docs(xsd-java): run XsdValidate.java directly via JDK source launcher (no Maven needed)

README.md

@@ -134,7 +134,7 @@ XSD=https://github.com/fundsxml/schema/releases/download/4.2.9/FundsXML.xsd
 # XSD validation — pick any stack (schema + xml, schema-first):
 python XSD_Validation/python/validate.py "$XSD" $SRC
 dotnet run --project XSD_Validation/dotnet -- "$XSD" $SRC
-./mvnw -q -pl XSD_Validation/java compile exec:java -Dexec.args="$XSD $SRC"
+java XSD_Validation/java/XsdValidate.java "$XSD" $SRC   # JDK 11+ only, no Maven needed
 XSD_Validation/cli/validate.sh "$XSD" $SRC          # Windows: pwsh .../validate.ps1
 
 # Schematron business rules (SVRL; exit 0 = no ERROR-role failures)

XSD_Validation/README.md

@@ -78,7 +78,17 @@ python XSD_Validation/python/validate.py "$REL" FundsXML_Files/4.2.9/positions/M
 python XSD_Validation/python/validate.py "$REL" tests/fixtures/invalid/xsd-invalid_Positions.xml         # exit 1
 ```
 
-Java (standalone): `./mvnw -q -pl XSD_Validation/java compile exec:java -Dexec.args="$REL <file>"`
+Java (standalone, JDK 11+ only — no Maven needed, the example has no
+dependencies beyond the JDK):
+
+```bash
+java XSD_Validation/java/XsdValidate.java "$REL" FundsXML_Files/4.2.9/positions/Mixed-Fund_Positions.xml  # exit 0
+java XSD_Validation/java/XsdValidate.java "$REL" tests/fixtures/invalid/xsd-invalid_Positions.xml         # exit 1
+```
+
+(Windows: `java XSD_Validation\java\XsdValidate.java <schema> <xml-file>`.)
+The same class also runs through the Maven aggregator, which is what CI uses:
+`./mvnw -q -pl XSD_Validation/java compile exec:java -Dexec.args="$REL <file>"`
 (`mvnw.cmd` on Windows).
 
 .NET (standalone): `dotnet run --project XSD_Validation/dotnet -- "$REL" <file>`

XSD_Validation/java/XsdValidate.java

@@ -1,10 +1,19 @@
 // XSD validation in native Java (no JAXB) via javax.xml.validation.
 //
 // Standalone & cross-platform — no prior tool, no bash, works on Windows.
-// Run from the repo root with the committed Maven Wrapper:
+// The only dependency is the JDK itself (javax.xml.validation + java.net.http),
+// so no build tool is needed: JDK 11+ compiles and runs a single source file
+// directly (JEP 330). Run from the repo root:
+//   java XSD_Validation/java/XsdValidate.java \
+//       https://github.com/fundsxml/schema/releases/download/4.2.9/FundsXML.xsd \
+//       FundsXML_Files/4.2.9/positions/Mixed-Fund_Positions.xml
+// (Windows: java XSD_Validation\java\XsdValidate.java <schema> <xml-file>)
+//
+// Alternatively via the committed Maven Wrapper (the module is part of the
+// root aggregator so `./mvnw compile` builds it together with the other
+// examples; it has no dependencies of its own):
 //   ./mvnw -q -pl XSD_Validation/java compile exec:java \
-//       -Dexec.args="https://github.com/fundsxml/schema/releases/download/4.2.9/FundsXML.xsd \
-//                     FundsXML_Files/4.2.9/positions/Mixed-Fund_Positions.xml"
+//       -Dexec.args="<schema> <xml-file>"
 // Exit: 0 = valid, 1 = invalid, 2 = usage/setup error
 //
 // You give it exactly two things: the schema and the instance. <schema> is a
@@ -79,13 +88,26 @@ public static void main(String[] args) throws Exception {
             factory.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "file");
             factory.setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, "");
 
-            Schema fundsXmlSchema = factory.newSchema(schemaFile);
+            // A missing, unreadable or malformed *schema* is a setup error
+            // (exit 2), not an invalid instance (exit 1) — report it in one
+            // line instead of letting the SAXParseException stack-trace out.
+            Schema fundsXmlSchema;
+            try {
+                fundsXmlSchema = factory.newSchema(schemaFile);
+            } catch (SAXParseException e) {
+                System.err.println("cannot load schema " + schemaArg + ": "
+                                   + e.getMessage());
+                System.exit(2);
+                return;
+            }
             Validator validator = fundsXmlSchema.newValidator();
             validator.setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, "");
             validator.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "file");
 
             final boolean[] failed = {false};
             validator.setErrorHandler(new ErrorHandler() {
+                // Schema warnings (e.g. unused imports) never affect
+                // validity — deliberately ignored to keep the output clean.
                 public void warning(SAXParseException e) { }
                 public void error(SAXParseException e) { report(e); }
                 public void fatalError(SAXParseException e) { report(e); }

XSD_Validation/java/pom.xml

@@ -1,12 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
   XSD validation in native Java (javax.xml.validation, no JAXB). No third-party
-  dependencies — the JDK is the whole runtime. The schema is obtained by the
-  example itself (env var / local cache / official download), see XsdValidate.java.
+  dependencies at all: the JDK is the whole runtime. Because of that, Maven is
+  NOT required to run this example. The JDK's source launcher (JDK 11+) does it
+  in one call from the repo root:
+    java XSD_Validation/java/XsdValidate.java <schema> <xml-file>
+  where <schema> is a local FundsXML.xsd path or a remote URL, see
+  XsdValidate.java.
 
-  Run from the repo root:
+  This module exists only so the root aggregator (./mvnw compile, CI) builds
+  every Java example uniformly. The equivalent Maven invocation is:
     ./mvnw -q -pl XSD_Validation/java compile exec:java \
-        -Dexec.args="4.2.9 FundsXML_Files/4.2.9/positions/Mixed-Fund_Positions.xml"
+        -Dexec.args="<schema> <xml-file>"
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"