Java – How to validate an XML against schema using JAXB

javajaxbunmarshallingxmlxsd

I am working with XML and JAXB as I am unmarshalling and marshalling the XML into Java objects and vice versa. Now I am trying to validate our XML against our schema(test.xsd). Suppose if any required field is missing in my XML, then I would like to know which field is missing after validating the XML against schema test.xsd.

public void unmarshal(final InputStream is) {
    final XMLInputFactory factory = XMLInputFactory.newInstance();
    final XMLStreamReader reader = factory.createXMLStreamReader(is);

    Object req = unmarshaller.unmarshal(reader);

    // how would I validate here?
}

How would I validate my XML against test.xsd schema. My test.xsd schema path is –

C:\workspace\one\two\three\src\main\java\com\package\serv\ap\versionOne\test.xsd

UPDATE: loading test.xsd as:

Schema schema = factorySchema.newSchema(new File("C:\\workspace\\one\\two\\three\\src\\main\\java\\com\\package\\serv\\ap\\versionOne\\test.xsd"));

Best Answer

You just need to set an instance of javax.xml.validation.Schema on the Unmarshaller before you do the unmarshal. You can specify an implementation of ValidationEventHandler on the Unmarshaller to catch any problems that occur during the unmarshal process.

http://docs.oracle.com/javase/7/docs/api/javax/xml/bind/Unmarshaller.html#setSchema%28javax.xml.validation.Schema%29

For More Information

I have written more about this use case on my blog:

http://blog.bdoughan.com/2010/12/jaxb-and-marshalunmarshal-schema.html

Related Solutions

Java – What’s the best way to validate an XML file against an XSD file

The Java runtime library supports validation. Last time I checked this was the Apache Xerces parser under the covers. You should probably use a javax.xml.validation.Validator.

import javax.xml.XMLConstants;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.*;
import java.net.URL;
import org.xml.sax.SAXException;
//import java.io.File; // if you use File
import java.io.IOException;
...
URL schemaFile = new URL("http://host:port/filename.xsd");
// webapp example xsd: 
// URL schemaFile = new URL("http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd");
// local file example:
// File schemaFile = new File("/location/to/localfile.xsd"); // etc.
Source xmlFile = new StreamSource(new File("web.xml"));
SchemaFactory schemaFactory = SchemaFactory
    .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
try {
  Schema schema = schemaFactory.newSchema(schemaFile);
  Validator validator = schema.newValidator();
  validator.validate(xmlFile);
  System.out.println(xmlFile.getSystemId() + " is valid");
} catch (SAXException e) {
  System.out.println(xmlFile.getSystemId() + " is NOT valid reason:" + e);
} catch (IOException e) {}

The schema factory constant is the string http://www.w3.org/2001/XMLSchema which defines XSDs. The above code validates a WAR deployment descriptor against the URL http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd but you could just as easily validate against a local file.

You should not use the DOMParser to validate a document (unless your goal is to create a document object model anyway). This will start creating DOM objects as it parses the document - wasteful if you aren't going to use them.

Java – How to create an executable JAR with dependencies using Maven

<build>
  <plugins>
    <plugin>
      <artifactId>maven-assembly-plugin</artifactId>
      <configuration>
        <archive>
          <manifest>
            <mainClass>fully.qualified.MainClass</mainClass>
          </manifest>
        </archive>
        <descriptorRefs>
          <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
      </configuration>
    </plugin>
  </plugins>
</build>

and you run it with

mvn clean compile assembly:single

Compile goal should be added before assembly:single or otherwise the code on your own project is not included.

See more details in comments.

Commonly this goal is tied to a build phase to execute automatically. This ensures the JAR is built when executing mvn install or performing a deployment/release.

<plugin>
  <artifactId>maven-assembly-plugin</artifactId>
  <configuration>
    <archive>
      <manifest>
        <mainClass>fully.qualified.MainClass</mainClass>
      </manifest>
    </archive>
    <descriptorRefs>
      <descriptorRef>jar-with-dependencies</descriptorRef>
    </descriptorRefs>
  </configuration>
  <executions>
    <execution>
      <id>make-assembly</id> <!-- this is used for inheritance merges -->
      <phase>package</phase> <!-- bind to the packaging phase -->
      <goals>
        <goal>single</goal>
      </goals>
    </execution>
  </executions>
</plugin>

Best Answer

Related Solutions

Java – What’s the best way to validate an XML file against an XSD file

Java – How to create an executable JAR with dependencies using Maven

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