Validation of XML files in Java

Use DTD to validate XML files in Java:

1. Define a Check class Checkxml class:

Import org.w3c.dom.Document;

Import Org.xml.sax.EntityResolver;
Import Org.xml.sax.ErrorHandler;
Import Org.xml.sax.InputSource;
Import org.xml.sax.SAXException;
Import org.xml.sax.SAXParseException;

Import java.io.IOException;
Import Java.io.InputStream;
Import Java.net.URL;

Import Javax.xml.parsers.DocumentBuilder;
Import Javax.xml.parsers.DocumentBuilderFactory;
Import javax.xml.parsers.ParserConfigurationException;

public class Checkxml () {

Public Doucment Getcheckxml () {

list<studentuao> result = new arraylist<> ();

Use the Java ClassLoader to find the resource file under the classpath.

1. Gets the object of any class type, the class name. Classes can return a class object.

class<?> clazz = Teststudent.class;

2. Call getResourceAsStream (arg0) to get the input stream.

Look for a file named Book.xml from the root of the classpath.

Automatically finds a file named Student.xml under all Classpath, returns immediately after finding the first one, and does not continue looking.

URL url = Clazz.getresource ("./student.xml");

The following is the root directory of the output Student.xml file

System.out.println (URL);

InputStream in = Url.openstream ();

1. Create Documentbuilderfactory

Documentbuilderfactory builderfactory = Documentbuilderfactory.newinstance ();

Turn on validation!

Builderfactory.setvalidating (TRUE);

2. Create Documentbuilder with Documentbuilderfactory

Documentbuilder builder = Builderfactory.newdocumentbuilder ();

3. Use Entityresolver to tell the XML parser where the DTD file is!

Also under the classpath of the current class, look for the Student.dtd file

Builder.setentityresolver (New Entityresolver () {

@Override

Public InputSource resolveentity (string arg0, String arg1) throws Saxexception, IOException {

InputStream Dtdstream = Clazz.getresourceasstream ("./student.dtd");

InputSource Source = new InputSource (dtdstream);

return source;

}

});

4. In order to be able to obtain the accurate analysis verification information, must provide a ErrorHandler

MyErrorHandler eh = new MyErrorHandler ();

Builder.seterrorhandler (EH);

if (Eh.issucceed ()) {

System.out.println ("Parse success! ");

5. Execution resolution

The bottom layer reads the XML content using sax, so the read performance is better

Document doc = Builder.parse (in);

return doc;

}else{

System.out.println ("Parse failed! ");

return null;

}

}

Static Class MyErrorHandler implements ErrorHandler {

Private Integer errorcount = 0;

@Override

public void error (Saxparseexception arg0) throws Saxexception {

System.out.println ("There is an error! ");

Arg0.printstacktrace (System.out);

errorcount++; }

@Override

public void FatalError (Saxparseexception arg0) throws Saxexception {

SYSTEM.OUT.PRINTLN ("A fatal error has occurred! ");

Arg0.printstacktrace (System.out);

errorcount++; }

@Override

public void Warning (saxparseexception arg0) throws Saxexception {

System.out.println ("Warning appears! ");

Arg0.printstacktrace (System.out); }

Determine if the resolution is successful!

public Boolean issucceed () {if (Errorcount = = 0) {return true;   } return false; }  }

}

1.2DOM4J using DTD checksum xml:

1. Create Saxreader Saxreader reader = new Saxreader ();

2. Turn on Verify reader.setvalidation (true);

3. Set Entityresolver, in dom4j, the default to find the same directory of the DTD file/

/Provide the reason for the setentityresolver, mainly to solve: if the XML declaration of the DTD file and the actual DTD file name is different, can correctly find the DTD

Reader.setentityresolver (New Entityresolver () {

@Override

Public InputSource resolveentity (string publicid, String systemid) throws Saxexception, IOException {

URL Dtdurl = Cla.getresource ("./students.dtd");

InputStream Dtdstream = Dtdurl.openstream ();

InputSource Source = new InputSource (dtdstream);

return source; }   });

4. Read the XML to generate the Document object
Document document = Reader.read (URL);

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Java uses schame to validate XML files:

2.1 Create a VALIDATIONXM class:

Import java.io.IOException;

Import Java.io.InputStream;

Import Java.net.URL;

Import javax.xml.XMLConstants;

Import Javax.xml.transform.stream.StreamSource;

Import Javax.xml.validation.Schema; Import Javax.xml.validation.SchemaFactory;

Import Javax.xml.validation.Validator;

Import org.xml.sax.SAXException;

public class Validationxml {

public static void Getvalidationxml () throws Saxexception, IOException {

URL url = ValidationXML.class.getResource ("book.xsd");

Reading the schema file

Schema s = schemafactory.newinstance (Xmlconstants.w3c_xml_schema_ns_uri). Newschema (URL);

Creating validators

Validator v = s.newvalidator ();

Validating an input stream

InputStream in = ValidationXML.class.getResourceAsStream ("/book.xml");

Streamsource Source = new Streamsource (in);

V.validate (source);

Verify no error to read

...--------------();

} }

3. Use dom4j: Two packages required: Dom4j.jar,jaxen-1.1-beta-6.jar.

Import java.io.IOException;

Import Java.io.InputStream;

Import org.dom4j.Document;

Import org.dom4j.DocumentException;

Import Org.dom4j.io.SAXReader;

Import Org.xml.sax.EntityResolver;

Import Org.xml.sax.InputSource;

Import org.xml.sax.SAXException;

public class Validatingdom4j {

public static void Main (string[] args) throws Documentexception,

saxexception {

Saxreader reader = new Saxreader ();

Turn on validation

Reader.setvalidation (TRUE);

Validates the specified input.

Reader.setfeature ("Http://apache.org/xml/features/validation/schema", true);

Locate the XSD file location reader.setentityresolver (new Entityresolver () {

@Override

Public InputSource resolveentity (string publicid, String systemid) throws Saxexception, IOException {

InputStream in = Validatingdom4j.class. getResourceAsStream ("book.xsd");

InputSource Source = new InputSource (in);

return source; }

});

InputStream in = ValidatingDom4j.class.getResourceAsStream ("Book.xml");

Document doc = Reader.read (in); } }

Validation of XML files in Java