

[How to display text field grow to untill the next record.]

See attributes of textfield $F{name} in country.jrxml
reportElement stretchType="RelativeToBandHeight" and
textElement textAlignment="Center" verticalAlignment="Middle"
 

[How to display text field grow to untill the next record.]

https://stackoverflow.com/questions/34171805/how-to-merge-cells-in-same-column-apply-rowspan

[passing filed value from master to subreport]

>>1. Create a parameter "HawbNumber" in master 
It is not need create useless parameter in main report

5. Added  parameter expression   $P{HawbNumber}

Why? You want pass field not parameter main report.
Change expression like $F{myField} -  field of main report

[passing filed value from master to subreport]

>>without the field that i passed to subreport

You pass parameter of main report to subreport.
You don't pass field.

Question unclear

[Using substring to convert number to text.]

Duggu09's answer is great.
A small correction:
Use
Ex: "1".equals($F{FieldName}) ? "INV" : $F{FieldName} 

to avoid a potentional NullPointerException

[Subreport data in Java]

Usially subreport expression like this:

$P(SUBREPORT_DIR)+"mySubreportName.jasper" 

You pass $P{subreportParameter}  from main report as parameter of subreport (which? it seems it not defined yet). It is very unclear (imho).
And what the reason use dynamic subreport name?
For exaple myFirstReport.jrxml include executing subreport1.jassper
and mySecondReport.jrxml include executing subreport2 and may be subreport3.jasper

I can't see the reason use dynamic executing subreport1 in mySecondReport.jrxml

Sorry for chaotic answer... but question is chaotic too )))

Try use static subreport name in mainReport.jrxml

One useful link:
https://stackoverflow.com/questions/18656016/jasperreports-cant-locate-subreport
 

[why right alignment is not working on text field]

In my reports alignment works well
Try to ask correct question

From SO:
"Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers

[Subreport should get all values]

1. Are you sure that $F{cnt_benennung}.intValue()   count a "zeile" but not "benennung" ?
2. Positions for Row 2 and Row 4  equals 2 but not 4  imho
3. It is not clear for me how you can "find"  Row 1 and Row 2  with condition   =  zeile[position>4]

Question unclear.

[Complex SQL to Jaspersoft statement help]

@jack_w

What is the point use 2 subqueries with condition WHERE "Id" = Z."PytanieId"  instead one query with left join without subqueries?

[JasperSoft iReport]

Show picture. Question is unclear

[How delete backcolor property from JasperStudio interface?]

It’s too funny for words. It real works! Thanx

[How delete backcolor property from JasperStudio interface?]

Hi, All

Conditional style don't work when report element contain backcolor attribute.
Little duscussion here https://community.jaspersoft.com/questions/1042866/background-color-conditional-style-doesnt-drawn

I can't find method delete backcolor attribute in report element from JasperStudio 6.4.0 using only UI
When I delete it from bookmark "Source" then Studio can't show report in Design mode.
After closing and reopening report Studio work fine.
I have many fields in report so it is not so pleasure to close and reopen report after any changes.

How I can delete backcolor from Studio UI ?

Part of jrxml

    <style name="temperatureInput" pattern="###0.00" fontSize="12">
        <box>
            <pen lineWidth="0.5"/>
            <topPen lineWidth="0.5"/>
            <leftPen lineWidth="0.5"/>
            <bottomPen lineWidth="0.5"/>
            <rightPen lineWidth="0.5"/>
        </box>
        <conditionalStyle>
            <conditionExpression><![CDATA[$F{temperature_input}.getHole() == 0]]></conditionExpression>
            <style mode="Transparent" forecolor="#000000" isBlankWhenNull="false"/>
        </conditionalStyle>
        <conditionalStyle>
            <conditionExpression><![CDATA[$F{temperature_input}.getHole() != 0]]></conditionExpression>
            <style mode="Opaque" forecolor="#000000" backcolor="#FFFF00" isBlankWhenNull="false"/>
        </conditionalStyle>
    </style>
...

                            <jr:detailCell height="20">
                                <textField pattern="" isBlankWhenNull="true">
                                    <reportElement style="temperatureInput" mode="Opaque" x="0" y="0" width="60" height="20" backcolor="#FFFFFF" uuid="ee2ee2fe-032c-4b60-8fc1-807e9a9500e7"/>
                                    <box>
                                        <pen lineWidth="0.5"/>
                                        <topPen lineWidth="0.5"/>
                                        <leftPen lineWidth="0.5"/>
                                        <bottomPen lineWidth="0.5"/>
                                        <rightPen lineWidth="0.5"/>
                                    </box>
                                    <textElement textAlignment="Right" verticalAlignment="Middle" markup="none">
                                        <font fontName="DejaVu Sans" size="12"/>
                                    </textElement>
                                    <textFieldExpression><![CDATA[$F{temperature_input}.getValue()]]></textFieldExpression>
                                </textField>
                            </jr:detailCell>

 

[Print Table Lost First Item Data]

https://stackoverflow.com/questions/18787697/table-tool-in-showing-one-fewer-lesser-database-records

[Hide a group Row in a Table element]

There is no way yet AFAIK. For instance link on analogical question
https://community.jaspersoft.com/questions/542144/ireport-412-can-i-hide-table-footer-table-component-using-something
 

[How get fields of object in parameter iReport]

https://stackoverflow.com/questions/17140903/field-inside-field-on-jasperreports

Use $P{myParam}.getMyField() in expressions (or text fields)

[Same day different hours, no result in query]

>> I found a solution for this. If the Input Parameter is java.util.Date type the hours are not taken into consideration in query
>> I changed the Input Parameter type to java.sql.Timestamp and now hours are taken into consideration.
It is not solution. You have to check your java code
I make test report and it work fine with java.util.Date. My test report shows parameters in title of report with hours !=0. And it uses hours in query correctly

You have a chance get unexpected errors because your solution hide potentional errors (types casting?, parsing?, ...?)
I hope you will find a time to solve this problem in right way.
Good luck

[Same day different hours, no result in query]

Probably you executed unnecessary processing of parameters.
I don't undersatnd 2 point:

1. The input controls were formated to java.util.Date format (3th message)
2. Using methos parseParameter  ( https://ibb.co/gZMLt6 ) ?

[Same day different hours, no result in query]

Java code looks correct. I cant't see value $P{DateFromInputControl}

may by your code like this?
fillParams.put("DateFromInputControl", dateFrom);
fillParams.put("DateToInputControl", dateFrom);

Show declaration ( and new () ) for map fillParams and how you put values into this map in java code.
Why parameter names starting from upper letter?

[Same day different hours, no result in query]

You should post minimal example (calling report from java with passing parameters)
And show part of jrxml with definition parameters and query

[Subreports: error preparing statement for executing the report query]

You can't get right answer with uncorrect question.

<![CDATA[select pofr.id
        from
        where pofr.id = $P{POFR_ID}]]>

Where tableName after from? This select can not work.

And you wrote: the subreport runs perfectly fine on its own

[Problem with parameter passing to queryString]

src? Really?
How RunReport.class not RunReport.java (your ".java code") can compile jrxml at "src/main/resources/tempSKDFiltered.jrxml" ?

[Could you explain me XML Data Source and Subreports example?]

1. Change structure node email xml like node hobbies

2. Use query // (not /) for subreport, for instance ((net.sf.jasperreports.engine.data.JRXmlDataSource) $P{REPORT_DATA_SOURCE}).subDataSource("//hobbies")