Merge pull request #12478 from thibaultfaure/articles/BAEL-5671-validate-an-xml-file-against-an-xsd

BAEL-5671 code for the validate an XML file against an XSD file article

xml-2/pom.xml

@@ -20,6 +20,12 @@
             <artifactId>dom4j</artifactId>
             <version>${dom4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>${junit-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

xml-2/src/main/java/com/baeldung/xml/validation/XmlErrorHandler.java

@@ -0,0 +1,35 @@
+package com.baeldung.xml.validation;
+
+import org.xml.sax.ErrorHandler;
+import org.xml.sax.SAXParseException;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class XmlErrorHandler implements ErrorHandler {
+
+    private List<SAXParseException> exceptions;
+
+    public XmlErrorHandler() {
+        this.exceptions = new ArrayList<>();
+    }
+
+    public List<SAXParseException> getExceptions() {
+        return exceptions;
+    }
+
+    @Override
+    public void warning(SAXParseException exception) {
+        exceptions.add(exception);
+    }
+
+    @Override
+    public void error(SAXParseException exception) {
+        exceptions.add(exception);
+    }
+
+    @Override
+    public void fatalError(SAXParseException exception) {
+        exceptions.add(exception);
+    }
+}

xml-2/src/main/java/com/baeldung/xml/validation/XmlValidator.java

@@ -0,0 +1,62 @@
+package com.baeldung.xml.validation;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.xml.sax.SAXException;
+import org.xml.sax.SAXParseException;
+
+import javax.xml.XMLConstants;
+import javax.xml.transform.Source;
+import javax.xml.transform.stream.StreamSource;
+import javax.xml.validation.Schema;
+import javax.xml.validation.SchemaFactory;
+import javax.xml.validation.Validator;
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+public class XmlValidator {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(XmlValidator.class);
+
+    private String xsdPath;
+    private String xmlPath;
+
+    public XmlValidator(String xsdPath, String xmlPath) {
+        this.xsdPath = xsdPath;
+        this.xmlPath = xmlPath;
+    }
+
+    public boolean isValid() throws IOException, SAXException {
+        Validator validator = initValidator(xsdPath);
+        try {
+            validator.validate(new StreamSource(getFile(xmlPath)));
+            return true;
+        } catch (SAXException e) {
+            return false;
+        }
+    }
+
+    public List<SAXParseException> listParsingExceptions() throws IOException, SAXException {
+        XmlErrorHandler xsdErrorHandler = new XmlErrorHandler();
+        Validator validator = initValidator(xsdPath);
+        validator.setErrorHandler(xsdErrorHandler);
+        try {
+            validator.validate(new StreamSource(getFile(xmlPath)));
+        } catch (SAXParseException e) {}
+        xsdErrorHandler.getExceptions().forEach(e -> LOGGER.info(e.getMessage()));
+        return xsdErrorHandler.getExceptions();
+    }
+
+    private Validator initValidator(String xsdPath) throws SAXException {
+        SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
+        Source schemaFile = new StreamSource(getFile(xsdPath));
+        Schema schema = factory.newSchema(schemaFile);
+        return schema.newValidator();
+    }
+
+    private File getFile(String location) {
+        return new File(getClass().getClassLoader().getResource(location).getFile());
+    }
+
+}

xml-2/src/main/resources/xml/validation/baeldung.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<individual>
+    <name>Baeldung</name>
+    <address>
+        <zip>00001</zip>
+        <city>New York</city>
+    </address>
+</individual>

xml-2/src/main/resources/xml/validation/full-person.xsd

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
+    <xs:element name="individual">
+        <xs:complexType>
+            <xs:sequence>
+                <xs:element name="name">
+                    <xs:simpleType>
+                        <xs:restriction base="xs:string">
+                            <xs:maxLength value="5" />
+                        </xs:restriction>
+                    </xs:simpleType>
+                </xs:element>
+                <xs:element name="address">
+                    <xs:complexType>
+                        <xs:sequence>
+                            <xs:element name="zip" type="xs:positiveInteger" />
+                            <xs:element name="city" type="xs:string" />
+                            <xs:element name="street" type="xs:string" />
+                        </xs:sequence>
+                    </xs:complexType>
+                </xs:element>
+            </xs:sequence>
+        </xs:complexType>
+    </xs:element>
+</xs:schema>

xml-2/src/main/resources/xml/validation/person.xsd

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
+    <xs:element name="individual">
+        <xs:complexType>
+            <xs:sequence>
+                <xs:element name="name" type="xs:string" />
+                <xs:element name="address">
+                    <xs:complexType>
+                        <xs:sequence>
+                            <xs:element name="zip" type="xs:positiveInteger" />
+                            <xs:element name="city" type="xs:string" />
+                        </xs:sequence>
+                    </xs:complexType>
+                </xs:element>
+            </xs:sequence>
+        </xs:complexType>
+    </xs:element>
+</xs:schema>

xml-2/src/test/java/com/baeldung/xml/validation/XmlValidatorUnitTest.java

@@ -0,0 +1,35 @@
+package com.baeldung.xml.validation;
+
+import org.junit.jupiter.api.Test;
+import org.xml.sax.SAXException;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class XmlValidatorUnitTest {
+
+    private static final String BAELDUNG_XML_PATH = "xml/validation/baeldung.xml";
+    private static final String PERSON_XSD_PATH = "xml/validation/person.xsd";
+    private static final String FULL_PERSON_XSD_PATH = "xml/validation/full-person.xsd";
+
+    @Test
+    public void givenValidXML_WhenIsValid_ThenTrue() throws IOException, SAXException {
+        assertTrue(new XmlValidator(PERSON_XSD_PATH, BAELDUNG_XML_PATH).isValid());
+    }
+
+    @Test
+    public void givenInvalidXML_WhenIsValid_ThenFalse() throws IOException, SAXException {
+        assertFalse(new XmlValidator(FULL_PERSON_XSD_PATH, BAELDUNG_XML_PATH).isValid());
+    }
+
+    @Test
+    public void givenValidXML_WhenListParsingExceptions_ThenNone() throws IOException, SAXException {
+        assertEquals(0, new XmlValidator(PERSON_XSD_PATH, BAELDUNG_XML_PATH).listParsingExceptions().size());
+    }
+
+    @Test
+    public void givenInvalidXML_WhenListParsingExceptions_ThenHasThree() throws IOException, SAXException {
+        assertEquals(3, new XmlValidator(FULL_PERSON_XSD_PATH, BAELDUNG_XML_PATH).listParsingExceptions().size());
+    }
+
+}