Use map function to change field value using xslt 3.0 - xslt

Question

I need to map field value from hash table only in Debtor field and other values remains same.
I want the all other fields to be as it is and only change the map the debtor fields.
P_BPMapping - {"BANK1":"1","BANK2":"2","BANK3":"3","BANK4":"4"}
My input xml
<?xml version="1.0" encoding="UTF-8"?>
<JECreateRequest>
<MessageHeader>
</MessageHeader>
<JournalEntryCreateRequest>
<MessageHeader>
<JournalEntry>
<DebtorItem>
<Debtor>BANK1</Debtor>
</DebtorItem>
</JournalEntry>
</MessageHeader>
</JournalEntryCreateRequest>
<JournalEntryCreateRequest>
<MessageHeader>
<JournalEntry>
<DebtorItem>
<Debtor>BANK2</Debtor>
</DebtorItem>
<DebtorItem>
<Debtor>BANK1</Debtor>
</DebtorItem>
</JournalEntry>
</MessageHeader>
</JournalEntryCreateRequest>
<JournalEntryCreateRequest>
<MessageHeader>
<JournalEntry>
<DebtorItem>
<Debtor>BANK4</Debtor>
</DebtorItem>
<DebtorItem>
<Debtor>BANK3</Debtor>
</DebtorItem>
<DebtorItem>
<Debtor>BANK1</Debtor>
</DebtorItem>
</JournalEntry>
</MessageHeader>
</JournalEntryCreateRequest>
</JournalEntryBulkCreateRequest>
Hash Table
BANK1 - 1
BANK2 - 2
BANK3 - 3
BANK4 - 4
My XSLT code - I have tried with this XSLT code and getting error.
<xsl:stylesheet
version="3.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:map="http://www.w3.org/2005/xpath-functions/map"
<xsl:output method="xml" encoding="UTF-8" indent="yes"/>
<xsl:strip-space elements="*"/>
<!-- Start of enhancement - ValueMapping for Payloution Customer -->
<xsl:param name="P_BPMapping" />
<xsl:param name="MapDebitor" as="map(*)" select="parse-json($P_BPMapping)" />
<!-- End of enhancement -->
<!-- identity transform -->
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<!--
<xsl:for-each select ="MessageHeader/JournalEntryCreateRequest/JournalEntry/DebtorItem">
-->
<xsl:template match="MessageHeader">
<xsl:for-each select ="JournalEntryCreateRequest/JournalEntry/DebtorItem">
<xsl:template match="Debtor">
<xsl:copy>
<xsl:choose>
<xsl:when test="map:get($MapDebitor,Debtor)">
<xsl:value-of select="map:get($MapDebitor,Debtor)" />
</xsl:when>
<xsl:otherwise>
<error>
<xsl:text>Error in BusinessPartner mapping. Please maintain the mapping for the following debtor: </xsl:text>
<xsl:value-of select="Debtor"/>
</error>
</xsl:otherwise>
</xsl:choose>
</xsl:copy>
</xsl:template>
</xsl:for-each>
</xsl:template>
<!--
</xsl:for-each>
-->
</xsl:stylesheet>
Expected output
<?xml version="1.0" encoding="UTF-8"?>
<JECreateRequest>
<MessageHeader>
</MessageHeader>
<JournalEntryCreateRequest>
<MessageHeader>
<JournalEntry>
<DebtorItem>
<Debtor>1</Debtor>
</DebtorItem>
</JournalEntry>
</MessageHeader>
</JournalEntryCreateRequest>
<JournalEntryCreateRequest>
<MessageHeader>
<JournalEntry>
<DebtorItem>
<Debtor>2</Debtor>
</DebtorItem>
<DebtorItem>
<Debtor>1</Debtor>
</DebtorItem>
</JournalEntry>
</MessageHeader>
</JournalEntryCreateRequest>
<JournalEntryCreateRequest>
<MessageHeader>
<JournalEntry>
<DebtorItem>
<Debtor>4</Debtor>
</DebtorItem>
<DebtorItem>
<Debtor>3</Debtor>
</DebtorItem>
<DebtorItem>
<Debtor>1</Debtor>
</DebtorItem>
</JournalEntry>
</MessageHeader>
</JournalEntryCreateRequest>
</JournalEntryBulkCreateRequest>

Answer 1

I would use e.g.
<xsl:param name="map-data" as="xs:string" expand-text="no">{"BANK1":"1","BANK2":"2","BANK3":"3","BANK4":"4"}</xsl:param>
<xsl:param name="map" select="parse-json($map-data)"/>
<xsl:template match="Debtor[map:contains($map, .)]">
<xsl:copy>{$map(.)}</xsl:copy>
</xsl:template>
<xsl:mode on-no-match="shallow-copy"/>
(with xmlns:map="http://www.w3.org/2005/xpath-functions/map" and expand-text="yes" being declared in the XSLT).
Your code also seems to try to find non-matching Debtors and output some error so perhaps an additional template
<xsl:template match="Debtor[not(map:contains($map, .))]">
<xsl:copy>
<error>Error in BusinessPartner mapping. Please maintain the mapping for the following debtor: {.}</error>
</xsl:copy>
</xsl:template>
is needed, though the input/output samples don't show that case.
Online sample demo.