Java servlets: xml validation against xsd-Collection of common programming errors

I have servlet which uses utility packaged in .jar archive:

@Override
public void init() throws ServletException {
    ...
    try (InputStream stream = getClass().getResourceAsStream("/fileToParse.xml")) {
        App.check(stream);
    } catch (Exception e) {
        throw new ServletException(e);
    }
    ...
}

This utility takes xml file stream, performs validation against xsd schema and parses it:

public class App {
    private static final String JAXP_SCHEMA_LANGUAGE = "http://java.sun.com/xml/jaxp/properties/schemaLanguage";
    private static final String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema"; 
    ...   
    public static void check(InputStream stream) {    
        SAXParserFactory spf = SAXParserFactory.newInstance();
        spf.setNamespaceAware(true);
        spf.setValidating(true);
        MyHandler handler = new MyHandler();
        try {
            SAXParser sp = spf.newSAXParser();
            sp.setProperty(JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA);
            XMLReader rdr = sp.getXMLReader();
            rdr.setContentHandler(handler);
            rdr.setErrorHandler(new MyErrorHandler());
            rdr.parse(new InputSource(stream));
        }
        ...
    }
    ...
}

xsd file starts with:

    
        ...

xml file:

    ...

.war structure:

css/
js/
WEB-INF/
    classes/
        mypackage/
            MyServlet.class
        fileToParse.xml
    lib/
        App.jar
    web.xml

App.jar structure:

mypackage2/
    App.class
appContext.xsd

Servlet Init method throws exception:

...
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_21]
    at java.lang.Thread.run(Thread.java:722) [na:1.7.0_21]
Caused by: java.io.FileNotFoundException: /PATH_TO_TOMCAT/bin/appContext.xsd (No such file or directory)
    at java.io.FileInputStream.open(Native Method) ~[na:1.7.0_21]
    at java.io.FileInputStream.(FileInputStream.java:138) ~[na:1.7.0_21]

How I can specify to SAXParser where is xsd schema needed to validate xml file?

P.S. Sorry for my bad English

UPD:

I’m trying to add this property:

    private static final String JAXP_SCHEMA_SOURCE =
            "http://java.sun.com/xml/jaxp/properties/schemaSource";
    ....
    public static void check(InputStream stream) {
        ...
        try {
            ...
            sp.setProperty(JAXP_SCHEMA_SOURCE, new File(getPath("/appContext.xsd")));
            ...
        }
    }
    public static String getPath(String path) {
        return App.class.getResource(path).toString();
    }

Now I have this exception:

ERROR mypackage2.App - Error: URI=null Line=5: schema_reference.4: Failed to read schema document 'jar:file:/PATH_TO_TOMCAT/webapps/myapp/WEB-INF/lib/App.jar!/appContext.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not .
org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'jar:file:/PATH_TO_TOMCAT/webapps/myapp/WEB-INF/lib/App.jar!/appContext.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not .
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:198) ~[na:1.7.0_21]

UPD2: With “classpath:appContext.xsd” in xml file:

WARN  mypackage.App - Warning: URI=null Line=5: schema_reference.4: Failed to read schema document 'classpath:appContext.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not .
org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'classpath:appContext.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not .
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:198) ~[na:1.7.0_21]
...
    at java.lang.Thread.run(Thread.java:722) [na:1.7.0_21]
Caused by: java.net.MalformedURLException: unknown protocol: classpath
    at java.net.URL.(URL.java:592) ~[na:1.7.0_21
;;;